Environmental archaeology in Ireland 9781782974789, 1782974784, 9781782974802, 1782974806

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Environmental Archaeology in Ireland

Eileen M. Murphy Nicki J. Whitehouse

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Published by Oxbow Books, Oxford, UK

© Oxbow Books and the individual authors, 2007 9781782974789

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Oxbow Books, Oxford, UK (Phone: 01865-241249; Fax: 01865-794449)

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The David Brown Book Company PO Box 511, Oakville, CT06779 (Phone: 860-945-9329; Fax: 860-945-9468)

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from our website www.oxbowbooks.com

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Cover: Devenish Island, Co. Fermanagh. Photograph taken by Tony Corey of the Environment and Heritage Service: Built Heritage, DoE Northern Ireland

Printed and bound in Great Britain by Hobbs the Printers Ltd, Totton, Hampshire

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This volume is dedicated to Colm and Phil for all their help and support over the years

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Table of Contents Title Page Copyright Page Dedication Acknowledgements List of Contributors Introduction 1 - Radiocarbon Dating: A Practical Overview 2 - Dendrochronology and Lessons Learned from Irish Examples 3 - The Use of Tephra in Linking European Sequences of Terrestrial, Lacustrine, Marine and Ice Palaeoenvironmental Records 4 - Human Osteoarchaeology in Ireland 5 - Mammal Bone Studies from Prehistoric Irish Sites 6 - Exploitation of Birds and Fish in Historic Ireland: A Brief Review of the Evidence 7 - Molluscs and Middens: The Archaeology of ‘Ireland’s Early Savage Race’? 8 - The Study of Fossil Insect Remains in Environmental and Archaeological Investigations: An Irish Perspective 9 - Environmental Archaeology in Ireland: A Personal and Archaeobotanical Perspective 10 - Wood and Charcoal Research in Ireland 11 - The Study of Non-Wood Plant Macro-remains: Investigating Past Societies and Landscapes 12 - Pollen Analysis and Archaeology in Ireland 7

13 - Alluvial Geoarchaeology in Ireland 14 - Multi-proxy Approaches to Palaeohydrological Investigations of Raised Bogs in Ireland: A Case Study from Derryville, Co. Tipperary 15 - Exploring the Role of Environment in Wetland Archaeological Contexts in Ireland 16 - Heritage Legislation and Environmental Archaeology in Ireland

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Acknowledgements As editors we would firstly like to thank our contributors who willingly gave up their time to research and write chapters of the highest standard. When the book idea was originally conceived we were of the opinion that much of the valuable environmental archaeological work being undertaken on Irish material was going unnoticed outside the island. We hope the production of this book will go some way towards addressing this problem and that the book will form a valuable text book for all those interested in the discipline from an Irish perspective. Without the breadth of knowledge and enthusiasm for their specialist areas clearly demonstrated by the contributors, however, the book would not have been possible. We are extremely grateful to all the leading figures within the field of environmental archaeology who graciously undertook peer-review of each of the contributions–Prof. Don Brothwell (University of York), Prof. Tony Brown (University of Exeter), Mr. Richard Brunning (Somerset County Council), Dr. Mike Charles (University of Sheffield), Prof. Dan Charman (University of Plymouth), Dr. Colm Donnelly (Queen’s University Belfast), Dr. Allan Hall (University of York), Dr. Andy Howard (University of Birmingham), Dr. Harry Kenward (University of York), Mr. Mark Maltby (Bournemouth University), Dr. Finbar McCormick (Queen’s University Belfast), Mr. Nigel Nayling (University of Wales, Lampeter), Dr. Dave Passmore (University of Newcastle

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Upon Tyne), Prof. Jon Pilcher (Queen’s University Belfast), Dr. Rick Schulting (Queen’s University Belfast), Dr. Chris Turney (University of Wollongong, Australia) and Prof. Peter Woodman (University College Cork). Each of these recognised specialists provided many useful comments and insights which can only have served to copper fasten the quality of the contributions. We are extremely grateful to Ms. Libby Mulqueeny of the School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, for her help with much of the illustrative material contained within the volume. A special thanks is due to Mr. Tony Corey, Environment and Heritage Service: Built Heritage, for generously permitting us to use his beautiful photograph of the landscape surrounding Devenish Monastery in the lakelands of Co. Fermanagh for the front cover of the volume. We feel this picture particularly encapsulates the special qualities of the Irish landscape, where the people of Ireland have interacted with their environment over the millennia.

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List of Contributors GERARD AALBERSBERG Faculty of Earth and Life Sciences Free University of Amsterdam De Boelelaan 1085 1081 HV, Amsterdam Netherlands Email: [email protected]

MIKE G. L. BAILLIE School of Geography, Archaeology and Palaeoecology Queen’s University Belfast Belfast BT7 1NN Northern Ireland Email: [email protected]

PHILIP BARRATT School of Geography, Archaeology and Palaeoecology Queen’s University Belfast Belfast BT7 1NN Northern Ireland Email: [email protected]

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ANTHONY G. BROWN Department of Geography School of Geography, Archaeology and Earth Resources University of Exeter, Amory Building Rennes Drive Exeter EX4 4RJ England Email: [email protected]

DAVID M. BROWN School of Geography, Archaeology and Palaeoecology Queen’s University Belfast Belfast BT7 1NN Northern Ireland Email: [email protected]

CHRISTOPHER J. CASELDINE School of Geography, Archaeology and Earth Resources University of Exeter Cornwall Campus Treliever Road, Penryn Cornwall TR11 9EZ England Email: [email protected]

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BENJAMIN R. GEAREY Institute of Archaeology and Antiquity University of Birmingham Edgbaston Birmingham B15 2TT England Email: [email protected]

PETER GLANVILLE John Barnett and Associates Ltd. CSA Group, Unit 7 Dundrum Business Park, Windy Arbour Dublin 14 Republic of Ireland Email: [email protected]

SHEILA HAMILTON-DYER School of Conservation Sciences Bournemouth University Talbot Campus Poole Dorset BH12 5BB England Email: [email protected]

MERIEL MCCLATCHIE Institute of Archaeology University College London 31–34 Gordon Square

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London WC1H 0PY England Email: [email protected]

CONOR MCDERMOTT School of Archaeology Newman Building University College Dublin Belfield, Dublin 4 Republic of Ireland Email: [email protected]

MICHAEL MONK Department of Archaeology University College Cork Cork Republic of Ireland Email: [email protected]

EILEEN M. MURPHY School of Geography, Archaeology and Palaeoecology Queen’s University Belfast Belfast BT7 1NN Northern Ireland Email: [email protected]

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EMILY V. MURRAY School of Geography, Archaeology and Palaeoecology Queen’s University Belfast Belfast BT7 1NN Northern Ireland Email: [email protected]

JOHN J. Ó NÉILL School of Archaeology Newman Building University College Dublin Belfield, Dublin 4 Republic of Ireland Email: [email protected]

JON R. PILCHER School of Geography, Archaeology and Palaeoecology Queen’s University Belfast Belfast BT7 1NN Northern Ireland Email: [email protected]

GILL PLUNKETT School of Geography, Archaeology and Palaeoecology Queen’s University Belfast Belfast BT7 1NN

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Northern Ireland Email: [email protected]

PAULA J. REIMER School of Geography, Archaeology and Palaeoecology Queen’s University Belfast Belfast BT7 1NN Northern Ireland Email: [email protected]

INGELISE STUIJTS The Discovery Programme 63 Merrion Square Dublin 2 Republic of Ireland Email: [email protected] and: [email protected]

MARTIN THORP School of Geography, Planning and Environmental Policy Newman Building University College Dublin Belfield, Dublin 4 Republic of Ireland

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NICKI J. WHITEHOUSE School of Geography, Archaeology and Palaeoecology Queen’s University Belfast Belfast BT7 1NN Northern Ireland Email: [email protected]

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Introduction Eileen M. Murphy and Nicki J. Whitehouse Environmental archaeology in Ireland has a long history of research which dates as far back as the seventeenth century to the deliberations of Molyneaux (1697) on the Giant Irish Deer and megafaunal extinctions. Throughout the nineteenth and first half of the twentieth centuries a certain amount of research was undertaken on a variety of remains in Ireland that we would now consider to fall under the auspices of environmental archaeology–human remains (e.g. Frazer 1890–91; Martin 1935), faunal remains (e.g. Wilde 1840; 1857–61), shellfish (e.g. Brunicardi 1914, 208), plant macro-remains (e.g. Jessen and Helbaek 1944; Mitchell 1946) and pollen (e.g. Erdtman 1928; Jessen 1949). It is interesting, however, to note that some of the core aspects of environmental archaeology, including palaeoentomology (e.g. Coope et al. 1979; Kenward and Allison 1994) and wood and charcoal analysis (e.g. Mitchell 1986; 1989) have only been studied within an Irish context in relatively recent times. Clearly there is still much potential for new developments within Irish environmental archaeology, particularly in view of the recent upsurge in developer-funded archaeology which is revealing substantial deposits of environmental significance. It is hoped that the current edited volume of 16 invited papers will be a testament to the healthy state of environmental archaeological research in Ireland at the beginning of the 18

twenty-first century. The papers each focus on a particular aspect of environmental archaeology and include such specialist areas as radiocarbon dating, dendrochronology, palaeoentomology, human osteoarchaeology, palynology and geoarchaeology. Each contribution provides an introduction to the techniques and methodologies, approaches and potential of the different aspects of environmental archaeology currently being used within an Irish context. The researchers have all included pertinent case studies within their chapters that should heighten awareness of the profusion of high standard environmental archaeological research that is currently being undertaken on Irish material. In addition, each contributor has highlighted gaps in knowledge and made recommendations for potential ways forward for their aspects of the discipline; these insights should act as a valuable springboard for ideas and future projects. It is hoped that the book will provide a key text for students and practitioners of archaeology, archaeological science and palaeoecology and that it will serve as a baseline upon which future environmental archaeological studies within Ireland can be built. The book is divided into five thematic sections–Dating, Humans and Animals, Plants, Approaches to Environmental Archaeology and Legislation. The first group of papers focus on three of the main scientific dating methods used by environmental archaeologists–radiocarbon dating, dendrochronology and tephrochronology. Phil Barratt and Paula Reimer begin their chapter with the statement: ‘Today it would be difficult to imagine archaeology without the availability of radiocarbon dating’. Never a truer word was said and this is reflected in the evidence for the extensive use of radiocarbon dates apparent throughout the volume. We are

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fortunate that Ireland is home to one of the leading high-precision radiocarbon laboratories in the world–the 14CHRONO Centre at Queen’s University Belfast–which is soon to house an Accelerator Mass Spectrometry (AMS) facility. The paper begins by providing an overview of the development of the radiocarbon dating technique since the 1940s. The principles and rationale behind the method are outlined and the differences between the Gas Proportional Counting, Liquid Scintillation Counting and AMS methodologies are discussed. The principles of fractionation correction and calibration are explained in addition to the age limitations and accuracy of the technique. Valuable guidelines as to how best to obtain optimum dating results are provided and practical advice is imparted concerning sample suitability, the storage and handling of samples and sample submission. Information is provided as to how the resultant raw dates should be calibrated and conveyed to a wider audience. The authors make the point that dating is of particular importance to environmental archaeologists investigating the impact of humans on a landscape that is changing on a range of temporal scales. They conclude by suggesting that more interaction between environmental archaeologists and radiocarbon laboratory personnel, with the exchange of ideas and advice at the outset of archaeological projects, will help aid in sample selection and the interpretation of results. In Chapter 2, David Brown and Mike Baillie review the success rates with which dendrochronology can be applied in Irish wetland archaeological situations. They highlight some of the practicalities associated with this technique and the importance of completeness of samples with respect to sapwood as a limiting factor for dating precision and

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subsequent archaeological interpretation. In particular, they draw attention to the fact that it is necessary for archaeologists to strive to get the best and most refined dates possible for their sites, if they wish for the significance of their sites to fit into the wider context of archaeological sites. This will allow archaeologists to establish the relationship between precisely-dated environmental change and archaeological activity and what they term ‘the world of real chronology’ that is currently being developed by dendrochronologists and ice-core workers, among others. Brown and Baillie then provide a series of case studies where dendrochronology has been applied. In the first instance, they highlight the use of the technique in the study of Late and Post-Medieval house structures and sequences. Two case studies are provided: Rathfarnham Castle, Dublin, where dendrochronology was able to provide a precise chronology of the building of the castle and Cultra House, Co. Down, which illustrates the difficulties presented by the re-use of timbers. Finally, the authors focus on the significance of the Irish tree ring chronologies in helping to piece together new pictures of the Irish past, such as understanding of past environmental events and the relationship between ‘events’ identified in the tree ring record with societal change. Keeping with the dating theme, Jon Pilcher draws attention to the valuable chronological and stratigraphic role tephrochronology can provide in the study of past environments, especially in north-west Europe where well-dated Icelandic tephras (volcanic ashes) can reach suitable preservational environments such as lakes and peat bogs. Visible tephra layers have been used extensively in the study of the early settlement of Iceland and the Faroe islands, but modern techniques now allow users to extract much

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smaller amounts of tephras (also known as micro-tephras), allowing the technique to be extended to Ireland, Britain and other parts of north-west Europe (see Turney et al. 2006). These improved concentration and detection methods now permit the use of these valuable chronological markers in a wide range of Quaternary deposits. Following a discussion of the practicalities of the technique, including sampling, extraction and analysis of geochemical data, Pilcher then discusses the various uses of tephra as a chronological and correlation tool and presents a case study where tephra was recently used in the study of environmental change in the Lafoten Islands off the coast of Norway, highlighting its ability to correlate episodes of environmental change across the North Atlantic region. There are some difficulties associated with the technique, however, not least the time-consuming nature of analysis and the uneven distribution of tephra; there can be considerable variation in the distribution of the tephra from even within the same lake basin and there are often problems associated with the similarity of tephra geochemistries (e.g. Pyne-O’Donnell 2006). The second section of the book deals with humans and animals (mammals, birds, fish, shellfish and insects) and the role they have played in environmental archaeological studies within an Irish context. Eileen Murphy starts this part of the volume by providing a review of human osteoarchaeology in Ireland, starting with a brief history of the discipline, followed by an overview of the main methodologies employed in the general analysis of archaeological human skeletal remains. The second part of her paper provides an insight into why such analyses are important for furthering our understanding of the human past within an Irish context,

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focusing on a series of themes and case studies, including demography, health and disease (such as diffuse idiopathic skeletal hyperostosis, leprosy and tuberculosis), activity markers upon skeletons, diet and trauma. In particular, she draws attention to the importance of a adopting a biocultural approach, whereby the osteoarchaeological evidence is not studied in isolation but rather in conjunction with the historical and archaeological information relating to a particular site. By using such an approach it is possible, for example, to identify and interpret unusual populations, such as those in cilliní or ecclesiastical burial grounds. She concludes by indicating that human osteoarchaeology within Ireland is still progressing and there is great potential for the development of collaborative synthesis projects between specialists working on the island, as well as the opportunities offered by some of the specialised biomolecular techniques, such as aDNA and stable isotope analysis. Finbar McCormick’s paper largely reviews the evidence that has emerged from the study of mammal bones from Irish prehistoric sites. Knowledge in this field has been greatly enhanced over the past four decades when archaeozoological remains began to be analysed on a more routine basis than before as a result of the pioneering research undertaken on the Newgrange faunal remains by Louise van Wijngaarden-Bakker (1974). He identifies how some gaps still remain to be filled, however, particularly for the Neolithic and Late Iron Age periods. He highlights how the more recent evidence has revealed significant errors in the understanding of prehistoric animal exploitation. Prior to 1970, it was assumed that the Mesolithic economy was largely based on coastal shellfish exploitation, for example, supplemented by fishing and hunting, particularly for Red

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Deer. It is now known that large oyster middens are more of a Neolithic phenomenon, while Red Deer appears to have been absent from Ireland during the Mesolithic, with wild pig forming the main component of the Mesolithic meat diet. McCormick reviews the evidence for animal exploitation from the Mesolithic through to the Iron Age period. He looks at the composition of the faunal assemblages available from settlement sites for each period as well as animal remains derived from ritual contexts. This data provides information concerning the species of animals that were being exploited and the economic form that this exploitation took. Such information can provide valuable insights concerning the nature of the environment that both the animals and humans inhabited throughout the prehistoric period. This would appear to be particularly true for the Late Bronze Age assemblage derived from the island site of Dún Aonghasa, Co. Galway, where unusually sheep/goat were found to have been predominant. It is considered probable that this situation may have arisen due to the harsh environment of Arran Island which would have been most suitable for grazing hardy sheep. This theory finds support in the evidence for an unusually high slaughter rate of young calves at the site which is thought to be an indication of fodder shortage and is a recognised characteristic of faunal assemblages derived from marginal Atlantic sites. McCormick concludes by stating that we are now in a position to prioritise areas of future research within Irish archaeozoological studies to help fill the gaps in knowledge. He makes reference to the use of genetic studies as a means of further developing our understanding of the origins and nature of the animals of prehistoric Ireland. Sheila Hamilton-Dyer reviews the evidence derived from bird and fish remains recovered from historic period sites in

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Ireland. She makes the point that bird and fish remains have consistently formed a minor, but important, component of archaeological faunal assemblages. One of the main problems with bird and fish bone studies within Ireland has been related to a general lack of sieving on archaeological sites. Where this methodology has been employed it has become clear that fish, in particular, are being under-represented in Irish assemblages. The paper includes a valuable overview of methodological and taphonomic considerations and provides a clear justification as to why the study of archaeological bird and fish bone assemblages is of importance. This is followed by a detailed review of the evidence derived from bird bones and fish bones in two separate sections which each deal with sites dating from the Early Christian period through to Post-Medieval times. Despite the limitations highlighted in the earlier part of the paper, trends in consumption and exploitation are beginning to emerge. Early Christian coastal sites, such as those at Illaunloughan, Co. Kerry, and Doonloughan, Co. Galway, have revealed evidence for the exploitation of a large variety of local marine fish and birds. Irish urban Medieval centres, such as Dublin, thought to have undergone major influence from Anglo-Norman settlers, appear to provide the first evidence for the introduction of domestic fowl, geese and ducks. This is in direct contrast to sites located in areas outside Anglo-Norman influence where domestic birds occur in much smaller proportions. As was the case for archaeological mammal bones, Hamilton-Dyer is of the opinion that it is now possible to identify notable gaps in knowledge for the bird and fish bone record. For the historic period the evidence is particularly lacking for low status rural sites and inland sites in general. A notable aspect of all Irish fish bone assemblages is the presence of marine as opposed to freshwater species, a finding which remains to be 25

satisfactorily explained. Another point of interest raised in the paper includes the discrepancies that exist between the documentary and archaeological records for bird and fish exploitation in historic Ireland, which clearly highlights the need for archaeologists to use documents as a source of information with caution. The paper concludes with a discussion of priorities for future research. Hamilton-Dyer is of the opinion that the study of the introduction and past distribution of bird and fish species is an area of much potential within an Irish context. Other aspects of research that she suggests could be developed include the application of DNA and metrical techniques to enable the identification of the various different goose and duck species and to gain a clearer understanding of physiological changes that may have been due to domestication and husbandry techniques. Furthermore, with the ever increasing body of archaeological bird and fish bone data from Ireland it is becoming possible to compare this information to that derived from Britain and other parts of Europe. Shell middens are very well known sites within an Irish context and middens and molluscs form the topic of Emily Murray’s paper. She starts by introducing the nature of archaeological deposits which contain shellfish remains and highlights how their real value does not lie in the reconstruction of past diet but rather in the potential insights they can provide concerning wider aspects of a site’s function, culture, economy and environment. She highlights how early researchers had assumed the producers of shellfish middens relied on shellfish for the greater part of their sustenance and how they were the product of poor and primitive folk. Following on from this she points out that, despite developments in scientific techniques, understanding

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of Irish shell middens has only marginally progressed. The majority of the paper then focuses on attempting to address this issue by providing a detailed review of shellfish exploitation from Mesolithic through to Early Christian times. Material recovered from Late Mesolithic sites in Counties Dublin and Louth has indicated that a wide variety of shellfish, in particular oysters, periwinkles and carpet shells, were exploited by the people who used these temporary habitation sites. The exploitation of the coastal environment appears to have continued into the Neolithic period. One of the most interesting aspects of the Neolithic shell deposits is the presence of very large middens, largely comprising oysters, from certain parts of Ireland, including Ballysadare Bay, Co. Sligo. Murray is of the opinion that the occurrence of such middens is an indication that oysters were eaten in vast quantities by some during the Neolithic, and may be an indication that people reverted to a hunter-gatherer existence at least on occasion. Understanding of shellfish exploitation during the Bronze Age and Iron Age is less well understood, although excavation at Bronze Age sites such as False Bay, Co. Galway, and of Iron Age middens in Mannin Bay, Co. Galway, indicate there was at least some exploitation and settlement along the coast during these periods. Shellfish have been recovered from a variety of Early Christian period coastal sites, including Doonloughan, Co. Galway, as well as on inland sites and in Viking urban contexts, thereby suggesting that they were still of importance during historic times. The paper concludes with a discussion of the vulnerability of coastal midden sites, largely as a consequence of erosion, and stresses the value of intertidal surveys such as that recently undertaken in Strangford Lough, Co. Down (McErlean et al. 2002). The potential of material derived from excavated shell middens for the purposes of refining the 27

accuracy of radiocarbon calibration of marine-derived materials is also highlighted. Concluding the section on humans and animals Nicki Whitehouse provides a review of fossil insects in Irish environmental and archaeological investigations. She begins by outlining the history of the discipline and by highlighting the different insect groups that are available for analysis and how they can make a contribution to the understanding of past environments. The underlying principles and methodological issues concerning sampling, identification and the analysis of insect material are then discussed. The chapter proceeds with a comprehensive review of the available fossil insect evidence from Ireland, starting with the knowledge of climate change inferred from fossil insects. This work is important not just in terms of understanding past climates and how these would have impacted upon prehistoric populations, but also within the context of global climate change. Relatively little work has been undertaken on fossil insects from the early part of the Holocene, although recent work by the author on Later Mesolithic and more recent prehistoric sites, including Sluggan Bog, Co. Down, and Ballyarnet Lake, Co. Derry, has provided important new data on the development of the Irish landscape. The final section of the paper reviews the contribution of urban and rural archaeological insect faunas from historic period Ireland. An overview is provided of published research on Viking and Medieval deposits from Dublin and the results of study on a new Post-Medieval assemblage from Newmarket, also in Dublin. The results of the latter study indicate that living conditions at Newmarket were generally not salubrious. Specific finds of interest include the first identification of both the bedbug and oriental cockroach from an Irish archaeological context. The findings

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from these urban contexts are compared with those derived from the rural Early Christian rath site at Deer Park Farms, Co. Antrim, where waterlogging of the site resulted in extraordinary levels of preservation. The nature of the insect fauna suggested that foul material, probably derived from animals, had been left exposed on the living surfaces of the rath, while abundant human parasites were found associated with bedding structures. The paper concludes with a number of recommendations to help fossil insect studies develop within Ireland. Whitehouse is particularly of the opinion that further investigation of prehistoric settlement sites is necessary in addition to the training of new practitioners to undertake further research on Irish material. The third part of the book focuses on the role of plant remains within Irish environmental archaeology. Michael Monk begins the section with a personal and archaeobotanical overview of environmental archaeology in Ireland. He reviews the development of the discipline, with particular reference to the study of plant remains, from the nineteenth century onwards. He also provides a survey of the development of environmental archaeological teaching within third level education. He believes that environmental archaeology was slower to take off in Ireland compared to Britain and discusses why this may have been the case. He is of the opinion that the situation arose as a result of a variety of factors, including a lack of emphasis on environmental archaeology in the education of archaeologists and the relatively small impact that processual archaeology made on Irish archaeologists compared to their British counterparts. There were exceptions to this situation, however, including Martin Jope in Queen’s University Belfast and Michael O’Kelly in University College Cork, who did display an

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interest in environmental aspects of archaeology during the 1960s and early 1970s. Monk is of the opinion that the future is now brighter than ever before for Irish environmental archaeology as a result of an increasing number of environmental archaeologists in more regular long term employment within both the commercial archaeological sector and the universities. The second part of the paper provides some suggestions as to how to move the study of plant macrofossils forward within an Irish context. He stresses the importance of attempting to synthesise the grey literature that has been produced as a result of the upsurge of developer-led archaeology in recent times. In addition, he believes that multidisciplinary research projects which draw together diverse archaeological approaches have the potential to both improve and challenge the interpretive basis of our research within an Irish context. Ingelise Stuijts discusses the state of wood and charcoal research in Ireland and explores the value of the analysis of these ecofacts to archaeological investigation and a history of the discipline in Ireland. She provides information on methodologies, together with details of how to sample for wood and charcoal. Wood was readily available in prehistoric times and hence was used for a variety of purposes, from the building of structures to the crafting of domestic and artistic objects. Much of this wood ultimately ended up in domestic fires. Outside Ireland, the study of wood and charcoal has long been an integrated part of archaeological excavations. Such studies have provided significant insight into wood usage, woodland management and woodland changes over time. The last ten years has, however, seen a growing interest in wood and charcoal analysis in Ireland, which has resulted in some very interesting studies. Three examples of wood and

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charcoal research in Ireland are presented; data from Derryville Bog show how wood usage changed over time and it is suggested that the observed changes seen in wood usage over time may point to the impact of anthropogenic changes in the local landscape in the marginal areas surrounding the bog. Evidence from fulachta fiadh and West End, Dublin, are also presented. Stuijs points out that understanding wood usage should go beyond wood identification and that future research should incorporate more aspects of wood analysis, such as the examination of annual ring patterns, wood quality and insect damage. She concludes that it is only through the full integration of environmental analysis and archaeological excavation that a deeper understanding of the life and environment of prehistoric people will be realised. Meriel McCatchie explores the importance of the non-wood plant macrofossil record within Irish environmental archaeology. She presents a methodological review of the approaches and techniques used in the retrieval, identification and interpretation of non-wood plant macro-remains from archaeological deposits. The range of information that can be gleaned from the study of plant macro-remains preserved through various mechanisms is explored and the benefits of integration with a range of other archaeological and environmental approaches are also considered. Development of the study of the discipline in Ireland is explored, but she also draws attention to the lack of well-funded, interdisciplinary projects combining archaeological excavations with a range of environmental analyses, including archaeobotanical remains, in Ireland. The work of the Discovery Programme is an exception to this, such as the ongoing research project at the waterlogged Mesolithic site at Derragh, Lough Kinale, Co. Cavan. A guide towards the

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selection and processing of samples is presented, and methods relating to the extraction and identification of plant macro-remains are examined. A case study from Kerlogue, Co. Wexford, is presented, demonstrating an approach in the interpretation of plant macro-remains by assessing the significance of material from prehistoric and Early Medieval deposits. McClatchie also draws attention to a number of problems for the discipline in Ireland, problems which are also prevalent in a number of other environmental archaeological disciplines, such as palaeoentomology. There are very few practising archaeobotanists specialising in Ireland, which has resulted in a situation where interpretations suggested by individual workers often fail to be critically discussed within the Irish community. Moreover, there has been a lack of integration between individual site assemblages and the archaeological evidence within overall excavation reports (like many other environmental approaches, such specialist reports may often be relegated to appendices, with little or no attempt at integration) and thus the archaeobotanical record can often be perceived as ‘dealing with interactions between plants and various ecological factors rather than interactions between people, plants and environments’. She also suggests that there is a lack of cohesion in research, combining with the small number of studies being published, resulting in a situation whereby international audiences are often not well-informed about recent and current work in Irish archaeobotany. A good example of this problem is shown in a recent publication which explores the archaeobotanical record from Europe, but where a discussion of the Irish record is lacking (Colledge and Connolly in press).

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Gill Plunkett’s contribution focuses on the well-established environmental archaeological technique of pollen analysis that enables the reconstruction of past vegetation changes in the landscape. She makes the point that from an archaeological perspective, pollen records contain an important history of human interference with the natural environment and how they have the potential to provide further insights into human activity that can greatly complement and augment the archaeological record. The paper commences with a history of archaeology-related pollen studies in Ireland from the 1920s up until recent times before moving on to a methodological overview of palynological techniques. It then examines the role pollen analysis has played in archaeological research in Ireland and draws on three cases studies to illustrate the diverse contributions it can make to the study of past human activity. The first case study focuses on the contentious debate concerning the Elm Decline and the earliest farming in Ireland and clearly portrays the complexity of interpreting the pollen record, while also drawing attention to the potential of the technique to shed light on activity not apparent from the archaeological record. The second study concentrates on recent findings derived from pollen studies undertaken near Late Bronze Age hillforts. This information has revealed that, whatever role these sites had, at least a number of them were supported by a thriving, mixed farming economy that persisted for several centuries. The final case study reviews the extensive pollen evidence now available from the Late Iron Age and Early Medieval periods which has revealed that a widespread expansion in farming pre-empted the arrival of Christianity in the island, with a further intensification of agriculture having been associated with the founding of monastic enclosures and the proliferation of secular sites 33

during the seventh century. The pollen record during this period also complements the available archaeo-environmental and literary evidence for a well-developed, mixed agricultural economy, thereby highlighting the extent of anthropogenic impact on the landscape at this time. One of the main conclusions of the paper is to highlight how considerable opportunities remain for the integration of archaeological and palynological research to enable a more holistic reconstruction of past human interactions with the landscape. In the fourth section of the book three approaches that have been applied to environmental archaeological research within an Irish context are explored, namely alluvial geoarchaeology, palaeohydrological investigations and wetland archaeology. Tony Brown and colleagues provide a detailed summary of alluvial geoarchaeology in Ireland. There has been relatively little research in this area in Ireland, although they draw attention to the fact that the great Irish Quaternary scientist, G. F. Mitchell could perhaps be viewed as the father of Irish geoarchaeology. The topographic relief and high rainfall of Ireland, especially within the midlands area have ensured that the country is covered by a patchwork of lakes, raised mires and alluvial floodplains. These landforms provide the potential for multi-proxy and multi-scale environmental reconstruction. The linkage of lakes, bogs and alluvial areas provided important places for activity during the Mesolithic, such as those associated with the River Bann, whilst during the Neolithic and later periods alluvial environments appear to have been important foci for ritual activity and deposition. The importance of alluvial places continued into the Early Christian period, with lake and riverine islands becoming favoured ecclesiastical establishments. The relationship between archaeology and

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alluvial environments is thus clear and has enormous potential. This potential is explored through several detailed case studies, including raised mire and alluvial data from the Little Brosna Valley in the middle Shannon Basin, the Liffey Basin in Co. Kildare and the River Lee and the Gearagh in Co. Cork. These, along with selected other studies illustrate that the alluvial geoarchaeology of Ireland has yet to be seriously evaluated and the great potential that exists herein. The conclusion reached is that the low-energy environments of most Irish floodplains have almost certainly entombed abundant evidence of alluvial landscape change, which awaits excavation. There are, however, obvious problems concerning high water-tables, but there are also unique opportunities through the combination and linkage of alluvial, lacustrine and mire based records of environmental change and the human creation of the Irish landscape. Chris Caseldine and Ben Gearey draw attention to palaeohydrological investigations of raised Bogs in Ireland, by highlighting work undertaken by them and their colleagues at Derryville Bog, Co. Tipperary. They discuss the value of raised (ombrotrophic) mires for the study of past climate change, via palaeohydrological sequences. Although there have been some previous palaeohydrological studies in Ireland, they point out that there has been little attempt made to link such investigations to archaeological investigations and sequences, which is one of the strengths of the Derryville study. They discuss the strengths and weaknesses of the three main palaeohydrological proxy techniques of plant macrofossil, peat humification and testate-amoebae analyses and present in detail the results from one peat sequence (DER18) from Derryville. The different proxies show similar patterns, although there are discrepancies in the timing and

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magnitude of palaeohydrological change, and suggest that the development of the bog appears to have been driven largely by autogenic (internal) rather than allogenic (e.g. climate) factors. The need for further, multi-proxy palaeohydrological studies in Ireland is stressed and the context this can provide for wetland archaeological sites highlighted. Gill Plunkett and Conor McDermott highlight the importance of wetlands as significant features of the Irish landscape and how wetland and environmental archaeology are strongly interlinked. This is because wetland environments preserve many of the eco-facts which are integral to environmental archaeology, and have been central to the reconstruction of past landscapes and environments, ever since the inception of archaeology and palaeoecology in Ireland. Following a history of the discipline and its contribution, the authors focus on two case studies, to illustrate how the study of wetland environments has helped us to understand past human activity. The first example is from the Lower Bann floodplain and its associated Later Mesolithic archaeology embedded within diatomite and peat deposits, and illustrates how the dynamic floodplain and its ecosystem created a situation rich in environmental resources. The conditions which created the preservation of the environmental record, however, have also impacted the location of former occupation sites and created a partial archaeological record, impacting on their survival and identification. Thus, fluctuating water-levels associated with the River Bann contributed significantly to flooding and depositional processes, whilst also eroding, obscuring or obliterating much evidence for human occupation. Plunkett and McDermott then draw attention to the accumulating body of archaeological sites in raised bogs, namely trackways. The distribution of many of these structures reveals significant

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continuity in the use of particular locations through many periods, although at some sites, such as Derryville Bog, dating evidence indicates that trackway construction and bog use was often episodic, and that for some periods at least, such as the Middle to Late Bronze Age, may have taken place during periods of drier/warmer conditions. Plunkett and McDermott conclude by highlighting the opportunities provided by the study of wetlands within their wider context to address the relationships between socio-economic, cultural and environmental factors within the archaeological record. The fifth and final section of the book comprises a paper by John Ó Néill which provides an important overview of heritage legislation and environmental archaeology for the island of Ireland. Following the partition of Ireland into Northern Ireland and Saorstát Eireann in 1921, the two separate legislative jurisdictions replaced the existing Ancient Monuments Protection (Ireland) Act of 1882 with the Ancient Monuments Act (Northern Ireland) 1926 and the National Monuments Act 1930, respectively. As such, it has been necessary for Ó Néill to provide a separate review of the development of heritage legislation for both Northern Ireland and the now Republic of Ireland. The impact of such legislation on environmental archaeology is examined, both in the context of its protection and policy against the reality of its practice, particularly with regard to excavation. The evolution of the legislation and its current status is central to understanding its influence on the practice of environmental archaeology in Ireland. Ó Néill concludes with a summary statement which makes the point that while technical and academic standards in Irish environmental archaeology can be adequately monitored through peer review and debate, the legislative protection afforded to environmental

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archaeological materials is explicit in the Republic of Ireland but non-specific in Northern Ireland. In both jurisdictions, the licensing system for archaeological excavations provides a safety net whereby threats to soils and other materials utilised in environmental archaeological studies can be identified and mitigated. The legal impetus to engage in the study of environmental archaeology as part of this work, however, lies solely with the conditions under which the licences for archaeological excavation are issued.

Conclusions It is inevitable that a number of underlying themes and recurrent lines of thought will become evident in a volume such as this. Most of the authors lament the lack of publication of many specialist reports that are of relevance to environmental archaeologists. This situation has meant that it is virtually impossible to undertake synthesis studies on the different aspects of environmental archaeology which have the potential to enable the identification of broader trends in relation to chronology, status, location etc. It is clearly of major importance to archaeologists and environmental archaeologists alike that this situation is rectified on both sides of the border and that the vast amount of grey literature becomes more publicly accessible, perhaps via publication on the internet. On a more positive note many of the contributors highlight the value of multidisciplinary projects which involve close communication between archaeologists and environmental archaeologists from the earliest stages of the research. One shining example of a highly successful project of this nature, which is referred to frequently throughout the volume, is the Lisheen Archaeological Project which involved the

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excavation of Derryville Bog, Co. Tipperary, by Margaret Gowan and Co. Ltd. during the late 1990s. The results of this research project have recently been published as a monograph (Gowen et al. 2005). In addition to archaeological excavation the project included pollen, peat stratigraphy, wood and insect analyses in addition to peat humification, testate amoebae and plant macrofossil studies. Plunkett and McDermott (this volume) have gone so far as to say that this study ‘marks the acme of combined wetland-environmental studies in Irish archaeology to date’. However, this project tends to be the exception rather than a rule. Too often, environmental archaeological results are relegated to report appendices and there is limited opportunity for the environmental data to be fully integrated with the archaeological results. We believe that a more holistic approach, which attempts to integrate all the various lines of evidence, can be immensely valuable and allow researchers to ask more searching questions of the archaeological record. It is therefore pleasing that the importance of the environmental archaeological record is explicitly recognised within the recently published Heritage Council document–Research Needs in Irish Archaeology (2006)–in which key research themes have been identified. The relationships between climate, environment and societal change are one of the recognised themes, an area which is highlighted by several contributors to this volume. Other important areas where environmental archaeology can make an important contribution include ‘Landscape and Settlement’ and ‘Territories, Boundaries and Cultural Identity’. If we are to address some of these themes in a holistic way, however, much greater interaction between different specialists needs to happen, with a move towards integration of the various lines of evidence.

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Although much research has been undertaken on environmental archaeology within an Irish context a lot more work remains to be done. Ireland has a rich natural and archaeological landscape brimming with potential in addition to an increasing number of highly skilled environmental archaeologists. It is up to the broader archaeological community to work closely with the University, Commercial and Government sectors to ensure that we do not waste the opportunities presently available to us and that we continue to strive to develop Ireland’s position within the field of environmental archaeology.

References Brunicardi, M. 1914. The shore-dwellers of ancient Ireland. Journal of the Royal Society of Antiquaries of Ireland 44, 185–213. Colledge, S. and Connolly, J. (eds.) in press. The Origins, Spread and Use of Domestic Plants in Neolithic Southwest Asia and Europe. London: University of London Press. Coope, G. R., Dickson, J. H., McCutcheon, J. A. and Mitchell, G. F. 1979. The Late-glacial and early postglacial deposit at Drumurcher, Co. Monaghan. Proceedings of the Royal Irish Academy B79, 63–85. Erdtman, G. 1928. Studies in the postarctic history of the forests of northwestern Europe. Geologiska Föreningens i Stockholm Förhandlingar 50, 123–92. Frazer, W. 1890–91. A contribution to Irish anthropology. Journal of the Royal Society of Antiquaries of Ireland 21, 391–404.

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Gowen, M., Ó Néill, J. and Philips, M. (eds.) 2005. The Lisheen Mine Archaeological Project 1996–1998. Bray: Wordwell. Jessen, K. 1949. Studies in Late Quaternary deposits and flora-history of Ireland. Proceedings of the Royal Irish Academy 52B, 85–290. Jessen, K. and Helbaek, H. 1944. Cereals in Great Britain and Ireland in prehistoric and early historic times. Det Kongelige Danske Videnskabernes Selskab: Biologiske Skrifter 3, 1–68. Kenward, H. K. and Allison, E. P. 1994. A preliminary view of the insect assemblages from the early Christian rath site at Deer Park Farms, Northern Ireland, pp. 89–107 in Rackham, D. J. (ed.), Environment and Economy in Anglo-Saxon England (CBA Research Report 89). York: Council for British Archaeology. Martin, C. P. 1935. Prehistoric Man in Ireland. London: Macmillan and Co. Ltd. McErlean, T., McConkey, M. and Forsythe, W. 2002. Strangford Lough; An Archaeological Survey of the Maritime Cultural Landscape. Belfast: Environment and Heritage Service. Mitchell, G. F. 1946. Evidence of early agriculture. Journal of the Royal Society of Antiquaries of Ireland 76, 16–8. Mitchell, G. F. 1986. The Shell Guide to Reading the Irish Landscape. Dublin: Country House. Mitchell, G. F. 1989. Man and Environment on Valencia Island. Dublin: Royal Irish Academy.

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Molyneaux, T. 1697. A discourse concerning the large horns frequently found under ground in Ireland, concluding from them that the great American deer call’d a moose, was formerly common in that island: with remarks on some other things natural to that country. Philosophical Transactions of the Royal Society of London, 489–512. Payne-O’Donnell, S. D. F. 2006. Three new distal tephras in sediments spanning the Last Glacial-Interglacial transition in Scotland. Journal of Quaternary Science 21, 1–12. The Heritage Council. 2006. Research Needs in Irish Archaeology: Framework for a National Archaeological Research Programme (Interim report). Kilkenny: The Heritage Council. Turney, C. S. M., van den Burg, K., Wastegård, S., Davies, S. M., Whitehouse, N. J., Pilcher, J. R. and Callaghan, C. 2006. North European last glacial-interglacial transitions (LGIT; 15–9 ka) tephrochronology: extended limits and new events. Journal of Quaternary Science 21, 335–45. Wilde, W. 1840. On the animals and antiquities recently found in Dunshaughlin. Proceedings of the Royal Irish Academy 1, 420–6. Wilde, W. 1857–61. On the ancient and modern races of oxen in Ireland. Proceedings of the Royal Irish Academy 7, 64–75. Wijngaarden-Bakker, L. H. van 1974. The animal remains from the Beaker settlement at Newgrange, Co. Meath: first report. Proceedings of the Royal Irish Academy 74C, 313–83.

Note The editors have not standardised the use of the terms Early Christian and Early Medieval throughout the volume. Both 42

terms are taken to mean the period from approximately AD 432 to AD 1169.

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1 Radiocarbon Dating: A Practical Overview Philip Barratt and Paula J. Reimer

Abstract Today it would be difficult to imagine archaeology without the availability of radiocarbon dating. It has revolutionised our ability to provide absolute dates for objects and places, and allows us to compare their place in time with others from around the world. All of this has been made possible simply from measuring the properties of a simple and abundant element–carbon. This paper describes some of the stages in the development of the technique, why it works and how to use it. We especially highlight its role in Ireland, home to one of the world’s leading high-precision radiocarbon laboratories. We aim to provide the user of radiocarbon dating with the necessary information to obtain optimum results and how best to convey these to a wider audience.

Introduction Time is inherently important to us all; we relate to our past and anticipate and plan our futures using concepts of time. The physical world we inhabit changes at scales of minutes to millennia. The environmental archaeologist attempts to describe both the human and environmental record through

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time in a way that is sensible to the nonspecialist. To do this, places and events of the human past need to be set in a chronological context along with the environments they inhabited. This is especially important when investigating the varying impact of people on a landscape that is changing on a range of temporal scales. Since its discovery in the 1940s, radiocarbon dating has provided archaeologists with a tool that has revolutionised our understanding of the human past (Renfrew 1973). An increasing appreciation of the contribution of environmental and earth science disciplines to archaeology has, in part, been enabled through an improvement of chronological control provided by radiocarbon dating. Continuing advances in methods and technology allow the practitioner to begin to unravel the relationships between temporally complex landscapes and human activity over the Holocene. As people move and work within this environment the challenges for the environmental archaeologist will change and the understanding required to date the human occupation and use of the land may well pass through many paradigm shifts.

History of Radiocarbon Dating in Ireland The Belfast Radiocarbon Laboratory, based in the Palaeoecology Centre at Queen’s University Belfast, has been providing dates since 1969 and has led the development of high precision liquid scintillation counting (Pearson 1979; 1980). Since the early days, researchers have been involved in dating archaeological and environmental materials. Contributions to the understanding of key archaeological sites in Ireland such as the Neolithic passage tombs at Newgrange and Knowth, Co. Meath, and Iron Age Navan Fort, Co. Armagh, have been taking place since the 1970s. The

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laboratory has also been involved with the dating of important sites in England such as the world renowned Stonehenge in Wiltshire (Cleal et al. 1995), and the so-called ‘Seahenge’ timber circle in East Anglia (Bayliss et al. 1999). The laboratory has worked closely with researchers from the Palaeoecology Centre at Queen’s, building a wealth of experience in archaeological and palaeoenvironmental applications. Perhaps one of the most important contributions to the latter is that of tephrochronology; the use of volcanic ash deposited after an eruption to date and correlate sedimentary horizons (see Pilcher, this volume). Assuming the tephra found in a deposit can be uniquely identified, a radiocarbon date on the sediments or plant macrofossils at the tephra horizon can be effectively transferred to other sites at the point where the same tephra has been identified. This is of course a simplified description of tephrochronology which has become an important part of the chronologist’s toolkit and the following references provide further explanation and uses of the technique–Pilcher et al. (1995), Haflidason et al. (2000), Plunkett et al. (2004) and Hall and Mauquoy (2005). The Belfast Radiocarbon Laboratory, in conjunction with the Dendrochronology Laboratory in the Palaeoecology Centre, Queen’s University Belfast, began one of the earliest European radiocarbon calibration research programmes (Pearson et al. 1977) and it has been a key centre for the development of internationally accepted radiocarbon calibration curves. The work of the Belfast Radiocarbon Laboratory formed a fundamental part of the Holocene section of the 1986 calibration curve (Pearson et al. 1986), and is still actively contributing to on-going calibration efforts including IntCal04, the latest internationally ratified calibration curve (Reimer et al. 2004). Building upon this

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work the laboratory is now at the forefront of a Southern Hemisphere calibration programme in collaboration with the University of Waikato Radiocarbon Dating Laboratory in New Zealand (Hogg et al. 2002; McCormac et al. 2004). This work has dramatically improved dating resolution below the equator and has helped to resolve the processes behind the radiocarbon offsets measured between the Northern and Southern Hemispheres (McCormac et al. 1998a; 1998b). A new Accelerator Mass Spectrometry (AMS) facility, part of the 14CHRONO Centre, based in the School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, is the first of its kind in Ireland, and will certainly enhance the chronological aspect of environmental archaeology.

Methods Where Does Radiocarbon Come From? Why and How does Radiocarbon Dating Work? Carbon (C) exists in the environment as three distinct and naturally occurring isotopes (atoms of the same element with different atomic weights)–12C, 13C and 14C. Of the three, only 14C is radioactive–the other isotopes are stable and remain chemically intact in the environment. 14C is the least common isotope, and is present as only one part in a million, million of environmental carbon. Bombardment of nitrogen (14N) by cosmic radiation in the upper atmosphere creates a constantly renewed source of 14C; once created it quickly oxidises to form carbon dioxide (CO2). Atmospheric circulation rapidly disperses this 14C ‘tagged’ CO2 around the planet. Being radioactive the 14C undergoes radioactive decay emitting a beta (ß) particle in the process. This process is immutable and is independent (i.e. unaffected) of external environmental conditions and decreases at a constant rate.

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The rate of radioactive decay for each element is unique and unvarying and determines the half-life, which is the time it takes for half of the radioactive element to undergo the decay. Once in the environment, exchange mechanisms, such as respiration in plants and ingestion by animals, incorporate the radioactive CO2 into living organisms. Gaseous exchange pathways mix it into the oceans as dissolved carbonate, which is then taken up by organisms, and chemical processes combine it into the sedimentary record. All of the exchange mechanisms ideally take place in equilibrium with atmospheric concentrations of 14CO2. However, when the exchange ceases due to biological death or sedimentary burial new 14CO2 is no longer taken up, equilibrium with the environment is broken and decay becomes the dominant process. The difference between activity measured in the dead sample and the current atmospheric concentration can be used to determine the time elapsed since exchange ceased. Since the half-life of 14C has been measured (Libby et al. 1949; Godwin 1962) and a modern standard is available to determine an initial 14C concentration, a simple equation can be used to work out the age of a sample. However, from the earliest days of radiocarbon dating it was understood that it was necessary to adopt certain assumptions when applying the technique (Libby et al. 1949; Libby 1952): — 14C would have to mix uniformly and travel through the global carbon reservoir much more quickly than the lifetime of an individual atom. — There would have to be equilibrium with the 14C available for exchange in the environment with that decaying and unavailable.

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— Organisms would take up 14C, 13C, and 12C in atmospheric proportions. — There are no post-mortem changes in the 14C other than from radioactive decay at a constant rate. As with many assumptions, these are true only in a general sense and other processes such as fractionation (Burleigh et al. 1984), ocean-atmosphere interactions, and variations in production of 14C over time required corrections to be made.

How We Measure Radiocarbon: Gas, Liquid and AMS Modified Geiger counters were used to determine the activity of samples in the early stages of radiocarbon dating (Libby et al. 1949). These simply detected the charged particles that were emitted from a radioactive sample. Improving methods and technology increased the sensitivity of the measurement equipment and reduced sample sizes, with two counting technologies becoming dominant in radiocarbon laboratories. The first development was Gas Proportional Counting (GPC), where the carbon sample is converted into CO2 and expanded into the counter. A potential voltage is applied across a thin wire running down the centre of the counter. When the 14C decays, the ß particle, which is emitted from the nucleus, is accelerated across the potential difference. The ionisation pulse measured is proportional to its initial energy. Subsequently, Liquid Scintillation Counting (LSC) was developed. For this method the sample is converted to benzene and a scintillator is added, which fluoresces when a charged particle interacts with it. With both techniques sample preparation is a key part of the process and needs to

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be very carefully controlled to obtain precise counts (McCormac 1992). During the 1970s a completely new way of determining the amount of 14C present in a sample was established: Accelerator Mass Spectrometry (AMS). This method directly measures the proportion of the carbon isotopes present in a sample which has been firstly converted to CO2 and then to graphite and pressed into a target or cathode. The target is placed in the ion source where it is coated with caesium, thereby creating carbon ions. The ions are then accelerated through an electric field and magnets are used to refract the component isotopes into detectors (Bennett et al. 1977; Nelson et al. 1977). Early tests established the viability of the technique and its potential advantages over ß counting, such as the speed of measurement and the need for much smaller samples (Muller et al. 1978). However, AMS has only recently approached the precision attainable with the high-precision LSC and GPC methods (e.g. Stuiver and Pearson 1986; McCormac et al. 1998a; 1998b). Advancements in AMS technology and sample pre-treatment procedures have led to demonstrable improvements in the precision of AMS sample measurements (Guilderson et al. 2003; Bronk Ramsey et al. 2004). The small size of the AMS sample is an advantage, in that it may be possible to select specific fractions to date, perform more rigorous chemical pre-treatments, or run multiple sub-samples. It may also be a disadvantage, however, in that small amounts of contamination can be introduced at any stage in the process (Bronk Ramsey et al. 2004). To convert the measured count rate or isotope ratio into a radiocarbon age, it is compared to that of a standard. Oxalic

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acid, produced by the U.S. National Institute of Standards and Technology, is the accepted standard for 14C. Radiocarbon, has by historical process, two half-life values in use. In order to ensure that results from radiocarbon laboratories are reproducible, frequent measurement of duplicates and/or secondary standards should be carried out. The on-going inter-laboratory comparison programme helps to ensure that results are accurate (Aitchison et al. 1990; Rozanski et al. 1992; Scott et al. 1998; 2004).

Fractionation Correction Many biological processes, such as photosynthesis, more readily incorporate the lighter carbon isotopes into the reaction product so that the initial 14C/12C ratio and 13C/12C ratio in the plant is different than that of atmospheric CO2. The two major photosynthetic pathways, C-3 and C-4, discriminate against the heavier isotope to differing degrees due to physiological differences in the way CO2 is taken up in plants (O’Leary 1981). Most temperate region trees and shrubs are C-3 plants, so named because the first product in the photosynthetic reaction contains three carbons, while tropical grasses, such as maize and millet, are C-4 plants. Physical processes also discriminate against either heavier or lighter isotopes, so that CO2 dissolved in water has a larger proportion of the heavier isotopes than the atmosphere. Thus algae and plankton, which use dissolved CO2 for photosynthesis, will also have a larger proportion of the heavier isotopes. Because the heavier 14C atom is discriminated against approximately twice as much, relative to the 12C atom, compared to the 13 C atom, a correction for isotopic fractionation can be made using the 13C/12C ratio

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(Stuiver and Polach 1977). The isotope fractionation correction may be on the order of several hundred years for C-4 plant material or for samples formed in the marine or aquatic environment.

Calibration Perhaps the most important correction made to radiocarbon measurements is to compensate for the variations in 14C concentrations over time. Research by Suess (1955) demonstrated that the amount of environmental 14C had not been constant since the nineteenth century due to emissions from industrial activity. In addition de Vries (1958) noted that appreciable variations occurred in the atmospheric 14C content. These variations were found to be the product of natural processes such as changes in the carbon cycle, solar activity and the Earth’s magnetic field (Stuiver 1961; Damon 1973; Stuiver et al. 1991; Bard 1998; Damon and Peristykh 2000; Beck et al. 2001). The effect of these processes became apparent during early practical applications of radiocarbon dating. Discrepancies of several hundred years were found when radiocarbon dates were compared with archaeological evidence and tree ring data (Libby 1963). In essence these variations or ‘wiggles’ were showing up as episodes of compressed and extended time on the radiocarbon scale compared to the calendrical scale. Unfortunately, there is no mathematical way of predicting these wiggles in the radiocarbon timeline so an empirical approach was needed. Such an approach required a material that could be independently and precisely dated, persisted for several thousand years and could be radiocarbon dated.

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Fortunately the discipline of dendrochronology had produced tree-ring chronologies in which the exact year of each tree-ring was known for a period stretching back over several thousand years (Pilcher et al. 1984). By radiocarbon dating the tree rings, an accurate ‘map’ of the location of the radiocarbon wiggles could be made. Joint efforts in America and Europe created a radiocarbon calibration curve. The curve graphically represented 14CO2 variations on one axis and calendar (dendrochronology) dates on the other. To help standardise the results from calibrating dates the radiocarbon community set about creating and disseminating an international standardised radiocarbon calibration curve. In 1986 the journal Radiocarbon published data and graphs to be used as the de facto calibration standard for users of radiocarbon dates (Stuiver and Kra 1986). This provided publicly available datasets that could be used to find (calibrate) calendar dates from radiocarbon ages. Calibration was initially rudimentary, consisting of interpolating from a table of calibrated ages or drawing lines on graphs to read the dates at an intercept (Stuiver and Pearson 1986). The introduction of computer programs such as CALIB, Cal25, OxCal and BCal, available online, has since allowed a more sophisticated approach to be taken by incorporating statistical analyses (Stuiver and Reimer 1993; van der Plicht 1993; Bronk Ramsey 1995; 2001; Buck et al. 1999).

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Figure 1.1: A section of the IntCal04 calibration curve (Reimer et al. 2004) to depict an example of the effect of the wiggles when calibrating dates. The position of two hypothetical, uncalibrated high-precision radiocarbon dates are marked as grey (Date One) and black (Date Two) triangles. A simple example of the effect of the wiggles in calibrating dates is illustrated in Figure 1.1, which shows a section of the IntCal04 calibration curve (Reimer et al. 2004) and the position of two hypothetical, uncalibrated high-precision radiocarbon dates (grey and black triangles). The earliest date (Date One), indicated by the grey triangle, occurs on a relatively flat section or plateau of the curve whereas Date Two (black triangle) is located on a fairly steep section of the curve. When calibrated, Date One returns an age range of 100 years at one sigma (one sigma states the 68% probability that measurement will be within one standard deviation of the mean; two sigma within two standard deviations (95%)),

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whereas Date Two returns a calibrated range of only ten years. Although the samples are only 100 14C years apart and have the same errors, the shape of the curve significantly affects their precision. The first radiocarbon date is effectively stretched across the length of the plateau, whereas the steepness of the slope has the opposite effect for Date Two. It is obvious from this example that a precise radiocarbon date does not necessarily provide a precise calibrated date, a point that will be discussed later in the text.

Age Limits and Accuracy The theoretical age limit of radiocarbon dating is in excess of the ability of current technology and technique. Such limiting factors result from a number of causes– environmental emissions, errors in counting, sample preparation and laboratory efficiency. As the age of the sample increases, the radiocarbon activity decreases. This decrease in activity increases the affect of external errors on the age determination. To counter this there has been a continuing effort to control contributing errors in order to push back the dating limits. Initially 14C dating limits were around 20,000 years, whereas theoretical limits of 70,000 years have been discussed for over a decade, using current counting techniques (Long and Kalin 1993). An age limit of approximately 50–55,000 years is now generally accepted. For AMS, theoretical limits of 70,000–100,000 years have been suggested (Muller et al. 1978), although blanks of geological graphite prepared under argon have so far reached a machine limit of around 70,000 years (Schmidt et al. 1987).

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What Can Be Measured? The usefulness of radiocarbon lies in the broad range of materials that can be dated using this method. Increasing technological advances in radiocarbon dating technology and sample preparation continue to widen its applications for the environmental archaeologist. At a basic level there only needs to be enough measurable 14C in a sample to use the technique. In some cases there will be abundant material suitable for dating that can be gathered easily; in others careful extraction techniques will be required to provide sufficient material even from a relatively large sample, such as a bone. Dating of archaeological material such as clothing, bone and wood is widely known, however, other materials such as mortar and iron have also been investigated for their usefulness as dating materials (Sonninen and Jungner 2001; Scharf et al. 2004). Certain items do come with caveats, for example, only the dentine in teeth is considered reliable for radiocarbon dating in archaeological contexts because carbonate in the enamel exchanges with the environment (Hedges et al. 1995). The wide range of materials that may be encountered within environmental archaeology can require the use of methods that are at the cutting edge of technique and technology. Improving chemical extraction methods can be used to separate specific molecules such as amino acids, or even DNA, from samples of bone and hair (Stafford et al. 1991; Burky et al. 1998; Spaulding et al. 2005) and microbial biomarkers from sediments and soils (Eglinton et al. 1997) for AMS dating. Microscopic plant remains such as pollen grains, used widely in reconstructing past environments, can often be concentrated into sufficient quantities for dating purposes (Brown et al. 1989; Richardson and Hall 1994; Mensing and Southon 1999). Techniques for chemically

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separating suitable material for dating insects, specifically beetles, are also currently being developed and tested (Hodgins et al. 2001; Tripp et al. 2004). 14C is also incorporated into the hard carbonate shells produced by many terrestrial and marine organisms thereby allowing these creatures to be radiocarbon dated. Although the potential list of usable materials is extensive, the contexts from which they have been derived need to be considered. Corrections often need to be made for cases where the uptake of 14C may not have been at atmospheric levels. Such differences can occur in the oceans (the marine reservoir effect), karstic areas or near sources of volcanic or hydrothermal outgassing (Rubin et al. 1987; Cook et al. 2001; Proskurowski et al. 2004), where very old carbon with 14C at very low activity levels is present in the environment and has been taken up by an organism. The old 14C will ‘dilute’ the atmospheric 14C thereby reducing the radioactivity of a sample and causing the radiocarbon age to be older than is actually the case (Goodfriend 1987).

Methodological Summary Sampling Ideally, strategies for sampling material for radiocarbon dating should be considered at the initial stages of planning an excavation or fieldwork. Radiocarbon dating is relatively expensive and limited understanding of the techniques, poor field practice, and a lack focus on the research/project questions can waste money and opportunities. However, the nature of archaeological excavation, especially on a commercial basis, can require decisions to be made quickly in the light of unexpected finds, external pressures from funders or developers, and limited time. This can often impact on the

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quality and the choice of samples taken. Poorly sampled material could very likely be contaminated, and give spurious results that have to be rejected or, more worryingly, form the basis for incorrect inferences. Sampled contexts should be secure; the contexts themselves should be such that they will provide useful information about the site or area, or the relationship between the material and the site. Again, the question should be asked of whether or not a date will necessarily provide useful information. To develop a detailed chronology for a site a sufficient number of samples are needed, ideally with clear stratigraphic relationships, so that Bayesian techniques, available in some calibration programs, can be applied to further constrain the calibrated ages (Buck et al. 1991). As such, the commissioning archaeologist may want to consider collaboration with a statistician or someone versed in these techniques (see Using the Dates below). As mentioned previously, dateable material can be influenced by its context, through old carbon, reuse of material, reworking of sediments, or even the inherent age due to the longevity of an organism such as a tree. Wood charcoal provides an example of the potential problems involved. The carbon taken in by a tree during growth is fixed in the growth ring for that year; charcoal derived from the centre of a tree may well be several hundred years older than the fire in which it was burnt. Reuse of older timbers in a structure in a conflagration will produce similar results, providing interesting, but undesired, dating problems. Wood and charcoal samples should be identified to species level so that ideally only short-lived species would be selected for dating purposes. The quantity of a sample to take is also important and will often be dictated by how much there is and on the requirements of the technique that will be used to provide the

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date. The amount of carbon in a sample varies with the type of material and sample preservation, which can be problematic for bones in particular. Before planning a sampling scheme around bone, it might be worthwhile to send a typical sample in to the laboratory to test for protein preservation in the sample. Table 1.1 provides details of the amounts required for some of the materials the Belfast Radiocarbon Laboratory handles for high precision LSC dating and AMS dating. The estimated precision for a single sample c. 5000 years old is approximately ± 20 years and ± 35 years, for LSC and AMS dating respectively. The current AMS dating targets prepared at Belfast require 1.2 mg of carbon after pre-treatment although a new graphite line is currently under construction that will enable target preparation using sub-milligram quantities of carbon. M a t e r i al

High P recision

AM S

Wood

150 g

10 mg

Bone*

600 g

600 mg

Antler*

600 g

600 mg

Cremated bone

Not done

1.5 g

Charcoal

40 g

5-10 mg

Peat

250 g

10 mg

Cloth

120 g

10 mg

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Humus Soil**

1200 g

100 mg

Shell

110 g

20 mg

Silt**

2000 g

200 mg

Table 1.1: Suggested minimum weights for high precision liquid scintillation radiometric and AMS radiocarbon dates. * = If collagen has been sufficiently preserved in the bone or antler. ** = Depending on % carbon.

Handling and Storage The importance of the appropriate handling and storage of radiocarbon samples cannot be overstated. Potential for contamination is present at each stage and will affect the accuracy of any dates produced. The introduction of carbon to a sample needs to be avoided at all costs. Although treatment in the laboratory can remove many contaminants, the introduction of new ones will produce errors in addition to those that cannot be avoided. Contamination can occur at several stages as the samples progress through the dating process. Poor sampling in the field using dirty tools, the mixing of contexts or a lack of care whilst containing and storing the material will seriously affect results. Careful cleaning of tools between sample collection should always be carried out. The choice of a suitable container for the sample needs to be thought through before sampling takes place–even paper labels placed within sample bags can be a potential source of contaminating carbon. Extended storage of

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sediment samples can also be problematic, allowing fungal and bacterial growth to take place and potentially introduce contamination (Wohlfarth et al. 1998). For many samples, such as wood or bone, simply rinsing the material in distilled water and drying in a low temperature oven will prevent mould and fungal growth. These sources of error may be compounded by those that can be introduced during the laboratory cycle. Very high standards are required to reduce the risk of further contamination at this stage, especially when dealing with very small samples. Although seldom encountered in archaeological field sites, laboratory and storage facilities where 14C has been used in tracer experiments can seriously compromise the results (Buchholz et al. 2000). In high precision laboratories, such as that at Belfast, sources of error are accounted for in a constant effort to maintain and improve dating standards.

Submitting Samples There is a choice of laboratories that can be used by the archaeologist when submitting a sample for radiocarbon dating offering different facilities, services, and accuracy, and the associated costs will vary accordingly. Most laboratories will offer perfectly adequate results for most archaeological situations. If one is interested in the general chronology of a site then extreme accuracy and precision will not be worth the extra cost. When the archaeologist needs to differentiate between or date contexts to within a few decades, however, only a few high precision laboratories will be able to carry out suitable measurements–Belfast being one. Laboratories may use an estimated 13C/12C ratio of the sample (reported as δ13C relative to the Vienna PeeDee Belemnite (VPDB)

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standard) for the fractionation correction, although many laboratories routinely include a δ13C measurement either as part of the price of the date or for a small additional charge. Measurement of the 13C/12C ratio of the sample will give a more precise result, especially if the natural variability of the material is large or must also be estimated. The required measurement precision may also be determined by considering the effect of the calibration curve at the expected time period for the date. A radiocarbon age that falls on a plateau in the calibration curve will result in an imprecise calibrated age (see Figure 1.1), no matter how precisely the sample is radiocarbon dated (Guilderson et al. 2005). In addition to precision, sample size may dictate the technique required, i.e. radiometric or AMS dating, and so the choice of laboratory. The small sample size required and relatively short time involved should make AMS the favourite choice, although there are issues to be considered. Some GPC and high precision LSC systems offer greater precision for single samples than most AMS systems. Sampling can become more problematic when taking only very small samples or samples of very small things. Small samples may come from a non-representative section of the sampled item and some, such as pollen grains, may well be more mobile than the context they are in, thereby causing a higher probability of producing ‘unhelpful’ dates. On the other hand, the dating of identifiable plant remains, especially fragile macrofossils such as leaves, can provide assurance that the samples have not been transported a long distance before deposition. When only small samples, or samples with only very small amounts of datable material in them, are available AMS may well be the only method with which to achieve a date.

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Using the Dates Even before the date has been produced by the laboratory the archaeologist should think about how it is to be used and published. The raw radiocarbon age is not equivalent to a calendar date because the 14C in the major carbon reservoirs has not been constant as is assumed in the calculation of the raw radiocarbon age (see Calibration above). These radiocarbon years can meaningfully be compared against each other, but if one wants to compare the results against an historic event or against dates produced using another dating method such as dendrochronology or uranium-thorium dating then the date will need to be calibrated. Presentation of the dates is also important and as much information about the date should be provided as possible. Simply publishing a calibrated date will not show how the date was produced, which calibration data was used, which laboratory produced the date and what error margins are associated with the laboratory measurement. Raw dates and the uncertainty at one sigma along with the unique laboratory identification code given to each submission should always be made available so that others can reproduce the calibrated date or update it if new calibration data becomes available e.g. 1234 ± 56 (UB789). The laboratory identification code is unique and allows the measurement to be traced back to the original submission. If an author wishes to use the calibrated rather than raw date in a text this should be made clear and the raw date made available elsewhere in the publication, linked by the laboratory code. Measured or estimated δ13C (see Fractionation Correction above) should also be reported if available together with any reservoir corrections used, these

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can be placed in an appendix and linked to the date through the laboratory code. Standardisation for presenting radiocarbon dates has been discussed for over 20 years but there remains inertia about wider implementation by the archaeological community (Stuiver and Polach 1977). Calibrated age ranges (one and/or two sigma) should also be given, in most cases, with a reference to the calibration curve used. The two sigma calibrated age ranges are generally preferred because these include 95% of the calibrated probability distribution. The calibrated age ranges can be presented as the minimum and maximum calibrated ages–e.g. 2340–1890 cal. BC–or multiple ranges may be given–e.g. 2340–2280 cal. BC and 2010–1890 cal. BC) accompanied by the probability associated with each range as shown in Table 1.2.

Table 1.2: Suggested reporting of two sigma (2 σ) calibrated radiocarbon ages and relative probabilities. There is a temptation to present the midpoint of the calibrated age ranges with a symmetric uncertainty but this oversimplification is a misrepresentation of the calibrated probability distribution (Telford et al. 2004). However, simple calibrated age-depth plots using the midpoint of the calibrated age range or other single estimator have often been 64

used successfully in palaeoenvironmental studies due to a lack of more sophisticated tools at the time. For example, Weir (1995) used simple calibrated age-depth plots of radiocarbon ages and tephra dates to suggest an ‘Iron Age hiatus’ in agricultural activity between 200 BC and AD 200 based on pollen sequences from two former lake sites (Essexford Lough and Whiterath Bog) and a raised bog (Redbog) in County Louth. Because stratigraphic information or other dating evidence is often available in palaeoenvironmental sequences, including this information in a statistical framework using Bayes Theorem (Bayes 1763) can help refine the chronology. The Bayesian Theory has been adapted for use with radiocarbon data (Buck et al. 1991; Christen 1994) and made available in the computer programs BCal and OxCal (Bronk Ramsey 1995; 2001; Buck et al. 1999). These programs have been widely used by archaeologists to construct and test chronological models, such as for the re-evaluation of the chronology of Stonehenge (Bayliss et al. 1997), the sequence of construction and destruction of Navan Fort, Co. Armagh (Gault 2002) and the timing of the volcanic destruction of the Minoan Civilization (Manning et al. 2006). Although not as widely used in environmental sequences, there has been a great deal of interest in the adaptation of Bayesian techniques to sedimentary processes in order to construct calibrated age-depth models (Bennett 2005; Blaauw and Christen 2005; Bronk Ramsey in press; Millard and Brooks in prep.). When a sequence of samples with known calendar spacing can be radiocarbon dated, such as tree-rings in a timber or log, then the shape of the calibration curve can be used to improve the resolution of the calibrated age range. This

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process, known as ‘wiggle-matching’, can be applied using classical statistical methods (Pearson 1986) or with Bayesian statistical methods where it is known as a defined sequence. Examples of the use of ‘wiggle-matching’ in archaeology are the refinement of the construction dates for the royal tombs of Pazyryk, south Siberia (Mallory et al. 2002), and in the confirmation of the dendrochronological result for the Seahenge timber circle (Bayliss et al. 1999). ‘Wiggle-matching’ can also be applied to peat sequences if an assumption about the growth rate of the peat is made. Pilcher et al. (1995) used this technique to provide a calendar age estimate of the Hekla 3 Icelandic tephra and Plunkett (1999) established a date for the Hekla 3 event based on the position of the tephra between other well-dated events in a profile from Claraghmore Bog, Co. Tyrone. Both of these tephras are widely used as time-stratigraphic markers in Ireland.

Conclusion Radiocarbon dating continues to be of major importance to the archaeological community. Although other dating techniques, such as dendrochronology, thermoluminescence (TL), optically stimulated luminescence (OSL), and uranium-thorium, are available for some types of samples only radiocarbon has the breadth of application required to answer many archaeological problems. The well-tested calibration curve for the Holocene period provides radiocarbon dating with an accuracy that only dendrochronology can surpass when suitable material is available. For the environmental archaeologist, radiocarbon dating is an essential tool by which the interactions between human activity and the environment can be interrogated. Closer working relationships between the environmental archaeologist and radiocarbon laboratory personnel in 66

exchanging ideas and advice at the outset of a project will aid in sample selection and interpretation of results. Improvements in AMS technology and sample preparation techniques look certain to increase the precision and application of this technique as a dating tool, while inter-laboratory comparisons and analysis of known age material improve accuracy. The efforts by the laboratory in Belfast and many other laboratories continue to increase the accuracy of the calibration curve during and before the Holocene and to extend the calibration curve back to 50–55 ka. Work in the Southern Hemisphere is providing opportunities for archaeologists to calibrate dates to an accuracy and robustness that has previously only been available in the Northern Hemisphere. Online resources are providing access to sophisticated dating tools and archives (see below) of existing archaeological dates from Britain and Ireland and beyond. Although radiocarbon has had a short history in relation to many other aspects of archaeology and environmental studies its impact has been dramatic and continues to be vital for the progress of ideas and practice.

Online Archive Sources http://ads.ahds.ac.uk/catalogue/specColl/c14_cba/ http://www.historic-scotland.gov.uk/ wwd_carbondatingsearch http://www.canadianarchaeology.ca/ http://bcal.shef.ac.uk/ http://calib.qub.ac.uk/calib/ http://c14.arch.ox.ac.uk/oxcal.OxCalPlot.html

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Stuiver, M. and Polach, H. A. 1977. Reporting of 14C data. Radiocarbon 19, 355–63. Stuiver, M. and Reimer, P. J. 1993. Extended C-14 data-base and revised CALIB 3.0 C-14 age calibration program. Radiocarbon 35, 215–30. Stuiver, M., Braziunas, T. F., Becker, B. and Kromer, B. 1991. Climatic, solar, oceanic, and geomagnetic influences on Late-Glacial and Holocene atmospheric C-14/C-12 change. Quaternary Research 35, 1–24. Suess, H. E. 1955. Radiocarbon concentration in modern wood. Science 122, 415–17. Telford, R. J., Heegaard, E. and Birks, H. J. B. 2004. The intercept is a poor estimate of a calibrated radiocarbon age. The Holocene 14, 296–8. Tripp, J. A., Higham, T. F. G. and Hedges, R. E. M. 2004. A pretreatment procedure for the AMS radiocarbon dating of sub-fossil insect remains. Radiocarbon 46, 147–54. van der Plicht, J. 1993. The Groningen Radiocarbon Calibration Program. Radiocarbon 35, 231–7. Vogel, J. S., Ognibene, T., Palmblad, M. and Reimer, P. 2004. Counting statistics and ion interval density in AMS. Radiocarbon 46, 1103–9. Weir, D. A. 1995. A palynological study of landscape and agricultural development in County Louth from the second millennium BC to the first millennium AD. Final report. Discovery Programme Reports 2, 77–126.

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Wohlfarth, B., Skog, G., Possnert, G. and Holmquist, B. 1998. Pitfalls in the AMS radiocarbon-dating of terrestrial macrofossils. Journal of Quaternary Science 13, 137–45.

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2 Dendrochronology and Lessons Learned from Irish Examples David M. Brown and Mike G. L. Baillie

Abstract The increasing number of sites and artefacts being dated by dendrochronology highlights the success rates with which this technique can be applied in Irish wetland archaeological situations. Completeness of samples with respect to sapwood (the outer band of rings below the bark which represent the last years of the tree’s life) is the limiting factor for dating precision and subsequent archaeological interpretation. Examples of the dating method and its associated limitations are discussed.

Introduction When archaeologists supported the construction of an oak chronology in Ireland, the exercise was primarily aimed at the calibration of the radiocarbon time-scale. If a long chronology could be constructed by overlapping the annual ring patterns of Irish oaks with those of timbers of the same species from Medieval buildings, from archaeological sites and from natural, mostly bog, sources, then a standard chronology would exist against which radiocarbon could be tested. In fact, what happened was that between 1970 and the

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mid-1980s a year-by-year oak chronology was constructed in Ireland which extended back to 5289 BC (Pilcher et al. 1984). The chronology was continuous and precisely dated so that samples of exactly known calendar age could be supplied to radiocarbon laboratories. Moreover, the oak chronology was replicated by step-wise comparisons from Ireland through to England to parallel, independent, oak chronologies in Germany. Thus, by 1986 there existed not only a replicated tree-ring chronology, but a definitive Irish radiocarbon calibration curve dating back to 5200 BC that could be used to convert radiocarbon dates from Irish sites and deposits to estimates of real age (Pearson et al. 1986). It is worth remembering that the calibration curve is, by definition, precisely dated, so that it is possible to view changes in the atmospheric concentration of radiocarbon at any point in the last seven millennia. By the time the calibration results were published, it was already known that the oak chronology could be used to directly date any long-lived oak specimens that were obtained from natural bog or lake contexts, or from archaeological sites and buildings. Thus, for the last two decades a list of well-dated archaeological sites and artefacts has been developed in the Palaeoecology Centre, Queen’s University Belfast (Fig. 2.1).

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Figure 2.1: Cumulative plots of the numbers of tree-ring dated Irish archaeological sites through time. The discontinuous nature of the distribution is apparent. In this chapter we wish to look in a little detail at the dating process and at how even dendrochronological dates have to be interpreted depending on the completeness of the samples. We will review issues concerning the importance of sapwood and how it is the limiting factor when it comes to answering questions about cause and effect in the past. We will draw the distinction between the issue of dating an individual site and the patterns of dates arrived at when numerous site dates are combined, as in Figure 2.1. As should be obvious from Figure 2.1, the dates are not random but are bunched in time, with clear construction episodes separated by long periods from which few or no archaeological oak timbers appear to survive. Alongside this picture of human activity in the past Irish landscape, some efforts have been made to understand

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environmental information contained in the tree-ring records. In combining these different lines of enquiry we have been privy to the first clear glimpse of what may have been going on in the Irish past, at high chronological resolution.

Practicalities of Dendrochronology It is fair to say that dendrochronology only seems easy in theory. The method has to be kept under some rigorous control otherwise unreliable results may start ‘leaking’ into the literature. Perhaps the simplest way to explain this process is to start by outlining an ideal dating situation and then working down from there. Imagine we are working in a small area such as the north of Ireland. Within that area we can expect the oak tree-ring signal–that is, the signal to which most of the oaks growing in the area are attempting to respond–to be fairly uniform. If we take a selection of oaks from different sites within the north of Ireland and build a master chronology, that chronology is highly ‘stable’. The easiest way to demonstrate what is meant by ‘stable’ is to repeat the exercise. Thus, we can take another fresh selection of oaks and build a new oak chronology for the same general area. We have done this and the result is two totally independent master patterns that are as similar in terms of year-by-year detail as to be effectively identical. In scientific terms this means, in our ideal situation, that we work in an area where it is possible to saturate the signal–i.e. there is only one master signal producing one master chronology and it is a fair reflection of what an average oak was doing in terms of year-by-year growth. One obvious question is whether this chronology is ideal, adequate, inadequate, or even useless, for the whole island of Ireland. Here we have to fall back on empirical evidence. We know

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that for many periods we can date oak timbers from anywhere in Ireland with a high degree of reliability. However, there seem to be other periods when this ideal situation breaks down. These could be periods when the master chronology is not very well replicated, or where all the sites in the chronology tend to come from a small area (for an example of this, see Baillie and Brown 1991; 1998), or where some alteration in climate means that different parts of the island are temporarily in different zones as far as the tree-ring signal is concerned. There are other potentially compounding factors; for example, the differences between bog-grown and land-grown timbers. Most of the prehistoric chronology was constructed of bog oaks that had grown on the surfaces of peat bogs. These trees are somewhat different in their growth response from land-grown timbers that have been preserved on archaeological sites. Figure 2.2 shows a section of pure Irish bog oak chronology plotted against a section of archaeological oak chronology. While the curves are very similar, there are some notable differences. This observation implies that on some occasions it may prove difficult to date sections of archaeological chronology against a pure bog-oak chronology, especially if there is a significant distance factor involved. A good example of this would be the first Corlea track to be dated (Raftery 1990). Initially, only one oak timber was available from this Co. Longford site and it failed to date against the Belfast (northern) master chronology. However, as soon as even four Corlea ring patterns were averaged together the resultant Corlea site chronology cross-matched immediately against the Belfast master at 148 BC.

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This latter point brings out the difference between single ring patterns and replicated site-master chronologies. By averaging several individual ring patterns together from a single site we move the signal away from the single tree situation and closer to the saturated master described above. There is no exact rule concerning how many timbers have to be averaged together to ensure that a site chronology will date against a master chronology. Experience suggests that a mean chronology of three or more timbers, however, will stand a good chance of dating successfully. One reason for the rather tentative nature of these statements is that there are other factors that need to be taken into account. One critical issue is chronology length. There is no doubt, in our experience, that individual ring patterns and even site masters must have 100 rings or more to stand a reasonable chance of successful, and reliable, dating. Workers elsewhere have different experiences but in Ireland we would advise extreme caution when trying to date any short ring patterns.

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Figure 2.2: Although the year-to-year detail in bog oak and archaeological chronologies is very similar, it is clear that in this mid-twelfth century episode bog-oak growth was more severely affected. We can summarise the above by saying that where multiple, long, ring patterns can be built up into site chronologies, or where very long (say >150 years) individual tree-ring patterns are available then there is a high probability of successfully cross-dating material against the available master chronologies in Ireland. This has been particularly well demonstrated by the high level of success in dating trackways and other wetland structures from the Bronze and Iron Ages.

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Moving From General to Specific Issues We have indicated that oak ring patterns can be dated with a high degree of success in Ireland (indeed the same can be demonstrated across northern Europe). However, establishing the exact calendar dates of every ring in a tree-ring pattern is not the same as providing a useful date for an archaeologist, building historian or palaeoecologist. This is because of a fundamental issue in dendrochronology, namely, that the most useful date that a dendrochronologist can produce is the date of the final growth ring–the death date. Whether it is the construction date of an archaeological site, the date of the storm that blew down a bog oak, or the date of the rise in water level that killed a lake-side pine, the only date that allows proper interpretation is the death date of the tree. This brings us to the issue of sapwood. Many tree species have a clearly visible band of rings immediately below the bark, called the sapwood to distinguish it from the inert and usually darker coloured heartwood. The presence of living cells in the sapwood allows it to be distinguished from the inner heartwood. In any dendrochronological exercise, the presence of complete sapwood allows the researcher to establish an absolutely precise calendar record of events via the study of dates associated with the death of trees. In real life situations, timbers preserved under various conditions will have suffered various amounts of sapwood loss; in extreme cases, heartwood rings will also be missing through rot or woodworking practises. These situations, where samples are effectively incomplete, mean that many dendrochronological dates have associated errors because an allowance for missing sapwood has to be added to the date of the last existing ring. In extreme cases, where there is no

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evidence for sapwood on a sample, the dendrochronologist is forced to add a sapwood allowance together with a cautionary statement that ‘the actual felling date may be in or after the estimated felling range’. In such cases, the dendrochronological date serves only to provide a terminus post date. The dendrochronologist may be able to give the exact calendar date of the last existing growth ring, but that date could be years, decades, or in extreme cases, centuries prior to the actual death date of the tree. Since it is the death date that is important when examining archaeological or environmental activity, these terminus post dates come a very poor second to the exact dates conferred by samples with complete sapwood. It is therefore beholden on anyone wanting tree-ring dates to try, as far as possible, to acquire samples with their sapwood intact.

Sapwood Estimation and Preservation The early tree-ring work at Belfast included measurement of the number of sapwood rings on a range of oak samples. The mean value obtained for Irish oak was 32 ± 9 rings (at one standard deviation, 32 ± 18 at two standard deviations); no evidence exists that this range needs to be altered, although it is now known that the number of sapwood rings varies considerably across Europe (Hillam et al. 1987). In addition to estimating sapwood ring numbers, the early work also proposed that, depending on sapwood presence/absence, several different qualities of dendrochronological dates can be envisaged. These are: Type A–Where complete sapwood is present and a ‘death date’ can be given.

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Type B–Where some trace of sapwood is present and the addition of a sapwood allowance onto the date of the last heartwood ring provides a good estimate of felling range. Type C–Where there is no trace of sapwood, heartwood rings may be missing and a terminus post date as noted above is provided. Because dendrochronologists have always advised archaeologists that complete sapwood is needed to obtain a precise felling date for an oak sample, wetland archaeologists have provided almost ideal samples for studying issues related to sapwood preservation. Recent examination of samples with sapwood has provided some interesting statistics.

Table 2.1: The numbers of grouped archaeological sites from the prehistoric period with a breakdown of the types of dating quality as indicated by complete sapwood (Type A), some sapwood (Type B) and no sapwood (Type C). If we look at the period from around 1500 BC to around 100 BC, the Palaeoecology Centre has dated oak timbers from about 65 archaeological sites; as shown in Figure 2.1, these cluster into clear groupings through time. For the group of sites c. 1600–1400 BC there are 22 phases of activity evident from 21 sites. From these phases, only five sites provided

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samples with complete sapwood; 11 sites provided timbers with some sapwood, or the heartwood-sapwood boundary, present; six sites provided timbers with no sapwood present, including some with heartwood rings missing. So, almost one third of Middle Bronze Age sites produced samples that provided the poorest quality, Type C, dating; less than one quarter produced ideal dating. Equivalent numbers for the Later Bronze Age and Iron Age groups of sites are provided in Table 2.1. Given the fact that many archaeologists know the importance of sapwood, and should hence have been trying to maximize the number of samples with complete sapwood, it is possible to use the information in Table 2.1 to speculate on whether woodworking practises had changed through time or if sites of some periods were exposed to the elements for longer periods before being buried in wetland contexts. For example, how else might we explain the larger number of samples from the c. 1200–900 BC grouping that exhibit no sapwood, as compared with the c. 1600–1400 BC group? Referring to Table 2.1, we would have expected, considering the good conditions for preservation in Irish peat bogs, that we might have observed a greater proportion of samples with sapwood. In some ways this presents a rather depressing picture. It is important to recognise that dendrochronological dating raises expectations; archaeologists are expecting calendar dates from dendrochronological exercises; palaeoecologists are also expecting to be able to answer questions at calendar resolution. For example, in the tenth century BC we would want to know if there were more discrete episodes of construction activity within the century, i.e. we are asking questions that require mostly Type A dates. We want to know if the building activity is responsive to a

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changing environment, as possibly reflected in short-term environmental changes deduced from both tree-ring patterns and archaeological information. Unfortunately, with only one fifth of sites producing actual felling dates, the question cannot be answered, even though at face value we have 28 tree-ring dated sites for study. Interestingly, if we look at dates for a set of Early Christian period horizontal mills we tend to get a slightly better preservation of sapwood. Out of the 32 sites dated, eight have complete sapwood and produce Type A dates, while seventeen produce Type B dates. Overall, it seems that if archaeologists want answers involving real dating precision, they need to push up the proportion of samples capable of giving Type A dates. Unfortunately, because even Type B and C dates seem adequate in most archaeological contexts (because they are better than most other available dating methods) most archaeologists are satisfied with such dates at a site level. However, when larger questions are posed involving archaeological activity in the context of precisely-dated environmental change, or regional site construction, the problems and inadequacy of Type B and C dates become fully evident. In other words, archaeologists must always strive to get the best and most refined dates possible if their sites are ever to fit into the world of real chronology that is currently being developed by dendrochronologists and ice-core workers, among others.

Late and Post Medieval House Structures and Sequences Recently Brown (2002) has published a complete list of Irish buildings that have provided dendrochronological dates. In these later periods, we can look at some examples of sites in

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which the timbers have complete sapwood present on most, or all, of the samples. We can contrast relatively simple wood exploitation in some structures with more complex use patterns in others. A good example of this contrast in the Post Medieval period would be to compare results on timbers from Rathfarnham Castle, Dublin, with those from Cultra House, Co. Down.

Rathfarnham Castle, Dublin From documentary evidence, it was believed that Archbishop Loftus, having acquired the land forfeited to the crown in the 1570s by the rebellion of James Eustace (Viscount Baltinglass), built a massive castle at Rathfarnham in the 1580s; most likely in 1583. In 1996, the then Office of Public Works requested that a dendrochronological exercise should be carried out on the roof timbers from the castle. As a result of the request, nine oak timbers from the roof and three other timbers from floor joists at Rathfarnham Castle were cored (hollow tubular drills are used to extract pencil sized cores and these ring records are supplemented where possible with overlapping sections cut through surviving sapwood). Two sash pulleys were also made available for examination. While the primary reason for this exercise was to test the historical record, it needs to be remembered that dendrochronological dating, despite the comments about Type A dating above, does not give the actual building date for a structure; it merely gives the felling or death date closest to the building date. Thus there is no expectation that dendrochronology, even on complete samples, will yield the documentary date. Timbers have to be transported and could

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be stockpiled for building; even seasoning may occur. As a result, the expectation is that dendrochronological dates falling in the few years before the documentary target date would be acceptable evidence that the historical documentation was broadly correct. However, so refined is this type of dating that it is necessary to give even more detail. All the timbers sampled from Rathfarnham Castle were oak, Quercus robur or Quercus petraea. This species of tree is ring porous and in transverse section exhibits large spring vessels at the start of the year’s growth, with much smaller vessels and thick walled fibres later in the growing season. Leaf opening is at the end of April but the bulk of early-wood synthesis is in May; summer growth is finer-celled, represented by small summer vessels (Baillie 1982). Thus, when a sample has complete sapwood present the final ring can be examined to see how much annual ring growth had taken place before the tree was felled, i.e. some suggestion of ‘season’ is possible with complete samples. If only the spring vessels are complete, felling is in the early summer of that year. If the ring appears complete with both spring vessels and summer wood, then felling will have been later in that year or early in the following year.

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Table 2.2: Details of the individual samples from Rathfarnham Castle, Dublin. The letters after the number of rings indicate if the dating was of Type A, B or C. Of the 12 samples taken from the main timbers at Rathfarnham, eight had complete sapwood; two had some sapwood present, while two had neither sapwood nor the heartwood-sapwood boundary present. With eight of the 12 samples providing complete sapwood a study can be made of the probable season when the trees were felled, see Table 2.2. For the eight samples with complete sapwood, a remarkably consistent picture emerges. All eight were felled in the year from early summer 1583 to spring 1584 at the latest. However, it is most likely that they were felled in the period bracketed by early summer to autumn 1583, given that they represent a population intended for use in a prestige building. The other samples are not inconsistent with the 1583 dating. For example, the last existing ring in Sample Q9182 grew in 94

the year 1581. As the last ring could not be identified as the final ring under the bark, a sapwood allowance has to be added to the date of the last heartwood ring. This produces a date range of 1594 ± 9 years. However, detailed examination of the sample indicates that in reality only the outer few rings of sapwood are damaged and it is reasonable to suggest that felling was probably consistent with the main 1583 phase. Just to labour the issue of interpretation, Sample Q9179 has sapwood out to the year 1561 but it appears incomplete. The best estimate of the felling range for this sample can be stated as ‘1563 ± 9 but definitely after 1561’. This may seem sufficiently prior to the target date of 1583 to suggest that this was a re-used timber. However, we would caution that the one standard deviation (± 9, giving a 68% probability) value for Irish oak sapwood is a statistical estimate that will only be correct two thirds of the time. If we apply the more reliable two standard deviation range of ± 18 years (giving 95% probability), then the estimated felling range extends to 1581 suggesting that this sample may in fact be part of the c. 1583 assemblage. Sample Q9187 represents Type C dating where it is likely that heartwood rings have been removed during woodworking. Thus, its seemingly early date range of ‘1544 ± 9 or later’ could easily be explained as the result of woodworking rather than re-use of a genuine older timber. Overall, a perfectly reasonable interpretation of this group of samples is that they are all part of the original group of trees felled to build Rathfarnham Castle. The complete samples allow us to propose that the trees were felled in the six months after April 1583 or just possibly into early 1584. As seasoning is not believed to be a serious issue for building timbers in Ireland in the Later Middle Ages, it is likely that

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the house was indeed built in 1583 or 1584. The very fact that so many of the timbers retain their sapwood is suggestive that the timbers were not seasoned as this would probably have contributed to sapwood degradation or loss. This then allows an additional refinement. By viewing the correlation values of the Rathfarnham ring patterns against a range of Irish regional master chronologies it is possible to attempt some localisation of the timber source. When this was done, it appeared most likely that the bulk of the trees were collected from in and around the Dublin area. However, there is just a hint in some correlations involving Samples Q9184M, Q9186 and Q9187 that they may have been collected from an area closer to Belfast than Dublin. Such indications are suggestive rather than definitive, though experience shows remarkable consistency in location exercises (Baillie 1995a).

Cultra House, Co. Down We can compare the excellent single-phase dating at Rathfarnham with another exercise carried out at Cultra House, Co. Down. In this case, the Historic Monuments and Buildings Branch of the Environment and Heritage Service for Northern Ireland, Department of the Environment, requested a dendrochronological study to be carried out on the roof of the house. In this case ten timbers were available for sampling (Table 2.3). In this exercise, seven of the ten samples had sapwood present, with four having complete sapwood. This should have provided sufficiently tight chronological information to confirm the dating of the roof structure from this house. 96

However, the results indicated a more complex building history than anticipated. The results provided in Table 2.3 indicate the problems associated with any attempt to interpret the building history of Cultra House. Firstly, two of the potential Type A timbers, Q8875 and Q8878, contained too few growth rings to provide definitive dates. This reduced the number of samples with definitive end dates to two. One of these, Q8873, was felled in the early summer of 1670. In contrast, the last ring on Q8880 had complete spring and summer wood and was felled in either late 1666 or early 1667. This inconsistency was further compounded by the observation that the timbers with Type B dates were scattered across an extended period, ranging from the late sixteenth to the late seventeenth century. Additional evidence from the timbers indicated mortice holes and other woodworking details that were redundant to the contexts where the timbers were found, something that could be consistent with timbers having been re-used. Indeed, examination of the Ordnance Survey map for the area indicated a complete change in the orientation of the house between the production of the mid-nineteenth century map and the 1930s map. This observation raised the spectre that the roof had been dismantled and re-constructed using material from more than one source or phase.

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Table 2.3: Detail of the individual samples from Cultra House, Co. Down. The letters after the number of rings indicate if the dating was of Type A, B or C. In contrast with Rathfarnham, where a highly consistent set of dates were in good agreement with known historical documentation, the situation at Cultra, despite the fact that eight timbers could be dated by dendrochronology, is disappointing. The best that can be said is that the Cultra roof appears to contain a group of timbers (namely Q8873, Q8877, Q8879 and Q8880) felled in the vicinity of 1670. If this was the original building phase then it may have contained at least some re-used timbers and, in addition, there is a possible hint of later activity in the form of Sample Q8881 (though even here it has to be remembered that this sample could have been felled as early as 1671). The limitation imposed on interpretation by incomplete tree-ring samples is well illustrated by this example. As noted, there is no actual guarantee that the roof, as observed, originally belonged to Cultra House at all.

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Early Christian Examples: Nendrum Tidal Mill and Island MacHugh Crannog The Nendrum tidal mill in Strangford Lough, Co. Down (McErlean and Crothers 2001), offers a further insight into timber dating. Recent excavations at the site have produced a series of timbers relating to the mill structure and an accompanying revetment that was used to capture the water to run the mill at low tide. In total, 27 samples were submitted for dating. This included no less than 18 samples with complete sapwood; unusual by most standards, as detailed above. Archaeologically, the mill complex has three clear, well separated, phases. However, virtually all the timber samples turn out to be from the initial phase of construction. In this case detailed examination of the dates shows that three samples were felled either late in AD 618 or early in 619, and no less than six timbers were felled in the early summer of 619. This is suggestive that either the initial pulse of building activity was undertaken in the spring or early summer of 619, or that this represented the first accumulation of timbers for subsequent building. Felling activity then continued with another three timbers felled either late in 619 or early in 620, and a further three felled in either late 620 or early 621. The question raised by this spread of dates is whether building was spread through time or whether timbers were stockpiled from 618/619 for use in construction in 620/621. This is compounded by the observation that a number of the timbers had mortise holes with no obvious functionality. While the excavator interpreted these mortises as being due to the re-use of timbers, both the dates, and the pristine nature of the sapwood, argue against re-use (mortises towards the ends of heavy timbers may have been simply to assist with transport).

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While the issue of stockpiling timbers or extended building may sound esoteric, we appear to see the beginnings of such a pattern in the early seventh century. At Island MacHugh Crannog, Co. Tyrone, palisade oak posts, with complete sapwood, indicated felling in at least seven separate episodes from AD 601 to 619 (specifically 601, 602, 603, 608, 611, 614 and 619)–a period assumed too long to be simply due to stockpiling (Baillie 1993). In fact, the long distribution of dates from the site raises questions about the date of a site such as Island MacHugh–is it AD 601 when activity began, is it 610, the mean date of the activity, or is it 601–619, the identifiable period of activity? This is a type of problem not normally encountered by archaeologists. However, the reason for detailing the issue is that Crone (2000) has observed exactly comparable activity at Buiston Crannog in Scotland. In that case building activity started in AD 550, interestingly close to the date of the earliest Ulster crannogs that were constructed from around AD 550 onwards (Baillie 1982). There then followed major felling phases for palisade construction and refurbishment in 594, 608, 613, 614, 615, 616, 620, 629 etc. Crone recognises the difficulty in interpreting such dates and, as part of a complex set of arguments, notes:

‘Where all the dated sequences were felled in the same year and there is no spread of dates, we may assume that the felling date reflects the construction date. However, where there is only a single sequence with bark edge providing the felling date, we cannot know whether this represents the actual construction

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date or one of the years in which timber for stockpiling was felled, construction taking place some time afterwards’ (Crone 2000, 54). Taking Crone’s argument at face value, we could toy with the idea that the Nendrum mill and revetment was actually constructed in the winter of AD 620 or the spring of 621; after all, is there any point in partially constructing a mill? However, the main point is that more thought is necessary on issues relating to tight chronology and how to interpret sets of data such as these. What is important is the observation that complete sapwood offers up a whole new realm of chronological detail for investigation.

Wider Considerations The story of the construction of the Irish oak master chronology has been detailed elsewhere (Baillie 1982; 1995a). Suffice to say that large numbers of samples (of the order of 10,000) were accumulated from a wide variety of natural and archaeological contexts over some three decades. As a result of that effort we can look at quite a range of factors involving the past that have never previously been available. As indicated in Figure 2.1, we now have some measure of the distribution of archaeological oaks through time. We can parallel that observation with the results of the dating of an extensive, near-random, collection of bog oaks–trees which grew on bog surfaces and were preserved buried in the peat. If we look at a plot of the frequency of these naturally preserved trees it is apparent that there were periods from which trees survive in quite large numbers separated by other periods when bog oaks were relatively 101

scarce. Figure 2.3 shows the overall bog oak distribution for Ireland. We can also speculate why this pattern might exist (Baillie and Brown 1996). The important aspect from an environmental archaeological perspective is that all the information is precisely dated. Thus, for the first time, we can see certain hints of at least some aspects of what was happening in the Irish past in real time. In addition, because of the vast amount of effort put into radiocarbon chronology by archaeologists in Ireland we can make some moves towards integrating the two records. Thus, we know from calibrated radiocarbon assay that the Neolithic started/arrived in the period 4000–3800 cal. BC, while the Bronze Age starts roughly in 2500–2300 cal. BC. We can now view cultural change against a backdrop of both archaeological dates and some environmental information.

Figure 2.3: A frequency distribution of Irish bog oaks through time. The distribution of lake edge pines (P) is shown for comparison.

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Table 2.4: Provisional list of notable prehistoric dates from the various strands of tree-ring evidence. In addition to these sources, there are other dates that have come directly from analysis of the tree-ring chronologies themselves, several of which have given rise to some level of debate. These include the so-called ‘narrowest-ring events’ that appear as episodes of very unpleasant growth conditions for bog oaks in Ireland. These are extreme events in the sense that at least some of them show up in other records outside Ireland hinting at global environmental downturns (Baillie and Munro 1988; Baillie 1995a). The concept that global events could influence populations in Ireland takes a little getting used to. However, once it is realised that any major dust-veil event can affect the environment of most of the planet by placing a veil of material between the Sun and the Earth’s surface (whether it is caused by explosive volcanism or by extraterrestrial loading of the atmosphere as a result of

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impacting space debris), it is not so surprising that from time to time Irish trees and Irish human populations were adversely affected by global environmental downturns. To elaborate, it is now possible to imagine dust-veil events that would cause several years of extreme climate, with cold being the principal vector. D A T E BC

A R C HA E OL OGICAL EVENT

c. 5500*

Mesolithic microblade to large blade transition.

c. 4000* Well-defined

start of Neolithic.

c. 3200*

Neolithic settlers arrive in Boyne Valley.

c. 2300*

End of Neolithic, start of the Bronze Age.

c. 1700–c.1200*

Middle Bronze Age.

c. 1200–c.1000*

‘Bishoplands phase’ of Late Bronze Age.

c. 1000–c. 900*

‘Roscommon phase’ of Late Bronze Age.

c. 900–c. 600

‘Dowris phase’ of Late Bronze Age.

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c. 7th–3rd centuries*

One of most enigmatic periods in Irish prehistory.

Table 2.5: Change points in Irish prehistory following Cooney and Grogan (1994). Dates marked with * coincide with those identified as significant from the tree-ring record, as listed in Table 2.4.

Such conditions could have caused the loss of consecutive harvests and could have caused extreme discomfort for agriculture-based populations. Once such possibilities are realised, extreme cases have to be considered, i.e. there could have been circumstances that collapsed agriculture altogether, requiring its re-introduction to the island. There is currently no particular evidence to suggest that this happened in the case of Ireland, but the possibility needs to be borne in mind. There are therefore several ways of deducing aspects of change in the Irish past and it is interesting to draw together a provisional list of dates from the various strands of tree-ring evidence (originally published in Baillie 2001), as shown in Table 2.4. If we turn to Cooney and Grogan’s (1994) book Irish Prehistory, A Social Perspective it is possible to list the following dates cited by them as change points in Irish prehistory (Table 2.5); the dates would be regarded as generally acceptable by most prehistorians. The similarity between the dates in Table 2.5 (those marked with *) and some of the dates provided in Table 2.4, especially given the difficulties experienced by archaeologists when attempting to 105

date cultural change, implies that environmental factors that affected the trees or their survival, had some direct bearing on the happenings and changes, identified in the Irish archaeological record.

Longer Distance Connections Shortly after the ‘narrowest ring events’ were discovered in the Irish oak record it became clear that the environmental effects were not always restricted to Irish trees. From early on in the tree-ring project, it was possible to compare tree-ring patterns from different areas within Ireland with those from Scotland, England and Germany. In fact it was these long-distance comparisons that allowed the chronologies to be replicated. So, for example, we can compare long records from Ireland and England back to 5000 BC. Most of the time the growth patterns are very similar, but from time to time notable opposite departures are observed. These ‘differences’ imply changed growth conditions on opposite sides of the Irish Sea and these episodes may have interesting implications for how the environment affected populations in the different regions. Such thinking can be extended by making comparisons between the long Irish, English and German oak records, all of which exist for the whole of the last seven millennia.

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Figure 2.4: Comparison of the northern hemisphere pine density record, NHD1 (from Briffa et al. 1998), with a generalised European oak chronology. There is notable similarity in response at AD 1601, contrasted with notable differences at AD 1635 and AD 1641. It is also now possible for some periods (especially in the last few millennia) to make comparisons globally, i.e. to view Irish and European oak growth in the wider context of tree-growth throughout the temperate world. Such a statement would have been impossible before 1990. To take a recent example, Briffa et al. (1998) have analysed ring widths and ring densities in pine chronologies from around the Northern Hemisphere. They note that maximum late-wood density is a good reflection of summer temperature, so they can produce a summer temperature record for a large swathe of the Northern Hemisphere for high latitude/high altitude sites. They note that the coolest years in the last 600 years consistently

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coincide with known volcanic events. This makes sense in that explosive volcanoes inject dust and acid into the stratosphere causing cooling at the earth’s surface. However, the trees they are using are relatively rarefied, growing in temperature sensitive areas. We, on the other hand, are dealing with temperate oaks. Because all the tree-ring records are precisely dated, European dendrochronologists can compare their growth records with this published density record (called NHD1). When we do this we find that there are interesting differences in response. Figure 2.4 shows the two records across the early seventeenth century AD. There are some cooling events, such as AD 1601, that show in both records. However, there are other episodes where the oaks show no significant effects, such as at AD 1641 when the pines show a notable cooling, and some, for example around AD 1635, where the oaks are badly affected at times when the pines show no density reduction. Examination of such records allows us to get a feel for local and global effects involving some aspect of temperature. There is no doubt that as more and more regional chronologies become available a whole range of interesting comparisons will become possible between both temperature and moisture-sensitive records and tree-ring data.

Some Point Events–Splitting Up Archaeological Time The principal effect of producing a dendrochronological time-scale has been to introduce real dates into the previously somewhat vague archaeological time-scale that existed in Ireland. In our view, the main effect of identifying events of various kinds has been to split up ‘time’ into more manageable units. To give an example, if there are independently observed events at around 4000 BC, 3200 BC 108

and 2350 BC in tree-ring records, then, from a discussion point of view, the Irish Neolithic is forced to conform–to fit itself around–those events. Perhaps not surprisingly it does just that, with the generally accepted arrival of the Neolithic being around 4000 cal. BC, the Early Neolithic continuing until around 3200 cal. BC and the Bronze Age beginning (and the Neolithic ending) somewhere in the vicinity of 2500–2300 cal. BC. Moreover, if people wish to explore the possibility of pre-elm decline cereal pollen (e.g. Edwards and Hirons 1984) then this can be assigned to the period before 4000 cal. BC, i.e. before the environmental episode which seems to have taken place centred around 3900 BC on the tree-ring scale. Indeed, we can look at this episode in just a little more detail. Ballynagilly, the Neolithic house site in Co. Tyrone, was located on a low hill beside a peat bog. The palynology of this bog was studied by Jon Pilcher as part of his PhD thesis (Pilcher 1970). A layer of charcoal in the bog, consistent with the Neolithic occupation of the house site dates to around 3900 cal. BC. Pilcher noted that at the time when the Neolithic house was occupied, the bog was a lake and the charcoal represented deposition in lake sediment (lake mud texture as opposed to peat texture). This was interesting because in 1989 a pit was dug into the bog at Ballynagilly in order to obtain bulk samples for research into pre-elm decline cereal occurrence. When the Neolithic charcoal layer was reached it was discovered that a full pine trunk was lying horizontally just below the charcoal. This tree must have grown in relatively dry conditions (certainly not in a lake). So, with 185 growth rings and a radiocarbon determination (on rings 51–70) of 5259 ± 23 BP, i.e. c. 4200–4000 cal. BC, we can surmise that there had been a long, relatively dry, period in the centuries before 4000 cal. BC. This fits well with a separate observation published by Baillie and Brown 109

(1996). Here, date ranges of radiocarbon-dated pines from locations around lake margins (trees that had come to light when lake levels were lowered, or whose location indicated that water levels was relatively low when the trees were alive) were plotted against the overall replication of bog oaks. It was observed that there were several occurrences of lake-edge pines between 5000 and 4000 cal. BC, implying generally drier conditions during that period. Figure 2.5 shows the life spans of dendrochronologically-dated oaks that conform to this same model, i.e. oaks from lake margins. Here, we also see the occurrence of many such oaks between 5000–4000 BC. Putting all this information together it seems that around 4000 cal. BC (in a range suggested elsewhere to be bracketed by 4000–3800 cal. BC) there is a change from relatively dry to relatively wet conditions. So, although the story requires further refinement there is little doubt that a picture is emerging that allows us to see the archaeological Neolithic in a broader environmental context.

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Figure 2.5: The frequency of Irish bog oaks (from Fig. 2.3) with the dates of lake-edge oaks plotted for comparison. It is evident that conditions must have been much drier between 5000–4000 BC. Most of the evidence involving lake-edge oaks and pines relates to trees from small lakes. However, in Ireland, Lough Neagh is of special interest because of two factors; firstly its enormous size, and secondly its single exit to the sea via the Lower Bann. This means that Lough Neagh levels may not be controlled purely by the amount of precipitation. The single exit means that the level could be partly controlled by blockages of various kinds. On at least two occasions, most notably at 2350 BC (Baillie 1995a) and at AD 540 (Baillie 1995b), there are good grounds for suggesting that there were significant changes in the level of the Lough. The former event is suggested by damage/ anomalies in trees from both the north and south of the Lough, the latter by the discovery of an unfinished dug-out in the Lough at around AD 540, coupled with the observation of dramatic growth effects in several bog oaks from the lake edge. In the case of the 2350 BC ‘event’ (starts 2354, lasts until 2345), the strangest twist is the coincidence of the date with a reference in the Anno Mundi section of the Irish Annals that refers to lakes ‘breaking out’ with a date of ‘2341’ BC and mentioning the ‘Plain of Lough Neagh’ (Baillie 2001). We can obviously look at other events, in some cases very short-term events. For example, the European oak chronologies show an interesting growth downturn at AD 235–7. What serves to make this interesting is that the downturn may have been due to the explosive eruption of the Taupo volcano in New Zealand. For some time, there has 111

been a debate as to whether Taupo erupted around AD 186 or around AD 235. Although the answer is not known with any certainty, workers who have studied the exceptionally explosive nature of the eruption have gone so far as to suggest a global shock wave (Lowe and de Lange 2000). This implies it is possible that people in Ireland at the time may actually have heard, or felt the effects of, a volcano on the opposite side of the world. Ironically, the archaeological record in Ireland is sufficiently thin during the first few centuries AD that there is no way of knowing whether the events around AD 235 had any effect on Irish populations.

Conclusions Dendrochronological dates and environmental information from the tree-ring chronologies allow the piecing together of new pictures of the Irish past. At a detailed level, the examples given demonstrate the potential of having access to such information. They also serve to reinforce the major step down from absolute dating precision given by complete tree-ring samples to the much less precise ranges deduced from incomplete samples. In this context it is worth repeating the comments relating to the tenth century BC construction episode as an example. Because it is possible to have independent information on past environmental conditions at annual resolution, we want to test the hypothesis that building in wet areas was conditioned by environmental considerations. This demands that the dates of construction be ascertained to equivalent precision i.e. that complete sapwood is sought specifically. However, this exposes a dilemma. Excavators requiring dendrochronological dates are normally asking fairly coarse questions, such as ‘is our site/structure sixteenth or tenth century BC’? Once the excavator has an answer to, say, decadal precision, that is adequate for his or 112

her purpose. The dendrochronologists are, however, asking more refined quasi-annual questions. In an ideal world, once a site/ structure is dated, more samples should be obtained to allow the maximum dating refinement. Unfortunately, this is not in the archaeologist’s brief; neither is it possible for the dendrochronologist to return to excavation sites and arbitrarily acquire more samples with complete sapwood. The only logical answer is that budgets include provision for the acquisition of additional samples with sapwood. Only such an approach will help us out of the impasse where 28 Late Bronze Age sites can be dendrochronologically dated but, of these, only five can be realistically interpreted.

References Baillie, M. G. L. 1982. Tree-Ring Dating and Archaeology. London: Croom-Helm. Baillie, M. G. L. 1989. Hekla 3–just how big was it? Endeavour 13, 78–81. Baillie, M. G. L. 1990. Irish tree-rings and an event in 1628 BC, pp. 160–6 in Hardy, D. A. (ed.), Thera and the Aegean World (Vol. 3). London: The Thera Foundation. Baillie, M. G. L. 1992. Dendrochronology and past environmental change. Proceedings of the British Academy 77, 5–23. Baillie, M. G. L. 1993. Archaeological wood in Ulster. Archaeomaterials 7, 139–50. Baillie, M. G. L. 1995a. Dendrochronology and the chronology of the Irish Bronze Age, pp. 30–7 in Waddell, J. and Shee Twohig, E. (eds.), Ireland in the Bronze Age. Dublin: The Stationery Office.

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Baillie, M. G. L. 1995b. A Slice Through Time: Dendrochronology and Precision Dating. London: Routledge. Baillie, M. G. L. 1999. A view from outside: recognising the big picture. Quaternary Proceedings 7, 1–11. Baillie, M. G. L. 2001. Some things we will never know: exploring the limits of cause and effect in environmental research, pp. 43–54 in Raftery, B. and Hickey, J. (eds.), Recent Developments in Wetland Research (Monograph Series No. 2). Dublin: Department of Archaeology, University College Dublin. Baillie, M. G. L. and Brown, D. M. 1991. A dendro-date from Haughey’s Fort? Emania 8, 39–40. Baillie, M. G. L. and Brown, D. M. 1996. Dendrochronology of Irish bog trackways, pp. 395–402 in Raftery, B., Trackway Excavations in the Mountdillon Bogs, Co. Longford (Irish Archaeological Wetland Unit, Transactions Vol. 3). Dublin: Department of Archaeology, University College Dublin. Baillie, M. G. L. and Brown, D. M. 1998. The dendro-date from Haughey’s Fort. Emania 17, 45–6. Baillie, M. G. L. and Brown, D. M. 2002. Oak dendrochronology: some recent archaeological developments from an Irish perspective. Antiquity 76, 497–505. Baillie, M. G. L. and Munro, M. A. R. 1988. Irish tree-rings, Santorini and volcanic dust veils. Nature 332, 344–6. Briffa, K. R., Jones, P. D., Schweingruber, F. H. and Osborn, T. J. 1998. Influence of volcanic eruptions on Northern

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Hemisphere summer temperature over the last 600 years. Nature 393, 450–5. Brown, D. M. 2002. Dendrochronological dated building from Ireland. Vernacular Architecture 33, 71–3. Cooney, G. and Grogan, E. 1994. Irish Prehistory: A Social Perspective. Bray: Wordwell. Crone, A. 2000. The History of a Scottish Lowland Crannog: Excavations at Buiston, Ayrshire 1989–90. Edinburgh: Scottish Trust for Archaeological Research. Edwards, K. J. and Hirons, K. R. 1984. Cereal pollen grains in pre-elm decline deposits: implications for the earliest agriculture in Britain and Ireland. Journal of Archaeological Science 11, 71–80. Hillam J., Morgan, R. and Tyers, I. 1987. Sapwood estimates and the dating of short ring sequences, pp. 165–85 in Ward, R. G. W. (ed.), Applications of Tree Ring Studies (BAR International Series 333). Oxford: British Archaeological Reports. Lowe, D. J., and de Lange, W. P. 2000. Volcano-meteorological tsunamis, the c. AD 200 Taupo eruption (New Zealand) and the possibility of a global tsunami. The Holocene 10, 401–7. McErlean, T. and Crothers, N. 2001. Tidal power in the seventh and eighth centuries AD. Archaeology Ireland 15 (2), 10–14. Pearson, G. W., Pilcher, J. R., Baillie, M. G. L., Corbett, D. M. and Qua, F. 1986. High-precision 14-C measurement of

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Irish oaks to show the natural 14-C variations from AD 1840 to 5210 BC. Radiocarbon 28, 911–34. Pilcher, J. R. 1970. Palaeoecology and the Radiocarbon Dating of Sites in Co. Tyrone, Northern Ireland. Unpublished Ph.D. Thesis, Queen’s University Belfast. Pilcher, J. R., Baillie, M. G. L., Schmidt, B. and Becker, B. 1984. A 7272-year tree-ring chronology for Western Europe. Nature 312, 150–2. Raftery, B. 1990. Trackways Through Time: Archaeological Investigations on Irish Bog Roads 1985–89. Dublin: Headline.

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3 The Use of Tephra in Linking European Sequences of Terrestrial, Lacustrine, Marine and Ice Palaeoenvironmental Records Jon R. Pilcher

Abstract Tephra provides a valuable additional chronological and stratigraphical tool for the palaeoecologist and environmental archaeologist. It is proving particularly useful in north-west Europe where well-dated Icelandic tephras provide good chronological control. Improved concentration and detection methods now permit the use of these valuable chronological markers in a wide range of Quaternary deposits. Chronologies established using clean ombrogenous peats can now be applied to lacustrine and marine sediments of low organic content. Study of tephra layers in well-dated ice cores will lead to much improved dating for tephras from prehistoric times.

Introduction Tephra is the air-fall component of ejecta from a volcano. Strictly speaking, it includes glassy material and crystalline

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material from the magma and also any broken volcanic cone rock that is carried into the atmosphere. The glassy component is liquid magma that cools rapidly as it is shot into the atmosphere and forms a glass without crystallising. The quantities produced can be huge–geologists describe eruptions in terms of the number of cubic kilometres of ash produced–and it is shot many kilometres into the atmosphere. Thus, it is not really surprising that it can travel long distances from its source. Because eruptions are generally short-lived, tephra layers provide very precise time markers in sediments and deposits. They have the potential to provide an additional time control to archaeologists to supplement radiocarbon dating. Tephras (in this case visible layers) have been used extensively in the study of the early settlement of Iceland and the Faroe islands (Dugmore and Newton 1998; Wastegaard et al. 2001). Using the methods described here to identify much smaller amounts of tephra, the technique can now be extended to Ireland and Britain and other parts of north-west Europe.

Geographical Distribution and Temporal Range Tephras may be found in many areas of the world, and in fact there is probably no part of the globe where tephras are unlikely, albeit in low concentrations. It has been claimed that tephra from an eruption in AD 1259 has been found in both the Arctic and the Antarctic ice sheets (Ram and Gayley 1991; Palais et al. 1992). Their use in stratigraphic studies and as a dating tool is well developed in north-west Europe using Icelandic tephra (Dugmore et al. 1995; Pilcher et al. 1996; Hall and Pilcher 2002; van den Bogaard and Schmincke 2002), in North Island New Zealand (Froggatt and

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Lowe 1990) and in northern USA (Beget and Keskinen 1991; Beget et al. 1991). Similar work is in progress in many other areas such as Mexico, the Antarctic Peninsula (Bjork et al. 1991), the Falkland Islands (Hall et al. 2001) and Kamchatka (Russian Federation) (Braitseva et al. 1993) etc. Most of these studies concentrate on the Late Quaternary and Holocene.

Practicalities Most tephra studies so far have been on continuous sequences such as peat bogs and lake sediments. Samples for archaeological dating would ideally use similar sequences–ditch fill deposits, for example. Where single samples from sealed archaeological contexts are investigated the greatest care must be taken to ensure stratigraphic integrity. A contaminated tephra sample is just as useless as a contaminated radiocarbon sample! It is difficult to give guidelines for sample size that are generally applicable. For peat and lake sediments a sample of about 5 cm2 surface area would be used. Because extraction from mineral soils is more complex, twice this surface area might be a good target when sampling these types of soils and sediments.

How do we Detect Tephra in a Sediment Core or Sample? Tephra particles are typically less than 100 microns (commonly 20–60µ) in size and are glass. The ideal medium for detection is in a highly organic matrix such as peat. All we need to do is burn the organic material, dissolve the peat ash in dilute hydrochloric acid (10% HCl) and wash the tephra and other minerals clean. The clean material can then be mounted in resin and examined under a microscope at about x100 magnification. This process is described by Pilcher and Hall (1992). Where the matrix has more than about 1% 119

mineral content the separation of the tephra is more difficult. Sieving between mesh sizes of 26 and 75µ will retain most of the tephra and will remove all the fine clay and silt particles. If this is not adequate, then we resort to separation using a heavy liquid (Lowe and Turney 1997). Sodium polytungstate dissolved in water provides densities up to about 3.2. As the glass of the tephra is relatively light it can be floated off most other minerals using a density of 2.5. Density separations are quite time consuming and the heavy liquid is very expensive and must be recovered and re-used. Preparation of samples from lacustrine sediments may need additional treatment to remove diatoms. These have a similar density to the tephra and follow the tephra in the heavy liquid separation. Prolonged treatment (2–4 hours) with warm potassium hydroxide at a concentration less than 10% will dissolve most diatoms and has been demonstrated not to affect the tephra chemistry.

Preparation for Geochemistry The simple preparation by burning is not suitable when chemical analysis is required as the burning changes the nature of the glass chemistry. In this case the organic matter is dissolved in a chemical oxidising mixture of concentrated sulphuric acid and concentrated nitric acid as described in Hall and Pilcher (2002). The tephra recovered from the acid treatment is washed on a 26µ sieve mesh. At this point microscopic assessment will determine whether either or both of the diatom treatment or the heavy liquid separation, described above, will be needed. Finally, the clean tephra is dried onto a ground glass slide. The tephra is covered in a layer of epoxy resin (Araldite). When this has set the preparation is ground using 12µ alumina on a glass plate until

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the tephra is positioned just at the surface. The slide is then polished using diamond or alumina polishing powders until the surface is smooth, and flat surfaces of the tephra exposed. The difference between a perfect slide and one on which all the tephra has been ground or polished away is only a few microns!

Recognition of Tephra There is a wide range of tephra morphologies and colours. While these can be some guide to origins they are not capable of providing a definitive identification. Examples (a) to (d) in Figure 3.1 show some of the different morphologies and colours seen in Icelandic tephras. Van den Bogaard and Schmincke (2002) highlight the diagnostic value of crystalline inclusions in some tephra particles. One of the greatest problems facing those starting tephra studies is that of distinguishing tephra from biogenic silica. Biogenic silica comes in many forms and some will survive the alkaline treatment mentioned above. Morphologically distinct forms such as diatoms and many plant phytoliths are not a problem, but other types that have formed inside higher plant cells can often mimic the shape of large tephra bubbles. Example (e) in Figure 3.1 shows various biogenic silica bodies that have been found in tephra preparations. With experience, the biogenic silica can be distinguished by its different refractive index and often by a very fine sculpturing of the surface that can be seen at high magnification of the light microscope. The effect of the refractive index depends on the refractive index of the mounting medium. With the histomount medium used by the author, the biogenic silica tends to have a bolder outline than the tephra.

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The results of microscope identification can be expressed graphically alongside other stratigraphic information. Figure 3.2 shows a stratigraphic sequence from Garry Bog in Co. Antrim, Northern Ireland. The peat monolith was sampled at 1 cm intervals and prepared by the burning technique. Selected samples were prepared by wet chemistry and the tephras identified by microprobe analysis (see below).

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Figure 3.1: Different morphologies and colours seen in some Icelandic historic tephras. a) Hekla AD 1510, b) Oraefajokull AD 1362, c) Hekla AD 1104 (‘Hekla 1’), d) Unknown origin c. AD 1250 and e) various biogenic silica bodies that have been found in tephra preparations.

Chemical Fingerprinting of Tephras Volcanic systems differ in their chemistry, individual volcanoes may also differ and in some cases, such as in Iceland, many individual eruptions are distinct. This distinction is much clearer in some places than others. For example, in South America many eruptions share the same chemistry. In the distal tephra studies described here it is not possible to collect enough tephra for X-ray fluorescence (XRF) analysis, so we use electron microprobe analysis of single shards of tephra. Because the differences between eruptions are quite subtle it is normal to use the more sensitive wavelength dispersive microprobe analysis rather than the simpler and more commonly available energy dispersive analysis. The wavelength dispersive analysis requires a flat surface, hence the need to mount the tephra in resin and grind and polish the preparation. This has the added advantage that it exposes a fresh surface of the tephra. It is clear from the pitted surface sometimes seen in prehistoric tephras that some degradation of the surface occurs with age (Dugmore et al. 1992).

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Figure 3.2: Stratigraphic tephra sequence from Garry Bog in Co. Antrim, Northern Ireland. Both sodium and potassium are important diagnostic elements in volcanic glass. However, it is a feature of glasses that the sodium and to a lesser extent the potassium in the glass is driven out by the heat from the electron beam during microprobe analysis (Hunt and Hill 1993). Sodium must be analysed first to reduce this problem and it is usual to de-focus the beam to about 8µ diameter to reduce the heating. The operating conditions of the microprobe may also affect the extent of sodium loss. We operate the Belfast Jeol 733 Superprobe at 15 kv and 10 na beam current. It is usual to analyse somewhere between ten and 20 individual tephra fragments. For some glasses as few as five analyses may be diagnostic, but where a particular volcano has produced tephra of varying composition during the course of an

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eruption many analyses may be needed to obtain a representative population (Dugmore et al. 1992). One of the main reasons for the rapidly increasing success of tephra studies in north-west Europe has been the ability to locate and chemically identify very low concentrations of tephra. Hall and Pilcher (2002) describe the identification of concentrations as low as 1–2 tephra fragments per cm3 of peat. This is achieved by using a light microscope with x–y mechanical stage to record the positions of individual tephra particles on a slide and then converting these co-ordinates to the x and y stage co-ordinates of the microprobe. This allows the microprobe to be driven directly to the tephra particle. Many modern microprobes have no optical imaging capability. This eliminates the very valuable use of polarised light to distinguish crystalline minerals from the glassy tephra. Even where there is an optical system these are never of the quality of a good research light microscope and the separation of tephra from biogenic silica using such optics stretches the capabilities of the most experienced tephra analyst!

Type Material and Matching Type material comes from profiles examined in Iceland. Many have been analysed, many more remain to be done. Tephra stratigraphies close to the source volcanoes are extremely complex, with much re-working and wind- and water-generated movement of tephras. Much of the work on type material has been carried out on clearly stratified sequences in the peat bogs of northern Iceland (Larsen and Thorarinsson 1997; Larsen et al. 1999). Work in a new area benefits from the construction of a detailed tephra stratigraphy using the best possible 125

ombrogenous peat sequence before moving on to work on more difficult series from lacustrine or near-shore marine deposits. Analyses based on microprobe analysis as described above are stored in an international tephra data bank (TEPHRABASE) and are available to all researchers at the following web address: http://www.geo.ed.ac.uk/tephra/ tbasehom.html

Why is Tephra Useful? A typical eruption lasts for days or perhaps even months, but a very short time in relation to typical archaeological timescales and to bog and lake stratigraphy. Thus, an ash layer forms a highly defined time marker. Apart from tephra, such isochrons are rare in lake sediments and almost unknown in peat bogs. In an archaeological context, one might hope to find a known-age tephra below or above a cultural context that would provide a bracketing date. Such dates can be very useful when combined, using Bayesian statistics, with a series of radiocarbon measurements. There is considerable potential for using tephra in wetland archaeology where tephras could potentially provide a link between cultural layers in the archaeological site and palaeoenvironmental contexts nearby.

Tephra for Correlation Between Cores, Between Sample Sites and Between Regions One of the perennial problems of working in bog and lake deposits is correlation from one core to another. Magnetic susceptibility is quick and sometimes works well but with highly organic sediments will often not provide a definitive link. Tephra is ideal for this as the markers are so sharp. It is a mistake to believe that it is a quick technique, however. It is normally assumed that parallel cores taken a few metres apart 126

on the same day are going to be comparable. If one core is used for pollen analysis and the other to provide material for AMS dating or for chemical analysis then tephra may provide an insight into critical offsets between the two cores.

Tephra as a Taphonomic Guide This I believe to be one of the most valuable things that tephra can tell us and so far has been very little used. As the tephra fall is assumed to be at least within a single year we can make a good assessment of post-depositional processes by looking at the vertical spread of the tephra in a sediment core. As the particle size of the typical tephra layer is of the same order as that of pollen, for example, it can suggest the extent to which pollen may have been moved vertically in the sediment profile. If the tephra is spread over 5 cm, there would be little point in undertaking a pollen study at 1 cm resolution! The upper graph in Figure 3.3 shows fine resolution sampling over a tephra layer in Sphagnum peat. In this medium there appears to be very little tephra movement and 80% of the tephra is restricted to 8 mm. In contrast, the lower graph in Figure 3.3 shows sampling in an upland blanket peat where there has clearly been considerable tephra movement. Such material would not be appropriate for a high resolution pollen study, and the findings also suggest that other studies such as radiocarbon dating need to be carried out with caution.

Tephra as a Chronology This depends, of course, on knowing when eruptions took place and then of tying a tephra fall to a particular eruption. Iceland has been settled since about 850 AD and the inhabitants have kept detailed records of eruptions since that time. From about 1100 AD, we have a well recorded 127

chronology of calendrical accuracy (N. Ogilvie 2005, pers. comm.). Before settlement in Iceland we are dependent on dating tephra layers by independent means. Radiocarbon dating is clearly a possibility but this raises the question of would it not be just as good to date the sediment core directly rather than date tephra somewhere else then relate it to the sediment core. There are actually several good reasons for doing this and these centre on radiocarbon’s ability to provide accurate dates. We can pick an ideal material for radiocarbon dating, such as fast-grown Sphagnum peat, and then apply the date to material such as low-organic lake sediment or marine or brackish water sediment that is unsuitable for precision radiocarbon dating. Even using high precision radiocarbon dating will not provide adequate precision in some time periods because of the nature of natural radiocarbon variations (Pilcher 1993; see Barratt and Reimer, this volume). In some time periods, a radiocarbon measurement may relate to a range of real ages–for instance, samples of several different real ages may all have the same radiocarbon date. One way round this is to use a technique called ‘wiggle matching’. A series of samples (typically five or more samples) covering the event in question are measured using the highest available radiocarbon precision. These measurements can then be compared with the ‘wiggles’ in the radiocarbon calibration curve. This technique was tested on the known-age eruption of Hekla in AD 1104. The best estimate of the date of the eruption based on the wiggle match was 1088 ± 20 BP. The application to an eruption of unknown date is illustrated in Figure 3.4, which shows the wiggle match dating of the Icelandic Hekla 4 eruption (Pilcher et al. 1996). We used a Sphagnum-rich ombrogenous peat in which

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the tephra was sharply defined. Five radiocarbon samples were measured with a precision of ± 18 years and the sequence matched to the calibration curve. The technique has been used on several other eruptions such as Hekla 3 (van den Bogaard and Schmincke 2002) and the mid-Holocene ‘Lairg’ tephras, dated to 4774–4677 cal. BC and 4997–4902 cal. BC (Pilcher et al. 1996). It is thus clearly easier to obtain accurate dates on individual tephras, than it is on individual horizons of interest at different sites of varying sediment and stratigraphy.

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Figure 3.3: Upper graph–Fine resolution sampling over a tephra layer in a Sphagnum peat. In this medium there appears to be very little tephra movement and 80% of the tephra is restricted to 8 mm. Lower graph–Sampling in an upland blanket peat where there has clearly been considerable tephra movement.

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Figure 3.4: Wiggle match dating of the Icelandic Hekla 4 eruption (Pilcher et al. 1996).

Tephra from Ice Cores The detection of tephra from ice cores opens up the possibility of using the superior chronology of the most recent ice cores to date prehistoric tephras and thus assist in the correlation of the huge climate archive in the ice with those in terrestrial and marine sediments. In the most recent Greenland ice core–North Grip (NGRIP)–an automated chemical analysis system was implemented in the drill-site laboratory. The melted ice for analysis was filtered through micropore filters and these filters were kept for future analysis of the particulate content. We have prepared a selection of these filters for microprobe analysis by embedding slices of filter in Araldite resin rather than trying to wash particles off the filter. Successful light microscope detection of tephra was

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achieved and the same slides were then ground and polished for microprobe analysis. Samples of the archived older ice cores such as GRIP are being melted and the water centrifuged to concentrate particulate matter for tephra analysis.

An Example of the Use of Tephra in a Palaeoenvironmental Investigation Recently, a team from the University of Massachusetts at Amherst and Queen’s University of Belfast went to the Lofoten Islands off the north-west coast of Norway, just inside the Arctic Circle, to look for sediment that might give information on the past position of the Polar Front during the Holocene. Because we were working in a range of terrestrial, brackish and marine sediments we hoped to use tephra as an additional dating method. As no tephra work had been done in this area before, we selected several peat profiles to develop a local tephra stratigraphy before trying to apply this to more difficult lake sediments. One profile has been fully analysed. The stratigraphy contains identified Icelandic tephras of AD 1362, AD 1158 and AD 1104 eruptions and also the big eruption of Hekla in 2310 BC. A more recent layer may be the AD 1510 eruption of Hekla and the profile extends back to the late glacial where the well-known Vedda tephra was detected. In all some 24 district tephra layers were isolated (Pilcher et al. 2005). Once we know where the key dating layers are we can start to look for these in the lake cores. It is too time-consuming to process each lake sediment and brackish water core so we use AMS dating of terrestrial macrofossils to roughly define time

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periods of likely interest. Once tephras have been found we can use them to assess the bioturbation in the cores and can correlate from core to core and lake basin to lake basin. Eventually, we will be able to correlate our findings with other work on a transect along the Atlantic seaboard of Europe, focusing on key dates such as the 2310 BC eruption.

Problems — It sounds easy! Identification of the tephra requires a lot of very careful microscopy. Experience with a technique such as pollen or diatom analysis is a distinct asset. — Microprobe analysis requires access to a microprobe capable of critical wavelength dispersive analysis. — Not all areas receive tephra. Experience with the fall-out of the Chernobyl disaster shows how patchy aerosol fall out can be. — Not all tephras are chemically distinct. For example the AD 1947 and AD 1510 tephras from Hekla are very similar, as are those of Hekla 4 (2310 BC) and Hekla 5 (5990 BC). Normally, other stratigraphic information allows these to be separated.

References Beget, J. and Keskinen, M. 1991. The Stampede tephra: a middle Pleistocene marker bed in glacial and aeolian deposits of central Alaska. Canadian Journal of Earth Sciences 28, 991–1002. Beget, J., Edwards, M., Hopkins, D., Keskinen, M. and Kukla, G. 1991. Old Crow tephra found at the Palisades of the Yukon, Alaska. Quaternary Research 35, 291–7.

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Bjork, S., Sandgren, P. and Zale, R. 1991. Late Holocene tephrochronology of the northern Antarctic peninsula. Quaternary Research 36, 322–8. Bogaard, C. van den and Schmincke, H-U. 2002. Linking the North Atlantic to central Europe: a high resolution Holocene tephrochronological record from Northern Germany. Journal of Quaternary Science 17, 3–20. Braitseva, O. A., Sulerzhitsky, L. D., Litasova, S. N., Melekestsev, I. V. and Ponomareva, V. V. 1993. Radiocarbon dating and tephrochronology in Kamchatka. Radiocarbon 35, 363–476. Dugmore, A. J. and Newton, A. J. 1998. Holocene tephra layers in the Faroe Islands. Frodskaparrit 46, 191–205. Dugmore, A. J., Larsen, G. and Newton, A. J. 1995. Seven isochrones in Scotland. The Holocene 5, 257–66. Dugmore, A. J., Newton, A. J. and Sugden, D. E. 1992. Geochemical stability of fine-grained silicic Holocene tephra in Iceland and Scotland. Journal of Quaternary Science 7, 173–83. Froggatt, P. C. and Lowe, D. J. 1990. A review of late Quaternary silicic and some other tephra formations from New Zealand: their stratigraphy, nomenclature, distribution, volume, and age. New Zealand Journal of Geology and Geophysics 33, 89–109. Hall, V. A. and Pilcher, J. R. 2002. Late Quaternary Icelandic tephras in Ireland and Great Britain: detection, characterization and usefulness. The Holocene 12, 223–30.

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Hall, V. A., Holmes, J. and Wilson, P. 2001. Holocene tephrochronological studies in the Falkland Islands, pp. 39–44 in Juvigne, E. and Raynal, J. P. (eds.), Tephras; Chronology and Archaeology (Les dossiers de l’Archeo-logis No 1). Goudet: Conseil-General de Haute Loire. Hunt, J. B. and Hill, P. G. 1993. Tephra chemistry: a discussion of some persistent analytical problems. The Holocene 3, 271–8. Larsen, G. and Thorarinsson, S. 1977. H4 and other acid tephra layers. Jokull 27, 29–47. Larsen, G., Dugmore, A. J. and Newton, A. J. 1999. Geochemistry of historical age silicic tephras in Iceland. The Holocene 9, 463–71. Lowe, J. J. and Turney, C. S. M. 1997. Vedde ash discovered in a small lake basin on the Scottish mainland. Journal of the Geological Society 154, 605–12. Palais, J. M., Germani, M. S. and Zielinski, G. A. 1992. Inter-hemispheric transport of volcanic ash from a 1259 A.D. volcanic eruption to the Greenland and Antarctic ice sheets. Geophysical Research Letters 19, 801–4. Pilcher, J. R. 1993. Radiocarbon dating and the palynologist: a realistic approach to precision and accuracy, pp. 23–32 in Chambers, F. M. (ed.), Climate Change and Human Impact on the Landscape. London: Chapman and Hall. Pilcher, J. R and Hall, V. A. 1992. Towards a tephrochronology for the Holocene of the north of Ireland. The Holocene 2, 255–9.

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Pilcher, J. R., Hall, V. A. and McCormac, F. G. 1995. Dates of Icelandic volcanic eruptions from tephra layers in Irish peats. The Holocene 5, 103–10. Pilcher, J. R., Hall, V. A. and McCormac, F. G. 1996. An outline tephrochronology for the north of Ireland. Journal of Quaternary Science 11, 485–94. Pilcher, J. R., Bradley, R. S., Francus, P. and Anderson, L. 2005. A Holocene tephra record from the Lofoten Islands, Arctic Norway. Boreas 34, 1–21. Ram, M. and Gayley, R. I. 1991. Long-range transport of volcanic ash to the Greenland ice sheet. Nature 349, 401–4. Wastegaard, S., Bjorck, S., Grauert, M. and Hannon, G. E. 2001. The Mjauvotn tephra and other Holocene tephra horizons from Faroe Islands: a link between the Icelandic source region, the Nordic Seas and the European continent. The Holocene 11, 101–9.

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4 Human Osteoarchaeology in Ireland Eileen M. Murphy

Abstract Human osteoarchaeology has been growing from strength to strength in Ireland in recent years. The current paper begins with a brief introductory review of the history of the discipline within an Irish context. This is followed by an overview of some of the main methodologies employed in the general analysis of archaeological human skeletal remains. The final section of the text addresses the issue of why it is important to study archaeological human skeletons. A number of the main themes of relevance to human osteoarchaeological studies, including demography, health, trauma and diet, are explored and illustrated using Irish case studies (Fig. 4.1).

Introduction Human skeletal remains represent one of the most tangible forms of archaeological evidence since they are the actual physical remains of our ancestors–the very people who were responsible for the creation of all other archaeological evidence that we encounter in our work as archaeologists. Osteoarchaeological and palaeopathological analyses of human skeletal remains can provide us with great insights

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concerning the physique, health, diet and lifestyles of our ancestors. If a biocultural approach is employed –whereby the skeletal evidence is combined with information derived from a wide variety of sources, including artistic and documentary records, the environment and material culture–it is possible to gain an even more holistic understanding of past populations (see Bush and Zvelebil 1989; Roberts and Cox 2003). This type of multidisciplinary approach can be particularly rewarding since it enables us to gain clearer insights into a variety of key themes of archaeological research, such as the nature of social structure, burial practices, labour divisions, warfare, economy and migrations. A review of the development of human osteoarchaeological research within an Irish context has recently been published by Murphy (2002a) but the current discourse provides an opportunity to synthesise the contents of that paper. As was the case for many parts of the world, nineteenth and early twentieth century research on archaeological human skeletal remains within Ireland concentrated on craniometric analysis. The main objective of this research was to enable the study of variation and affinities of past populations, thereby enabling researchers to identify indigenous and intrusive groups (e.g. Frazer 1890–91; Haddon 1896–98; Borlase 1897; Macalister 1921; Martin 1935). A number of substantial assemblages of human remains were subject to craniometric and osteometric analyses throughout the early and middle twentieth century, including the Early Christian populations from Gallen Priory, Co. Offaly (Howells 1941), and Castleknock, Co. Dublin (McLoughlin 1950). Palaeopathological analysis, which is now one the main aspects of human skeletal research, was largely ignored in early anthropological studies. One of the exceptions to this situation was the publication of a note by

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Walmsley (1923) on a cranium recovered from Nendrum monastery, Co. Down, which he considered to have displayed a trepanation. This paper represents one of the earliest attempts to look beyond osteometric analyses.

Figure 4.1: Location map of sites mentioned in the text.

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Throughout the 1960s, 1970s and early 1980s there was a general dearth of specialists on the island with the expertise to analyse archaeological human remains and it was necessary to have such analyses undertaken in Britain by recognised individuals, such as Professor Don Brothwell in England (e.g. Brothwell 1985; 1987) and Dr. J. L. Wilkinson in Wales (e.g. Brannon et al. 1990 writing of an excavation undertaken in 1985). During the mid-1980s a number of Irish archaeologists began to seek specialist postgraduate training and undertake research degrees in osteoarchaeology and palaeopathology (Power 1984; O’Donovan 1985), a pattern which continued through the 1990s (e.g. Buckley 1991; Murphy 1994; Lynch 1998) and into the new millennium (e.g. Keating 2001). Indeed, human osteoarchaeology is now one of the growth areas within Irish archaeology and there are now approximately 25 qualified osteoarchaeologists working on the island (L. Buckley 2006, pers. comm.).

Methodology Excavation A number of detailed guidelines for the excavation of both inhumed and cremated archaeological human remains exist, including McKinley and Roberts (1993). In addition, valuable documents have been produced in recent years which focus on the ethical and legal issues surrounding the excavation of archaeological human skeletal remains (e.g. O’Sullivan et al. 2002; Mays 2005). When a human skeleton is encountered during an excavation it is best practice that an osteoarchaeologist is present on site so that the remains of the individual can be partially examined in situ and advice on recording and recovery can be imparted to the excavators (Buckley et al. 1999). In situations where a trained

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osteoarchaeologist is not involved in the excavation and recovery of human skeletal remains there is a danger that strands of evidence will be overlooked. Kidney or gall stones, for example, are easily missed and discarded. It is often the case that in situ foetal bones present within the abdominal area of a pregnant individual are recorded, but little attention is given to the orientation of the foetus or his/her position within the pelvis. Both of these are important details which have the potential to provide insights as to why the baby and its mother may have died. At a basic level an osteoarchaeologist will be able to record information (such as lengths of the long bones) from a poorly preserved skeleton while it is still in situ; once the remains have been lifted from the ground it may no longer be possible to record these measurements due to the fragmentation of the bones. As such, important information concerning a person’s estimated living stature can be lost. It can also be easier for an osteoarchaeologist to interpret taphonomic processes that may have affected human skeletal remains if they have been involved in the excavation process. Certain soil conditions can affect human remains in a particular manner and result in extensive erosion. Remains recovered from shallow graves, or those which may have been disturbed in antiquity can display signs of weathering and bleaching. Burials recovered from contexts associated with voids can display signs of rodent gnawing. This was the case for a number of disarticulated bones recovered from Post-Medieval contexts within St. John’s Church, Islandmagee, Co. Antrim. During excavation it was thought that one of the crania displayed a trepanation, but osteological analysis revealed the perforation to have been caused by rodent gnawing (Murphy 2002b, 141).

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The juxtaposition of certain grave goods in close proximity to human skeletal remains can also affect the bones. For instance, during excavations at Tonybaun, Co. Mayo, the use of copper shroud pins had left discrete areas of green discoloration and soft tissue preservation on the remains of many individuals (Fig. 4.2) (Murphy 2004a; Nolan 2006). Indeed, there is much potential for the application of the anthropologie de terrain method, developed in France, to be applied to Irish burials from all periods. This method involves the detailed recording of skeletons in situ, and has the potential to yield a variety of information that is often overlooked. On the basis of subtle disturbances to the position of the bones, for example, it might be possible to infer that organic grave goods had originally been positioned alongside the body. At a more basic level the position of the bones can enable one to determine if a body had been buried within a coffin or placed straight into the ground, even in the absence of wood remains (see Nilsson Stutz 2003).

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Figure 4.2: Copper shroud pin with associated hair preservation on a fragment of cranium recovered from Tonybaun, Co. Mayo (Photo: E. Murphy). When dealing with collections of disarticulated human remains recovered from megalithic tombs or cave deposits the involvement of an osteoarchaeologist during the excavation process is even more critical. It is clear that our Neolithic ancestors were deliberately processing their dead and selecting particular parts of certain members of society for interment within these tombs. Cut marks have been identified on a fragment of mandible retrieved from the possible Late Neolithic site at Millin Bay, Co. Down (Murphy 2003), and a detailed study has been undertaken on taphonomic aspects of Neolithic remains recovered from Poulnabrone portal tomb and Parknabinnia chambered tomb in Co. Clare (Beckett 143

2005). Such post-excavation analyses are of course crucial but, again, analysis of collections of disarticulated groups of bones when still in situ has the potential to yield subtle forms of evidence that can be lost by the time the remains reach the laboratory for analysis. The position of larger bones may be clearly recorded in plans and photographs, for example, but such details for smaller skeletal elements are often lacking.

Post-excavation A number of high quality texts exist which provide details of the methodologies generally used in Western Europe and North America for the analysis of archaeological human skeletal remains (Ferembach et al. 1980; Brothwell 1981; Bass 1987; Ubelaker 1989; Buikstra and Ubelaker 1994; Brickley and McKinley 2004). Initially, the osteoarchaeologist attempts to answer a number of basic questions to enable a biological profile to be established for the individual. In the first instance it is necessary to ascertain whether the individual is an adult or a subadult. If the individual is an adult it is possible to determine whether they are male or female. On the basis of current morphological methods it is generally accepted that, prior to puberty, it is not possible to determine accurately the sex of subadult skeletons (Mays and Cox 2000, 126). In general, when a complete adult skeleton is present the sex can be established with 95–100% accuracy. If, however, only sections of the skeleton are present, then the accuracy of sex determination diminishes. Morphological analysis of the pelvis alone provides 90–95% accuracy; the skull provides 80–90% accuracy, while metrical analysis of long bones enables sex to be established with 80–90% accuracy (Krogman and Isçan 1986, 189; Ubelaker

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1989, 53–5). The morphology of the pelvis is different between males and females since the female pelvis is specially adapted to enable successful pregnancy and childbirth. Differences between the male and female skull arise because puberty generally occurs, on average, two years earlier in females relative to males. As a result, males have an additional two years of somatic growth, associated with an increase in muscle mass, which causes changes at the sites of muscle attachments and also as a response to muscle-related forces (Mays and Cox 2000, 118–9). A plethora of methods have been devised to enable age determination of both adults and subadults. The determination of the age at which an individual died involves the observation of morphological features in the skeletal remains and the comparison of the information with age-related changes recorded for modern-day populations of known age. This is followed by the estimation of any possible variability which may exist between the unknown and the recent population on which the comparative data is based (Ubelaker 1989, 63). There are two main periods in the life of a human–development, which occurs approximately between birth and 25 years of age, and degeneration, which occurs roughly from the age of 25 years onwards. It is easier to determine the age-at-death of children and adolescents than fully developed adults, since the growth and maturation of a subadult skeleton follows a reasonably predictable sequence (Chamberlain 1994, 13). Once the skeleton has completed its growth the age-related changes associated with degeneration do not progress at a predictable rate, making it more difficult to determine the age at which an adult died (Saunders 1992, 8).

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The age-at-death of subadults is generally determined from the analysis of epiphyseal fusion (Ferembach et al. 1980, 530–31; Brothwell 1981, 66), the diaphyseal length of the long bones (Ubelaker 1989, 70–1), dental eruption (Ubelaker 1989, 64) and dental calcification (Moorrees et al. 1963; Smith 1991, 161). It has been demonstrated for living subadult populations of known chronological age that dental age displays less variation than skeletal age (Scheuer and Black 2000a, 13). As such, greater emphasis is generally placed on subadult age determinations derived from dental remains. An invaluable corpus of information on subadult age determination methods can be found in Scheuer and Black (2000b). The main age determination methods used for skeletally mature individuals are dental attrition (Brothwell 1981, 72); cranial suture fusion (Meindl and Lovejoy 1985) and morphological changes of the auricular surface (Lovejoy et al. 1985), sternal ends of the ribs (Isçan and Loth 1986a; 1986b) and the pubic symphysis (Brooks and Suchey 1990). None of these methods are without problems, however, and a discussion of these can be found in Cox (2000), while recommendations for determining adult age-at-death estimates are outlined in O’Connell (2004). The estimation of living stature is determined for adult individuals using the mathematical method of Trotter and Gleser (1952; 1958) and Trotter (1970), who developed regression formulae for European and Black individuals of both sexes. They undertook an analysis of the remains of war victims of known identity from World War II and the Korean War, the statures of whom had been measured on various occasions throughout their lives in the army. In addition, the statures of cadavers of both sexes were measured by the Washington University School of Medicine. Following the

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donation of the skeletons of the individuals to the Terry Anatomical Collection of the Smithsonian Institution, Washington, their remains were then available for long bone measurement (Trotter 1970, 72). The most accurate estimations of stature are derived from measurements obtained from the long bones of the lower limb, with the combined femur-tibia formula generally providing the most accurate estimation. Brothwell and Zakrzewski (2004) provide a useful overview of metrical and non-metrical data that should routinely be recorded from archaeological skeletons since it has the potential to provide information on ethnic affinity, the presence of families within cemetery groups and regional microevolution. Palaeopathology is a vital component of osteoarchaeological research and is particularly essential when employing a biocultural approach. Palaeopathological conditions generally encountered among archaeological human remains can be classified into one of the following categories–developmental, traumatic, infectious, joint, endocrine, metabolic, neoplastic and dental. A number of general text books exist which provide details of the physical characteristics of lesions caused by particular disease processes, as well as the history of particular diseases (e.g. Ortner and Putschar 1985; Roberts and Manchester 1995; Aufderheide and Rodríguez-Martin 1998). Recently, Roberts and Connell (2004) have provided an essential guide to recording palaeopathological lesions; the adoption of their recommendations should enable greater comparability between assemblages from different periods and a variety of geographical regions. A substantial component of Ireland’s prehistoric burials is represented by cremated deposits, particularly during the

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Bronze Age. The potential information to be derived from cremated material is well understood (e.g. Buckley and Buckley 1999), and a useful synthesis of the analysis that should be undertaken on such material can be found in McKinley (2004).

Why Study Irish Human Remains? The objective of this section of the paper is not to provide a comprehensive review of the findings derived from all analyses of archaeological human skeletal remains in Ireland recovered to date. Rather, it is intended to provide an insight as to why such analyses are important for furthering our understanding of the human past within an Irish context. As such, a number of the main lines of evidence that can be informed particularly well by data derived from human skeletal remains have been selected for discussion and will be illustrated with examples from Ireland.

Palaeodemography As discussed above the determination of an individual’s age-at-death and sex (for older subadults and adults) are a routine aspect of the analysis of human skeletal remains. In a normal pre-industrial population group one would expect a high level of infant mortality followed by a notable decline in the mortality of children as they mostly survived to adulthood. It would then be anticipated that the number of older individuals dying would gradually decrease since most individuals died before reaching such an age (Welinder 1979, 83; Waldron 1994, 23). Brothwell (1981, 73) has indicated that the proportion of infant burials expected within a normal pre-industrial population should be approximately 50%.

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When population groups are encountered that markedly deviate from this anticipated age-at-death profile one has to assume that there is a cultural reason for this difference. Within Ireland there is one class of burial ground which invariably produces a deviant age-at-death profile–the cillín or children’s burial ground. Cilliní were the designated resting places for stillborn and unbaptised children who were considered unsuitable for burial in consecrated ground. Although traditionally associated with the burial of unbaptised infants, oral history has also identified the mentally disabled, strangers, the shipwrecked, criminals, famine victims, and people who had committed suicide as individuals who would also be buried within cilliní (e.g. Hamlin and Foley 1983, 43; Donnelly et al. 1999). Locations for this class of burial ground were diverse and included deserted churches and graveyards; archaeological sites including megalithic tombs, secular earthworks and castles; natural landmarks and boundary ditches; sea or lake shores and cross-roads (Ó Súilleabháin 1939). An underlying assumption in much of the literature associated with cilliní is that the separate burial of individuals within a cillín is associated with a lack of regard for these individuals. A recent study of the oral history and anthropological accounts of women who would have experienced the death of baby in early modern Ireland, however, has shown that this is absolutely not the case with regard to the majority of children interred within a cillín (Murphy forthcoming; Murphy and Donnelly forthcoming). In recent years a number of cillín population groups have been analysed by osteoarchaeologists. A total of 62 late nineteenth and early twentieth century burials recovered adjacent to a series of enclosures at Johnstown, Co. Meath,

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were found to comprise almost exclusively young infants (Fibiger 2005a, 101–2). Excavations within the secular tower-house of Castle Carra, Co. Antrim, produced the remains of some 20 young infants, a number of whom appear to have definitely been premature, and a 1.5 to 2.5 year old child. The burials are considered to have been post-sixteenth century in date (Hurl and Murphy 1996; Murphy 2004b). Post-Medieval burials at the Early Christian monastic site of Illaunloughan, Co. Kerry, were found to comprise 112 individuals, 102 of whom were identified as having an age-at-death less than 16 years. It is notable that some 79.2% (76/96) of the precisely aged subadults had died at less than two years of age (Buckley 2005a, 50–1). It is evident that the majority of individuals recovered from excavated cilliní to date have been young infants, although older children and adults are also represented but in smaller numbers. It is feasible that these latter individuals may have included famine victims, criminals and the mentally disabled, amongst others, as discussed above. Indeed, Murphy (1996) has described a possible case of hydrocephalus in a 6–7 year old child recovered from the probable cillín site at Doonbought, Co. Antrim. It can be suggested that this child may have displayed some of the characteristics apparent in modern children with this condition, including headaches, irritability, retarded mental development, loss of balance and an inability to concentrate (Murphy 1996, 440). It is therefore, possible that the child had been buried within the cillín as a direct result of his/her disability. Crombie (1990, 56) recounts a story which might also provide an explanation for the occurrence of older children within a cillín. The last burial in the cillín at Carrownaseer North, Co. Galway, was reported to have occurred during the 1940s when the present landowner’s

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baby brother was buried within the cillín. The baby had been baptised and hence was eligible for burial within a consecrated graveyard. The cillín was located just across the road from the family home, however, and the parents chose to bury their dead baby there so that they could be close to him. It has been proposed that since the cillín was situated adjacent to an early church site this may have further added to its appropriateness for the burial of the baby (Crombie 1990, 56). Deviance from the expected sex ratio of 1:1 in a population (Waldron 1994, 23) can also require comment and a search for a cultural explanation. Of the 56 adults of determinable sex recovered from the Early Christian burial ground at Portmuck, Co. Antrim, 83.9% were found to have been male. As such, the sex ratio of males to females of 5.2:1 identified at Portmuck is clearly anomalous (Murphy 2006). A male-female sex ratio of approximately 10:1 was identified for the individuals interred at the Early Christian site of Gallen Priory, Co. Offaly. It is know that the burial ground at the latter site was used for the interment of the monks who would have lived at the associated priory (Howells 1941, 113). The Early Christian burial ground at Portmuck does not have such clear ecclesiastical associations, although it is known to have been used as a grange for the Cistercian foundation at Inch Abbey during Medieval times (Gwynn and Hadcock 1988, 144). Nevertheless, the notable preponderance of males within the site’s Early Christian horizons may be providing a tantalizing glimpse of an even earlier association with male ecclesiastical activities.

Health and disease

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The study of archaeological skeletal populations can provide an enormous amount of information concerning past health and the diseases that people would have suffered from. Irish populations have produced much evidence for the more common palaeopathological conditions (cf. Roberts and Cox 2003, 30) within the categories of dental, joint, metabolic and infectious diseases as well as traumatic lesions. In addition, examples of less common conditions, such as malignant neoplasms, have also been identified. Murphy (2006) has described a 35–45 year old adult male from the Early Medieval burial ground at Portmuck, Co. Antrim, for example, with osteoblastic lesions that may be indicative of metastatic carcinoma secondary to a primary tumour of the prostate. The following section of the article will provide examples that have been selected for discussion since they illustrate the value of palaeopathological findings for archaeologists and palaeopathologists alike.

Diffuse Idiopathic Skeletal Hyperostosis (DISH) Buckley (2005b) provided a review of four cases of probable or definite DISH (diffuse idiopathic skeletal hyperostosis) that she had identified amongst Irish skeletons. These comprised a Bronze Age older adult male from Graney West, Co. Kildare (probable); a thirteenth-fourteenth century older male recovered from the Dominican Priory at Drogheda, Co. Louth (definite); a thirteenth-fourteenth century older male from St. Stephen’s leprosarium in Dublin (definite) and a Medieval older male from St. Thomas’ Abbey, Dublin (definite). More recently, Murphy (2006) has identified a

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possible case of the early stages of DISH in a 35–45 year old male retrieved from the Early Christian burial ground at Portmuck, Co. Antrim. The main features of DISH involve the ossification of the anterior longitudinal spinal ligament and the development of extraspinal enthesopathies (Rogers and Waldron 1995, 48). The condition is identified in the spine on the basis of the occurrence of flowing calcification and ossification along the anterolateral aspect of at least four contiguous vertebral bodies, the maintenance of intervertebral disc height, and the absence of ankylosis of the apophyseal joints (Resnick and Niwayama 1995a, 1465). DISH generally occurs in older individuals; a reflection of the length of time required before the spinal abnormalities progress to the degree whereby the diagnosis of DISH is easily identifiable (Resnick and Niwayama 1995a, 1466). Males are more frequently affected by DISH than females, and it is thought to be related to obesity and adult-onset diabetes (Crubézy 1990, 116). The clinical symptoms of DISH involve stiffness, restricted movement and back pain (Resnick and Niwayama 1995a, 1466). Due to its associations with obesity and adult-onset diabetes DISH is a condition which may have dietary connotations and be suggestive of the consumption of a rich diet. It is interesting to note that all five of the definite or tentative cases of DISH from Ireland have originated from older males. The burial context of the individuals may also shed further light on their status in society. Two of the individuals originated from sites with definite religious associations–the Dominican Priory, Drogheda, and St. Thomas’ Church, Dublin, while we have already seen that the high preponderance of males at the Early Christian burial ground at Portmuck, Co. Antrim, may be an indication of

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ecclesiastical links. In addition, Medieval leprosaria were frequently associated with ecclesiastical orders (Lee 1996, 14) and it is possible that the individual recovered from St. Stephen’s Hospital in Dublin was a member of a religious order. In a survey of the prevalence of DISH in Britain, Roberts and Cox (2003, 246) have demonstrated that there is a much greater frequency of DISH in monastic sites relative to their secular counterparts, and that the difference is statistically significant. A similar trend would appear to be emerging for Ireland. These British and Irish trends appear to provide an indication that members of certain religious orders lived a more sedentary lifestyle and consumed a richer diet than their secular counterparts. Following a similar line of thought, Buckley (1997) has suggested that the Bronze Age individual with possible DISH recovered from Graney West may have been a leader or sage within that society.

Specific Infections Leprosy and tuberculosis are two of the best known specific infections encountered in the archaeological record. Both diseases are caused by mycobacteria–Mycobacterium leprae for leprosy and mostly Mycobacterium tuberculosis or Mycobacterium bovis for tuberculosis. Unfortunately, the palaeopathology of these specific infections is poorly understood within an Irish context and only a very small number of accounts of possible cases of these diseases have been reported in the published literature.

LEPROSY

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Leprosy is a chronic specific infectious disease which can have a devastating affect on the body, depending on the immune status of the affected individual, and can result in lesions of the skin, nasal tissues, peripheral nerves and bone (Aufderheide and Rodríguez-Martin 1998, 141). Leprosy appears to have peaked during Medieval times in Europe (Roberts and Manchester 1995, 148). In Britain there was a great increase in the number of leprosy hospitals built during the twelfth and thirteenth centuries followed by a notable downtrend, so that by the fifteenth and sixteenth centuries very few new foundations are recorded (Roberts 1986, 16–18). This trend has been explained as a consequence of the emergence of tuberculosis as a highly prevalent disease during Later Medieval times. As stated above, tuberculosis is also caused by mycobacteria and it is considered that exposure to tuberculosis may confer a degree of immunity to leprosy, thereby reducing an individual’s likelihood of contracting this disease. It has thus been suggested that leprosy declined in prevalence as the number of cases of tuberculosis increased during the Later Medieval period (Manchester 1991). Within an Irish context, however, the development and decline of leprosy remains somewhat poorly understood. Murphy and Manchester (2002) have provided an overview of the evidence for leprosy in Ireland. In addition to providing a summary of the secondary evidence for the disease in the form of leprosaria, squints, place-name evidence and historical accounts pertaining to the disease they describe the only definitive case of leprosy to have been published for Ireland. Changes indicative of leprosy were clearly evident in a pair of feet recovered during excavations at Armoy, Co. Antrim; none of the other bones of the skeleton had been

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recovered during the excavations (Fig. 4.3). Dorsal tarsal exostoses were present on several of the tarsal bones, and are an indication of a loss of motor function which leads to the collapse of the longitudinal arch of the foot and the development of pes planus or flat foot (Andersen and Manchester 1988, 52). Surface inflammatory pitting was visible on the dorsal and plantar surfaces of most tarsals and metatarsals and was characteristic of overlying soft tissue infection. Diaphyseal remodelling, in which the medio-lateral diameter was diminished, was apparent in all metatarsals causing them to have a ‘sucked candy’ appearance and a number of their proximal ends displayed the ‘knife edge deformity’. It has been suggested that diaphyseal remodelling occurs as a result of sympathetic neuropathy and alteration of the peripheral nerve vascular bed dynamics which then selectively stimulates extracortical osteoclastic and endosteal osteoblastic reactions (Andersen et al. 1992, 211). The only phalanx present was the right first proximal phalanx which displayed the ‘cup and peg’ deformity of the first metatarsophalangeal joint.

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Figure 4.3: Feet recovered from the excavation at Armoy, Co. Antrim, with lesions characteristic of lepromatous leprosy (Photo: T. Corey). Since the bone changes were so advanced in both feet it is possible that the individual would have been suffering from the lepromatous form of leprosy, which affects people with low immunity to the disease. In addition, the severity of the bone changes in the feet make it quite possible that he or she would have displayed the characteristic changes of facies leprosa, with a collapsed nose, missing upper front teeth, loss

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of eyebrows, and nodules. It is possible that the disease would have progressed to a stage were the person was also hoarse and blind. It is likely that their hands would have had mere stumps for fingers, as was certainly the case with regard to the toes. Their feet and lower legs would probably have had ulcers, which they could not feel due to their damaged nerves. As a consequence of this as they went about their everyday existence they would have been picking up a variety of infections in these open sores. The Armoy case was recovered from a site with no known associations with leprosy. A calibrated AMS radiocarbon date obtained for the feet indicated that the individual had died at some time between 1444 and 1636 cal. AD. The presence of this apparently isolated case of Late Medieval/early Post-Medieval leprosy is considered to be compatible with the history of the disease, however, since it is unlikely that there would have been any thriving leprosaria and associated cemeteries in existence at this time. It has therefore been proposed that the few existing leprosy sufferers would have been buried in the same cemeteries as everyone else (Murphy and Manchester 2002, 196–7). But what of leprosy in Ireland during the twelfth and thirteenth centuries? Why are we not seeing an increase in palaeopathological cases from these centuries in a similar manner to other parts of Europe? Roberts and Cox (2003, 270) have outlined the potential problems involved with identifying leprosy in archaeological human remains. In addition to the fact that some 85% of individuals with the disease probably died before any skeletal changes became apparent, well excavated and well preserved remains are required for a diagnosis of leprosy to be made. The small bones of the hands and feet and the facial area of the cranium are critical for an accurate identification of the

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disease. They make reference to Cox and Bell’s (1999) study which has indicated that phalanges are recovered in less than 40% of skeletons excavated in England. Is it the case that poor preservation is largely responsible for the paucity of leprosy in the palaeopathological record for Ireland? All that was preserved of the Armoy leprosy sufferer was his/her feet. Murphy (2006) has tentatively identified two individuals with possible leprous lesions from the Early Christian burial ground at Portmuck, Co. Antrim. Unfortunately, in both cases the incomplete nature of the individuals’ remains, however, precludes a more definitive identification of the disease. The left proximal phalanges and a single first distal foot phalanx from Skeleton 174, a 35–45 year old male, displayed concentric diaphyseal remodeling and destruction of the distal articular surfaces. Periosteal reactive new bone formation was also apparent in the individual’s left femur and it is possible that the infection of the upper leg may have arisen as a consequence of the infectious processes that were occurring in the feet. A right fifth metatarsal recovered in association with the remains of Skeleton 193, a 35–45 year old male, is considered to display knife-edge deformity of its shaft in addition to a healed fracture at the distal end of the shaft. Both of these changes are compatible with a diagnosis of leprosy. The remains of this latter individual were extremely incomplete and disturbed, however, and it is even impossible to ascertain if the metatarsal had really originated from Skeleton 193 or if it had originally been associated with an entirely different individual altogether. There remains much to be learned about the archaeology of leprosy within Ireland, both in terms of its prevalence in the osteoarchaeological record and in our

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understanding of the secondary sources of evidence relating to the disease (Murphy 2005).

TUBERCULOSIS Tuberculosis can either be an acute or chronic disease and it can involve both the soft and the skeletal tissues (Aufderheide and Rodríguez-Martín 1998, 118). If the primary site of infection fails to heal the tubercle bacilli may be disseminated haematogenously to other organs and tissues. Organ tuberculosis may not become apparent for years after the initial infection and it is exacerbated by incidents, such as malnutrition or trauma, which reduce the resistance of the infected individual. In the notable majority of cases skeletal tuberculosis occurs as a result of haematogenous dissemination from soft-tissue foci (Ortner and Putschar 1985, 141). The bone changes of tuberculosis are essentially osteomyelitic, and the distribution of such bone changes throughout the body is usually the evidence for the disease identified by palaeopathologists (Roberts and Manchester 1995, 137). The tubercle bacteria in the bloodstream select areas of the body which are rich in marrow and have a high circulatory and metabolic rate, such as areas of cancellous bone. In adults the metaphyses and epiphyses of the long bones are predilected and, since haemopoietic marrow has a greater distribution in children, more bones can be involved in younger individuals (Ortner and Putschar 1985, 144). The vertebral column is involved in 25–60% of all cases of skeletal tuberculosis (Resnick and Niwayama 1995b, 2463). Tuberculosis of the spine displays several characteristics 160

depending on the virulence of the bacteria and the resistance of the individuals. In general, only a few vertebrae are involved and marked bone destruction occurs as a result of abscess formation. The vertebral bodies are almost exclusively involved (Morse 1967, 249), while the lower thoracic and upper lumbar vertebrae are the most common sites for the disease (Roberts and Buikstra 2003, 94). The most serious complication of spinal tuberculosis is that of spinal cord compression caused by the sudden collapse of the vertebral bodies, resulting in angular kyphosis (Finch and Ball 1991, 216), which is generally referred to as Pott’s Disease. Tuberculosis can also affect joints, resulting in septic arthritis with gross bone destruction and eventual ankylosis of the joint. As opposed to degenerative joint disease, the tuberculous involvement normally only affects a single joint in an individual. Excluding the spine, the regions of the hip joint and the knee joint are the most frequently affected areas of the skeleton (Roberts and Buikstra 2003, 96–7). The occurrence of plaques of woven bone, cortical expansion, or erosive lesions on the head and neck of a rib (all of which are commonly referred to as rib lesions) have been interpreted as non-specific indicators of chronic respiratory disease stress, including pulmonary tuberculosis (Roberts et al. 1998; Matos and Santos 2006). At least two probable cases of tuberculosis have been reported in the palaeopathological literature for Ireland. A 35–45 year old female (Sk. C753a) recovered during excavations at the Early Christian cemetery of Solar, Co. Antrim, displayed a number of lesions that were considered characteristic of tuberculosis (Murphy 1994). An erosive

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lesion, which measured some 39 mm medio-laterally by 33 mm supero-inferiorly, was present at the glabella region of the frontal bone and extended onto the superior aspects of the nasal bones and the medial margins of the orbits (Fig. 4.4). The lesion had destroyed the external table of the cranial vault and the surviving bone surface displayed a notably pitted appearance. It was considered probable that the lesion was indicative of Lupus vulgaris (tuberculosis of the skin). This condition generally begins before the age of 20 years and persists all through life. The nose, cheeks, brow and sides of the neck are the most commonly affected regions of the body. The skin becomes thickened and discoloured, with the appearance of nodules, ulcers and small abscesses (Macpherson 1992, 347). If it is persistent for a number of years it can cause substantial deformities and it is quite possible that the woman from Solar would have suffered from quite pronounced disfiguration of her brow and possibly nose.

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Figure 4.4: An erosive lesion on the frontal bone of a 35–45 year old female from Solar, Co. Antrim, which is thought to be indicative of lupus vulgaris or tuberculosis of the skin (Photo: E. Murphy). The individual’s ribs also displayed lesions considered to be compatible with a diagnosis of tuberculosis. At least five right and four left ribs were affected. A combination of blastic and lytic lesions were apparent on the visceral surfaces of the rib shafts, although the latter lesions were particularly extensive and had resulted in the inferior margins of the ribs having a pronounced scalloped appearance. A lack of spinal lesions in addition to the morphology of the lesions would tend to suggest they had arisen as a consequence of the blood-born spread of the infection from elsewhere in the body. It is also possible, however, that the rib lesions had resulted from the direct extension of the disease from the adjacent lungs, pleura or chest-wall lymphatic system (Mays et al. 2002, 27–8). A circular lytic lesion, with a diameter of approximately 11 mm, was evident on the medial epicondyle of the left humerus. The elbow is frequently involved in skeletal tuberculosis, with the initial lesion developing in the humerus (Aufderheide and Rodríguez-Martin 1998, 140). As such, it is quite possible this lesion was also related to tuberculosis. A seventeenth-century young adult male (Burial 13) recovered during excavations at St. Stephen’s leprosarium, Dublin, displayed lesions compatible with tuberculosis although it was suggested that a diagnosis of actinomycosis should also be considered (Buckley and Hayden 2002, 167). At least six thoracic vertebrae displayed abscess cavities which opened onto the antero-lateral aspects of the bodies. A

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number of ribs displayed healed periosteal lesions, with destruction of the head and neck area having been evident in one rib. A metacarpo-phalangeal joint from the left hand displayed notable destruction of the articular surfaces (Buckley and Hayden 2002, 166–7). Definite cases of tuberculosis have been identified in the palaeopathological record for Britain as far back as the Roman period. The number of cases identified within the palaeopathological record for Britain increases during the Medieval period, but its prevalence is still small-scale (Roberts and Buikstra 2003, 132–44). A gauge for the presence of the disease in Medieval and Early Modern times is the belief commonly held that the monarchy, as God’s Annointed, were imbued with supernatural powers of healing which were particularly effective for the treatment of the ulcerating lesions of tuberculous infection of the lymph nodes or scrofula. The monarch would touch the afflicted person, make a sign of the cross over them and give them a gold coin (Bloch 1973, 21 as quoted in Aufderheide and Rodríguez-Martín 1998, 128–9). As a result of this practice, tuberculosis commonly became referred to as the King or Queen’s Evil. The records of British gold coin payment indicate a relatively constant but low payment of coins from the eleventh century through to the sixteenth century, followed by a sharp increase in the early part of the seventeenth century from around 300 to 9000 annual payments (Ackerknecht 1972, 103 as quoted in Aufderheide and Rodríguez-Martín 1998, 129). It is generally believed that the demographic shift of people from dispersed rural settlements into overcrowded towns, in addition to the creation of unhygienic urban dairies, were largely responsible for this apparent explosion in tuberculous infection

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(Aufderheide and Rodríguez-Martín 1998, 129). By the early nineteenth century the annual tuberculosis mortality rate in Britain had peaked at approximately 400–500 deaths per 100,000 members of the population, making tuberculosis the most common cause of death by a single disease (Aufderheide and Rodríguez-Martín 1998, 130). There are too few published cases of tuberculosis within the Irish palaeopathological record for trends to be observed concerning the epidemiology of the disease. In more recent documentary accounts, however, it would appear to be the case that the increase in prevalence of tuberculosis that occurred in Britain and many other parts of Europe had also occurred within Ireland. Eighteenth-century Irish newspapers advertise medicines which cure diseases, including ‘the King’s Evil’ and ‘phthisis’. A single spoonful of the pectoral essence devised by Dr. Ryan of Cope Street, Dublin, allegedly cured Captain Peter McLoughlin of ‘galloping consumption with profuse bloodstained sputum’ (Fleetwood 1983, 111–12). Professor Henry MacCormac, a native of Co. Armagh and the Chair of Medicine in School of Medicine of the Royal Belfast Academical Institution, was a recognised specialist in tuberculosis. In 1855 he published a book entitled On the Nature of Consumption, in which he advocated the use of fresh air for the treatment of the disease. This approach became widely accepted as a means of combating the disease across the world, with the use of sanatoria designed to allow the patients access to clean, fresh air; it should be noted, however, that it was initially viewed as a waste of time by many of MacCormac’s contemporary doctors in England who criticised his work (Fleetwood 1983, 190)!

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Mortality from tuberculosis was lower in Ireland during the 1860s and 1870s compared to England, Scotland and Wales, but levels of the disease steadily rose during the 1880s and 1890s. Ireland was one of the few developed countries in which death from tuberculosis was continuing to rise at the turn of the twentieth century. It was only during the 1950s that the rate of mortality from tuberculosis in Ireland had fallen to levels similar to those in other developed countries (Jones 2001, 2–3). Greta Jones has argued that the nineteenth and twentieth century tuberculosis epidemic in Ireland arose as a consequence of economic development. For Belfast and its hinterland she believes that industrialisation was responsible, whereas for Dublin she considers commercial rather than industrial development to have been the cause (Jones 2001, 82).

Medicine Past medical treatments are generally poorly understood for Ireland although we do have some tantalising glimpses of medical intervention becoming apparent in the osteoarchaeological record for the Medieval period onwards. Trepanation–the removal of a roundel of bone from the cranium–is one of the most frequently identified surgical procedures within the archaeological record (Lisowski 1967, 653). Five forms of trepanation have been identified in archaeological human remains throughout the world. The trepanation can be undertaken by scraping (possibly using a piece of flint or a shell), gouging, boring and sawing (using a drill-like implement), sawing alone, and (those in which a small perforation is created) by using a drill (trephination) (Culebras 1993, 11). Lisowski (1967, 659) has summarised

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the motives behind trepanation operations into three categories. The operations may have been undertaken for a therapeutic reason to treat head injuries including fractures and scalp wounds. The trepanation could also have been carried out for magico-therapeutic motives whereby the cause of symptoms, such as headaches, neuralgia or epilepsy, may have been regarded as a consequence of possession by evil spirits. The third of Lisowski’s categories of motivation is magico-ritual, in which the trepanation was undertaken purely for ritual or magical purposes. Ó Donnabháin (2003) had undertaken a recent survey of the evidence for trepanations and pseudotrepanations within the archaeological record for Ireland. One particularly impressive example of a Medieval trepanation, that was clearly undertaken within the context of surgical intervention, originated from the Church of St. Michael-Le-Pole in Dublin. The procedure had been undertaken on an adult left parietal, on the area directly overlying a branch of the middle meningeal artery, and an oval-shaped piece of bone had been detached. The perforation had cut through part of a linear depressed fracture, which appeared to have been caused by a blow from an implement with a blunt edge. Ó Donnabháin (2003, 85) postulated that the trepanation had been undertaken to alleviate symptoms that may have been arisen as a consequence of the traumatic injury. Two other features were evident on the ectocranial surface in the vicinity of the perforation–four linear incisions and three shallow, semi-circular grooves. The former were interpreted as having arisen during the cutting of the scalp, while the semi-circular grooves were believed to have been caused by the operator of the trepanation saw having failed to grip the bone during the early stages of the procedure (Ó Donnabháin 2003, 87). No

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signs of healing were apparent and it was concluded that the individual had died shortly after the procedure had taken place, presumably as a consequence of a fatal haemorrhage as a result of damage to the underlying branch of the middle meningeal artery or as a result of an overwhelming infection (Ó Donnabháin 2003, 88). Moving forward in time to the nineteenth century Lynch (2002) has described evidence of medical procedures in the remains of three male individuals recovered from the graveyard associated with the church of St. John the Baptist in Sligo. In two of the cases the entire superior aspect (‘skull cap’) had been detached from the remainder of the cranium using a small, toothed, presumably metal saw. Care appears to have been taken not to damage the underlying brain and the procedures were interpreted as having occurred during the post-mortem examination of the bodies. Curiously, none of the other cut marks that might be expected to arise during the course of a post-mortem examination were apparent in either skeleton (Lynch 2002, 6). A male individual also displayed two circular, intersecting trepanations on his left parietal. The procedure appeared to have been undertaken using a trepanation saw. In a similar manner to the Medieval example described above a number of semi-circular grooves were evident adjacent to the perforations. No evidence of healing was apparent and it was considered probable that the procedures had either taken place just before the patient died or that they represent an attempt to learn how to use a trepanation saw by practicing on the cranium of a cadaver (Lynch 2002, 6). Ó Baoill et al. (2002) reported a clear case of experimental surgery in a male cranium recovered from a Post-Medieval

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horizon at the corner of Hill Street and Waring Street in Belfast. Six circular perforations were visible on the frontal bone, while four were evident on the left parietal and a further example was visible on the right parietal. It was possible to ascertain that the perforations had been made using a trephine (a circular saw with a guiding central pin) since the aperture for the central pin was still visible in one case where the saw had not completely cut through the vault. An elongated opening associated with a perforation at the right coronal suture was interpreted as a botched trephination during which too much pressure had been applied to the cranium. The listings in the Belfast Street Directories of 1807/8 indicate that a number of physicians and surgeons had been living and working in Waring Street, and it was surmised that the cranium may have been used by one of these individuals for practicing trephination, a procedure that would clearly have required great skill to attain successful outcomes for the patients undergoing surgery.

Activity Markers Specific published studies on activity markers within Irish populations are presently lacking. Evidence for one type of habitual behaviour–clay pipe smoking–has been identified in an increasing number of individuals in recent years. Clay pipe smoking would have been a habitual practice for many individuals living in Post-Medieval Ireland, in the wake of the introduction of tobacco from America in the late sixteenth century. A nineteenth century traveller to Ireland recorded with disapproval that all boys and many girls smoked from around 14 years of age onwards. The soothing effects of smoking were seen as beneficial by many doctors who

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prescribed it for all manner of illnesses (Danaher 1967, 66–7). The habit leaves its mark in human remains through the development of a characteristic concave wear pattern which can affect a number of teeth in an individual’s dentition. This phenomenon is known as ‘pipe-smoker’s clench’ and is due to habitual pipe-smoking and the clenching of a clay pipe between the teeth even when it is unlit (Channing and Buckley 1993). Murphy and McLaughlin (2005) provided an overview of the macroscopic and microscopic properties of three cases of pipe-smoker’s clench. Two of the examples had been recovered during excavations at Boho High Cross, Co. Fermanagh. The skull of an adult male, with an age-at-death of 25–35 years recovered from a charnel pit, displayed the characteristic concave wear patterns on his left maxillary central and lateral incisors. An extremely pronounced concave pattern of attrition was evident on the mesial side of a loose left maxillary canine. It is probable that the attrition would also have extended to the adjacent lateral incisor to form a notably pronounced semi-circular area of wear. The third case was particularly interesting since it was apparent in a 25–35 year old female recovered during excavations at Tonybaun cillín, Co. Mayo (Fig. 4.5). The wear had occurred on the maxillary left lateral incisor and canine. Only one concave wear pattern was apparent in the two complete crania discussed above but Channing and Buckley (1993) reported the case of an adult male recovered from Poolbeg Street in Dublin, in which the characteristic concave wear patterns were apparent at three locations in his maxillary dentition–between the right first and second incisors, the right canine and first premolar and the left second incisor and canine.

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Figure 4.5: Evidence of pipe-smoker’s clench in the maxillary dentition of a female recovered during excavation at Tonybaun, Co. Mayo (Photo: E. Murphy).

Violence and Warfare As with many geographical regions throughout the world there is much evidence for violence and warfaring practices among human remains from Ireland, particularly those of historical date. The following discussion will focus on a selection of cases for the purposes of illustrating a number of the different manifestations that violence has taken within the archaeological record for Ireland to date.

Individual Cases Within Cemetery Contexts

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It is frequently the case that a normal cemetery population produces evidence for at least one individual who had met a violent death at the hands of another. It is generally impossible to associate such isolated cases to particular violent events but they can still provide us with a substantial amount of information concerning contemporary warfaring practices. Excavation of the burial ground at Johnstown, Co. Meath, produced the remains of some 400 skeletons that dated from AD 400 to 1700. Four Medieval individuals displayed clear evidence of violently induced injuries, and details of three of these cases have been published (Fibiger 2005a; 2005b). A 36–45 year old male displayed a notably large ovoid-shaped blunt force injury, which may have arisen as a result of a blow from the rectangular butt end of a battle axe or the hilt of a sword, on his left anterior parietal and frontal. The margins of the injury were smooth and clear evidence of long standing healing was apparent. The other three individuals did not appear to have survived their violent incidents. A series of eight small transverse cut marks on the anterior aspect of the axis of an adult male indicated that his throat had been cut, possibly by someone positioned behind him, presumably during an ambush or surprise attack (Fibiger 200ba, 7). An 18–25 year old male displayed some 20 sharp force injuries on the bones of his head, neck, right shoulder and left hand. One, particularly large, injury would have sliced through the man’s right eye and cheek in a supero-inferior manner. None of the injuries displayed signs of healing and although the majority were dealt from a posterior position a number of anterior blows were visible. The individual also displayed os acromiale, which has been found in high frequencies among the remains of archers who died on board the Mary Rose ship

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(Stirland 2000, 121) as well as Schmorl’s nodes and degenerative changes of the spine. All of these lesions may be indicative that his back and right shoulder may have been subject to a high level of mechanical stress from an early age. It was postulated that Johnstown individual may have been a professional soldier who died during an organised warfaring event (Fibiger 2005b, 6–7). A particularly poignant case of a Late Medieval/ Post-Medieval individual whose remains displayed evidence of weapon injuries was recovered during excavation at Tonybaun cillín, Co. Mayo (Murphy 2004a). A series of blade injuries were evident in the cranium of a 25–35 year old female. The finding was particularly noteworthy since this individual was heavily pregnant when she died. Unfortunately, the cranium was in a poor state of preservation, with extensive fragmentation and surface erosion, and it is probable that the full extent of the injuries has not been ascertained. Nevertheless, at least three sharp force injuries were identified. An oblique blade injury, which extended for at least 50 mm across the superior aspects of the parietals, was visible. A glancing injury was present on the left side of the occipital adjacent to the external occipital protuberance, while a third possible blade injury was present at the midpoint of the poorly-preserved left parietal. The latter injury appeared to have been dealt by someone positioned in front of the woman, while the preceding injuries seem to have been dealt from above. Perhaps an initial blow had caused the woman to fall to the ground thereby enabling her assailant to deal two further blows while standing above her. No signs of healing were associated with any of the injuries. This case is particularly poignant and vividly illustrates the potential brutality of life in the past. No matter whom she was or what

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she had done to deserve such a violent death, it is clear that this heavily pregnant woman would have been particularly vulnerable and would have been a pathetically easy target for attack.

Mass Burials Fibiger (2003) provided a summary of the injuries apparent in individuals retrieved from two mass graves of seventeenth century date and a number of other burial contexts at Carrickmines Castle, Co. Dublin. The remains of at least 17 individuals aged between three and 45 years of age were recovered from the mass graves. A total of seven of the articulated and one disarticulated fragment of cranium displayed evidence of weapon trauma that appeared to have been made during the peri-mortem period. A further 13 adults and sub-adults, whose remains were in a disarticulated condition, were recovered from a variety of contexts on the site; three of the disarticulated fragments displayed sharp force trauma. None of the injuries identified at Carrickmines displayed evidence of healing. A total of 13 sharp force and a single blunt force injury were identified among the entire crania. The sharp force cranial injuries displayed a variety of alignments and locations which tended to suggest that they had been dealt from a number of different positions–behind, in front, from the side or from above. Two of the post-cranial injuries appeared to have been defence wounds, attained when the victim attempted to shield his/ her face or upper body from attack. Fibiger (2003, 5) concluded that the age and sex profile of the individuals, the nature of their burial context in addition to the types of injuries present was more characteristic of an attack or massacre as opposed to formal

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combat. She related the characteristics of the human remains to historical accounts pertaining to the final destruction of the castle in 1642 that record the indiscriminate killing of men, women and children by English forces.

Disarticulated Remains from Non-cemetery Contexts A human cranium recovered in isolation during excavation of a ditch associated with one of the trians of Medieval Armagh displayed signs of decapitation (Gilmore and Murphy 2001). The cranium was that of a 25–35 year old male and clear evidence of sharp force trauma was visible on its left side. The principal injury appeared to have been caused by a single sweeping blow, and the morphology and direction of the sword cut indicates that it had probably been dealt by an individual positioned to the left of the victim. The damage caused by this blow was more defined towards the back of the cranium, in the region of the left mastoid process and the occipital bone, and a probable terminal fracture was also visible on the left cheek bone. It is possible, therefore, that the weapon had initially impacted on the back of the individual’s head before it swept forward, cutting through the uppermost part of the mandible and the cheek. As a consequence, the man would have been partially decapitated. The absence of the skeleton and the post-mortem loss of half of the maxillary teeth suggest that the individual’s head had become separated from the body at some stage following death. Various explanations have been proposed to explain the occurrence of decapitated individuals in archaeological contexts. It is generally accepted that these individuals would have been decapitated for punitive reasons, as a human sacrifice, or for

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the purposes of obtaining the head of a vanquished enemy as a trophy in warfare. Ó Donnabháin (1995a) has reported disarticulated remains that represented at least four male individuals and were recovered from excavations at Isolde’s Tower and Essex Street West, both of which are located along the Medieval walls of Dublin. The remains comprised fragments of three skulls, cervical vertebrae and parts of a right and left arm from two separate individuals. All three of the crania displayed weapon injuries; the nature of the injuries in two of the cases was characteristic of decapitation. In the case of the decapitation from Isolde’s Tower only the mandible was recovered. This displayed a sharp force trauma at its right gonial angle, suggesting that the blow had been dealt from behind the individual. The second case was retrieved from Essex Street West and the cranium was associated with four cervical vertebrae. A glancing blade injury was visible on the right mastoid process of the cranium and three sharp force injuries were visible on the fourth cervical vertebra, which appear to have resulted in the man’s decapitation. The fatal blow appeared to have been dealt from either in front or from the left side (Ó Donnabháin 1995b, 118). The third cranium was recovered from Isolde’s Tower and displayed a glancing sharp force injury on the right parietal, a possible peri-mortem fracture of the right zygomatic and a fracture of the maxillary right first premolar were apparent (Ó Donnabháin and Cosgrave 1994, 103). These injuries were interpreted as an indication that the man may have been severely beaten prior to his death. The disarticulated nature of the remains, the signs of violence and decapitation and the context of their discovery led to their interpretation as the

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remains of severed heads and limbs from executed individuals that had been displayed on the city walls (Ó Donnabháin 1995a, 14). The presence of a small nick on the inner surface of the lamina of the left side of the atlas of the decapitated individual from Essex Street West was interpreted as possible evidence that the head had been mounted on a sharp instrument. In addition, the occurrence of localised crushing of the external vault during the post-mortem period was considered to be a possible indication that the cranium had been subject to rough treatment during the intervening period between the individual’s decapitation and its final deposition (Ó Donnabháin 1995b, 119). This interpretation finds further support in historical documents and contemporary artistic depictions which indicate that particularly serious offences, including regicide and high treason, carried a sentence of being hung, drawn and quartered. The executed individual’s head and quarters would have been mounted on the city walls and gates (Ó Donnabháin 1995a, 13). The situation with regard to the individual from Armagh is less straightforward to interpret, largely since the cranium has been recovered in isolation from any other human remains. In addition, the sharp force trauma apparent on the cranium appears to have been delivered from the side and since it comprised a single blow it is possible that it was attained during an affray rather than as a consequence of deliberate execution. Nevertheless, the discovery of the cranium in isolation from the remainder of the individual’s skeleton and its recovery from a ditch associated with one of the boundaries of Medieval Armagh does not preclude the possibility that the individual’s head had been displayed following his violent death.

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Diet The morphological analysis of human skeletal remains has the potential to yield much information concerning past diets and economies. This type of analysis is now being increasingly augmented with data derived from the analysis of the carbon and nitrogen isotope composition of an individual’s bones (e.g. Schulting 1998). Power (1993; 1994) undertook two synthesis studies, which included some 1000 individuals, of the health and diet of prehistoric and historic populations from Ireland. One particularly informative aspect of this research was a review of dental caries’ rates across time (Fig. 4.6). The cariogenic qualities of a particular diet are determined by the proportion of readily metabolised carbohydrates it contains. Other variables involved in dietary cariogenicity includes the textures of the foods and the population’s daily pattern of consumption. Clinical studies have indicated that the most cariogenic foodstuffs are those which are sticky in texture, contain high levels of simple sugars and are consumed frequently throughout the day. The presence of foods which have a rough texture, or the existence of abrasive particles in the diet, does not readily promote the development of caries since natural oral cleaning is stimulated (Powell 1985, 314). It is generally found that agriculturists display greater frequencies of carious teeth than non-agriculturists or those relying on mixed economies (Leigh 1925, 195).

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Figure 4.6: Neck caries in the mandibular dentition of a Post-Medieval female retrieved during excavation at Tonybaun, Co. Mayo (Photo: E. Murphy). Power reported that out of 1,534 Neolithic teeth included in the study none were found to have displayed caries, while only 0.7% (5/675) of Bronze Age teeth displayed the lesions. Caries frequencies were notably higher during the succeeding Iron Age (4.4%: 18/414), Early Christian (3.9%: 71/1843) and Medieval (4.2%: 184/4334) periods, although it is interesting that the prevalences remained fairly constant throughout these periods (Power 1993, 10; Power 1994, 101). By the Post-Medieval period the situation appeared to have dramatically changed and the prevalence of caries amongst Irish populations had doubled to 8.7% (59/676) (Power 1994, 101). Power surmised that the Neolithic diet had probably 179

been low in carbohydrates and been largely meat-based, possibly having been derived from a combination of hunting and early animal husbandry. The slightly increased prevalence of caries during the Bronze Age was considered to indicate that cereals had entered the Irish diet during the time, although it is probable that animal husbandry was still the predominant economy (Power 1993, 15). She interpreted the notable increase in prevalence of caries during the Iron Age to Medieval times as an indication of an increased reliance of cereals, a trend which remained fairly constant until Post-Medieval times when the diet quite dramatically became increasingly more cariogenic. She postulated that the diet during the Iron Age, Early Christian and Medieval periods may have been mixed, containing cereals, meats and milk products in almost equal proportions (Power 1994, 101–2). It would appear to be the case that by Post-Medieval times there was a notably greater consumption of cereals or at least a greater consumption of cereals in a sticky, porridge-like form that was conducive to the development of caries.

Conclusions The objective of this paper has been to provide an overview of the study of human osteoarchaeology within an Irish context, in addition to providing an introduction to a number of the main methodologies involved in this analysis at present. The majority of the text, however, has concentrated on why the study of Irish human remains is of importance. A series of themes of interest to osteoarchaeologists, archaeologists and the interested lay person alike have been selected. These case studies have provided an introduction to the huge amount of information concerning past health and disease, medical practices, habitual activities, violence and warfare and diet that can be gained from the study of 180

archaeological human skeletal remains. It is evident that the greatest amount of information can be gained about past populations by adopting a biocultural approach whereby the osteoarchaeological evidence is not studied in isolation but rather in conjunction with the historical and archaeological information relating to a particular site. By using such an approach it is possible, for example, to identify and interpret unusual populations, such as those in cilliní or ecclesiastical burial grounds. Human osteoarchaeology within Ireland is still progressing and there is great potential for the development of collaborative synthesis projects between specialists working on the island. In addition, as more specialised biomolecular techniques, such as aDNA and stable isotope analysis, have developed they have been incorporated into research projects involving Irish skeletal remains. It is envisaged that this type of research will produce many interesting results which will help augment the morphological analyses that have been undertaken on the many 1,000s of archaeological skeletons recovered from excavations on the island to date.

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Acknowledgements I would like to thank Dr. Colm Donnelly, School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, for his comments on an earlier draft of the text. I am also grateful to Prof. Don Brothwell, Department of Archaeology, University of York, for reviewing the paper. Thanks are also due to Ms. Libby Mulqueeny, School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, for preparing Figure 4.1 and Mr. Tony Corey, Environment and Heritage Service, DOE: NI, for taking Figure 4.3.

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5 Mammal Bone Studies from Prehistoric Irish Sites Finbar McCormick

Abstract Our knowledge of the utilisation of mammals in prehistoric Ireland has greatly expanded during the past four decades, especially since the publication of van Wijngaarden-Bakker’s pioneering work on the Beaker material from Newgrange in 1974. This essay summarises the knowledge that has emerged since then spanning the period between the Mesolithic and Iron Age. It also outlines the major gaps that exist in the record, the most obvious being for the Neolithic and Late Iron Age.

Introduction Zooarchaeological studies in Ireland date back to the middle of the nineteenth century but it is only during the last 30 years that standardised methods of quantification, metrical analysis and the recording of ageing data have allowed a more rigorous discipline to emerge. Ireland, however, can lay claim to much pioneering work during the early days of faunal analysis. Molyneaux’s (1697) early deliberation on the remains of the Giant Irish Deer is one of the earliest works to deal with megafaunal extinctions, recognising that extinction

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must have occurred at least on a regional scale. William Wilde’s (1840; 1857–61) articles discussing the animal remains from Lagore Crannog, Co. Meath, and other archaeological sites must be amongst the earliest to deal in a detailed way with zooarchaeological material. More recently, Margaret Jope’s work on faunal material from excavated sites in Counties Antrim and Down during the 1950s are amongst the first zooarchaeological reports to tabulate the faunal remains from excavations and develop a systematic method for estimating the minimum numbers of individuals (e.g. Jope 1954; 1955). The work of A. W. Stelfox and Geraldine Roche, both based in the Natural History division of the National Museum, Dublin, also provides much useful information on faunal material from excavations conducted in Ireland during the middle of the twentieth century. They were especially involved with the material retrieved from the crannog excavations undertaken in Ireland by the Harvard investigations that produced large quantities of material (Roche and Stelfox 1936; Stelfox 1942). Their interests, however, lay more in the zoological rather than the archaeological fields and their reports are of limited value today. This is more than compensated for, however, by the fact that they retained much important material including skulls, complete long bones, and generally the bones of wild species. These are presently curated and available for study in the Natural History Museum collections in Dublin.

Methodology Because of the absence of standardised methods of quantification early reports are of limited value when it comes to inter-site comparisons. Furthermore, many excavation reports pay insufficient attention to site stratigraphy and this, often combined with poor dating, lessens the value of many 199

of the early faunal reports. If any work could be identified to mark the beginning of zooarchaeology in Ireland as a systematic discipline, it must be Louise van Wijngaarden-Bakker’s first report on the material from the Beaker levels at Newgrange, Co. Meath, published in 1974. Since then, a series of reports using standardised methods of recording have greatly contributed to our understanding of the exploitation of animal resources in Ireland’s past. An acceptable faunal report needs to contain some basic information, much of it in tabular form. It should contain tables outlining the main NISP (number of species parts) and MNI (minimum number of individuals) values for the main contexts/phases from the site. The basic ageing data for both tooth eruption and wear, and epiphyseal fusion data must be presented in such a way that it can be used for comparison with other sites. At the very least, a summary of the metrical information should be presented and complete bone dimensions, especially those of the less frequently encountered species, should be recorded individually. A report should also record any palaeopathological lesions and butchery marks encountered.

Animal Exploitation in Prehistoric Ireland The present case study evaluates the nature of animal exploitation in prehistoric Ireland based primarily on the study of faunal material during the last 30 years. Prior to 1970, relatively little was known about the subject and some of the assumptions made were erroneous. The Mesolithic economy, for instance, was believed to have been based primarily on coastal shellfish exploitation, supplemented by fishing, fowling and the occasional exploitation of mammals, especially deer. Major aspects of this model are now known

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to be incorrect. Large oyster middens, for instance, are now known to be a Neolithic phenomenon, while the wild pig was the main component of the Mesolithic meat diet, the red deer being absent from the country. With the exception of a small quantity of Late Mesolithic/Early Neolithic material from Lough Gur, Co. Limerick (O’Shaughnessy forthcoming), there is virtually no faunal data from any early post-Mesolithic settlement sites. While the Neolithic is essentially still a mystery as far as animal exploitation is concerned, we now have an emerging understanding of the livestock economies and meat diets of the Bronze and Iron Ages.

Species Availability The range of mammals available for exploitation on the arrival of humans was extremely limited. Table 5.1 compares the mammals present before, and after, the Younger Dryas Spe c ie s Pre-Younger Dryas approx. 12,000-10,000 BP

Giant Irish Deer Red Deer Arctic Lemming Reindeer

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Bear Stoat Hare Post-Younger Dryas approx. 9000-7000 BP

Wild pig Bear Wild Cat Hare Canis sp. Wood mouse Lynx

Table 5.1: Early Holocene species recorded in Ireland (after van Wijngaarden-Bakker 1989; Woodman et al. 1997).

period. A range of animals disappeared either during the Younger Dryas, when Ireland reverted to sub-arctic conditions, or in the warm period that immediately preceded it. Only the bear and the hare were definitely present both before and in the few millennia post-dating the Younger Dryas. The unspecified canid bones from some Early 202

Mesolithic sites are probably wolf so this species can also be added to the list. Were these few mammal species Late Glacial survivors who colonised Ireland via a land bridge before the Younger Dryas and then managed to survive that cold period? Alternatively, were all the extant animals killed off by the sudden cold period and subsequently introduced to Ireland by humans? If humans are capable of introducing large mammals, such as domesticated cattle, it is just as likely that they were capable of importing large and small wild species, especially as young animals. Even bears could have been imported as there is evidence on continental Europe that they were tamed during the Mesolithic (Chaix et al. 1997). The wild pig was the principal species hunted in Mesolithic Ireland and as a forest animal it must have been an Early Holocene introduction rather than a Late Glacial relict. Therefore, at present, there is at least a strong possibility that all of Ireland’s mammals are deliberate or accidental human introductions. The range of freshwater fishes was also much more limited than in Britain or continental Europe due to Ireland’s isolation after the last Glaciation when re-colonisation of fresh-water species was not possible (McCormick 1999).

Mesolithic During the first three quarters of the twentieth century a small series of midden sites had produced faunal remains, but the dating of this material was problematic as there was often an overlap with deposits of the Early Neolithic. The first sites to have produced unequivocal Mesolithic faunal material were at Mount Sandel, Co. Londonderry and Lough Boora, Co. Offaly, both of which date to the Earlier Mesolithic (van

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Wijngaarden-Bakker 1989). While only calcified bones survived at both sites, they reflect a general mammalian exploitation strategy that was to persist throughout the Mesolithic. Red deer were absent and the exploitation of terrestrial mammals was almost solely dependent on the wild pig (Table 5.2; Fig. 5.1). Whether or not the animal protein diet was dominated by wild pig, however, is unclear. At both these sites relatively large quantities of fish bone were recovered; trout and eel at inland Lough Boora with a more diverse range, dominated by salmon and eel but also including sea bass and flatfish, having been exploited at Mount Sandel. This wider species list is a refection of the site’s location at the mouth of the River Bann. Smaller quantities of bird were also present at both sites but these seem to have played an incidental role in the sites’ economies. Isotopic analysis of human remains from Late Mesolithic sites on continental Europe (Schulting 1998), and more recently in Scotland, has shown that, on coastal sites at least, maritime resources predominated in the diet (Schulting and Richards 2002). Human remains from Late Mesolithic Ferriter’s Cove, Co. Kerry, show an extremely heavy reliance on maritime resources but analysis of human bone from coastal Rockmarshall, Co. Louth, suggests a much less important role in the diet (Woodman et al. 1999, 142–3).

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Table 5.2: Mammal species from recently excavated Irish Mesolithic sites (after van Wijngaarden-Bakker 1989, 127; McCarthy 1999, 90; McCormick 2004).

Figure 5.1: Distribution of mammal remains from Irish Mesolithic sites based on the data contained in Table 5.2. The canid was from Mount Sandel while the wild cat was from Lough Boora. NB: the possible canids from Lough Boora were excluded from the graph since their identification was not definite. There is little evidence for permanent settlement in Mesolithic Ireland, with the mammal bones found being interpreted as seasonal indicators of occupation. For example, the presence of large numbers of unworn pig milk teeth at Lough Boora has suggested summer occupation, an observation supported by the large numbers of immature eel also present (van Wijngaarden-Bakker 1989, 127, 129). Epiphyseal fusion data 205

of wild pig phalanges at Mount Sandel suggested that the animals were about 18 months of age at time of death. Assuming that birth occurred in May, this suggests winter occupation, a conclusion supported by the presence of the red-throated diver, a species that presently occurs in Ireland only between October and April (van Wijngaarden-Bakker 1985, 72). As previously stated, large quantities of salmon were present at Mount Sandel and van Wijngaarden-Bakker suggests that these reflect the main salmon run in the River Bann in July and August. She concluded that there were two distinct periods of occupation at the site (van Wijngaarden-Bakker 1985, 74–5)–winter occupation was centered mainly on hunting wild pigs, while the summer occupation concentrated on the exploitation of salmon. Pig too predominated on the two Later Mesolithic sites that have recently produced animal bone–Moynagh, Co. Meath (McCormick 2004) and Ferriter’s Cove, Co. Kerry (McCarthy 1999). The assemblage from Moynagh may reflect a degree of specialisation in animal exploitation; despite the site’s lakeside location and optimal waterlogged preservational conditions there was no evidence for the utilisation of fish or bird. Interestingly, fish were also absent from the Late Mesolithic lakeside settlement at Starr Carr, Yorkshire, accompanied by limited evidence of bird exploitation (Frazer and King 1954). It seems that Mesolithic hunters exploited what was easiest to catch and often ignored other resources. Mammalian ageing data at Starr Carr suggests late spring/ summer occupation which is also the best time for exploiting freshwater fish (Frazer and King 1954). Their absence cannot therefore be adequately explained by seasonal unavailability. Zvelebil (1995) has indicated that there is an increased dependence on wild pig in Late Mesolithic Scandinavia and

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suggests there is also evidence for increased management of pigs at this time. It may well be that the Moynagh assemblage, with its restricted range of animals, is reflecting a similar trend (McCormick 2004). The Ferriter’s Cove faunal assemblage, along with the human bone isotopic data, indicates an economy highly dependent on marine resources. A much wider range of fish species were present than at Mount Sandel, reflecting its location directly on the coast. Large quantities of shellfish were also present. Most surprisingly, domesticated cattle and sheep were also present in Late Mesolithic contexts, a cattle tooth providing an uncalibrated date of 5510±70 BP (4500–4180 BC cal. BC) (Schulting 1999, 219). This is the earliest dated domesticated bovine from either Britain or Ireland and it may represent an early, and unsuccessful, attempt to introduce agriculture into Ireland from continental Europe.

Table 5.3: Cattle, caprovine and pig bones from Irish Neolithic Sites (McCormick 1985; 1987; 1988; A. Lynch pers comm.). The Poulnabrone values are provisional and based on a preliminary examination.

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Neolithic Because of the dearth of Neolithic faunal material, very little is known about the exploitation of animals, domesticates or wild, during this period (Table 5.3). The general absence of ditched enclosures and rubbish pits for Neolithic settlement sites has meant that little in the way of domestic refuse has survived. The faunal remains from a Neolithic house at Tankardstown, Co. Limerick (McCormick 1988, 182–4), are typical of the poor quality of such assemblages. The bones were recovered from the foundation trench, were all calcified and tell us little more than that cattle, pig and caprovines were exploited. Caprovine remains predominated. In contrast, caprovines are absent from small samples recovered from Neolithic contexts at Knowth, Co. Meath (McCormick 1997a). However, such samples are too small to produce reliable results. Most of the more extensive Neolithic samples of animal bones come from funerary contexts but such material can be extremely problematical. Many Neolithic tombs remained open, or were reused over a large period of time, and it is often difficult to accurately date faunal material or prove its association with burial ritual. Wild animals often used Neolithic chambers and their cairns as lairs. Bones may therefore represent animals that died in and around the tombs or food that had been brought to the site by carnivores. Many of these problems can only be addressed by the expensive process of radiocarbon dating individual animal bones. Furthermore, much of the material has not been retained. When comprehensive radiocarbon dating of Neolithic funerary faunal remains has been undertaken, as was the case for Point of Cott on Orkney (Barber 1997), it was found that

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animal deposits were often not contemporary with the human deposits in the tomb and were a produce of natural depositional processes. Faunal remains have been found in many Irish funerary monuments, but in most cases it is impossible to ascertain if they are primary deposits or to assign a date to their deposition (McCormick 1986). It is not possible, for instance, to assign dates to any of the large quantity of faunal material recovered from Ballycarty, Co. Kerry (Connolly 1999). The morphology of the Linkardstown tombs, however, did not generally enable secondary access to the burials and the cairns were often sealed with a thick layer of soil. At Ashleypark, Co. Tipperary, the chamber and cairn were sealed with clay in this way and the radiocarbon dates confirmed a Neolithic date for the animal bones (McCormick 1985). Two types of ritual were noted at the site. The first involved the placing of single bones each of cattle, pig and caprovine alongside the human remains, perhaps token deposits of the main livestock species. The second activity is indicated by a larger sample, almost exclusively of mature cattle, found thrown among the cairn stones that sealed the chamber. This could be interpreted as refuse from a meal, or meals, consumed during the sealing process. The deposition of cattle bone during a sealing process was also noted at the court tomb at Goward, Co. Down (Davis and Evans 1933, 104). No animal bone was associated with the primary tomb deposits on this site but the main chamber had been subsequently partially filled with stones and sealed by a dry stone wall that the excavators regarded as having been of the same phase of activity. Associated with the partial filling of the chamber was the deliberate inclusion of a large number of cattle deposits. The excavators note that ‘there were twenty-three in all sometimes

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consisting of one bone, sometimes of a number … it was particularly noticed that none of the bone deposits were crushed by superposed stones, but were carefully laid in the cracks among stones’ (Davis and Evans 1933, 104). Unfortunately, no dating evidence exits for this sealing occurrence. Occasionally, faunal deposits in funerary contexts suggest that the rituals undertaken were similar to those noted outside Ireland. One of the chambers in the dual court tomb at Audleystown, Co. Down, contained cattle teeth and phalanges. If these are of a Neolithic date they may represent ‘head and hoof’ deposits that were common in Britain, Europe and western Asia during early prehistory (Piggott 1962; Ashbee 1970; Robertson-Mackay 1980; Mallory 1981). At Audleystown too, a pig mandible was placed next to that of a human (Collins 1954, plate 5). The placing of pig jaws in chamber entrances has been noted in long barrows in Gloucestershire and Yorkshire in England (McCormick 1986, 38). At Hanging Grimston long barrow several deposits of pig mandibulae were present, one containing at least twenty individuals. Deposits of pig mandibulae are also common in megaliths in Central Europe. In the Lengyel Culture cemetery at Zengovarkony, Hungary, for example, the human skulls of some of the richer inhumation burials appeared to have been replaced with a pig mandible (McCormick 1986, 38). While molluscs are discussed in detail elsewhere (see Murray, this volume) it is perhaps relevant that their use in funerary ritual contexts is considered here. A large oyster shell was included with one of the primary burials (No. 8a) at Poulawack Cairn, Co. Clare (Hencken 1935, 208–9), while two Venus shells accompanied human bone in the

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‘pseudo-megalith’ at Cahirguillamore, Co. Limerick (Hunt 1967, 31). Neither of these are coastal sites, so their inclusion can be accepted as deliberate. More problematic is the presence of approximately 300 limpet and cockle shells, and a whale bone, in the hilltop passage tomb at Loughcrew, Co. Meath, which is nearly 60 km from the nearest coast (Conwell 1873, 51–2). Unfortunately the tomb was much disturbed and included Iron Age and Early Christian artifacts so the date of the marine material cannot now be established. Perhaps the most obscure use of marine shells in a Neolithic burial context is noted at Dalkey Island, Co. Dublin (Liversage 1968, 103–4). On this site some 50 periwinkle shells were found within the brain case of a human burial, dated to ‘2,300 BC, with a standard deviation of 150 years’ (Liversage 1968, 103). The excavator suggests that the shells had been inserted into the skull for ‘superstitious reasons’. The burial was situated within a shell midden but as this comprised mostly limpets, it precludes a natural explanation for the presence of the periwinkles within the cranium. While faunal remains have provided interesting glimpses into burial ritual in Neolithic Ireland, we remain in some ignorance regarding the livestock economy of the period. Neither do we have much metrical information that could inform us about the type of domesticates present. This is especially unfortunate in the case of cattle. The absence of the aurochs would allow study of Early Neolithic cattle without the complication of the potential presence of the wild bovine in faunal assemblages.

Bronze Age

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Bronze Age settlement sites have in recent years produced large assemblages of animal bone. The earliest is the Beaker settlement from around the passage tomb at Newgrange, Co. Meath (van Wijngaarden-Bakker 1986). Two large enclosures–Mooghaun, Co. Clare and Haughey’s Fort, Co. Armagh–furnish material dating to around 1100–1000 BC, while Ballyveelish and Lough Gur, Co. Limerick, Chancellorsland, Co. Tipperary, and the stone fort of Dun Aonghasa, Co. Galway, have produced material dating to the first half of the first millennium BC. The data derived from these sites are summarised in Tables 5.4–5.6, while Figure 5.2 provides an overview of the minimum numbers of individuals of the main domesticates. What is most striking is the very low incidence of wild mammals at any of the sites. The highest frequency of red deer was at Beaker period Newgrange, but even in that instance, deer represent a very low level of exploitation comprising only 0.8% of the fragments total (van Wijngaarden-Bakker 1986, 89). It is presumed that red deer were deliberately reintroduced into Ireland during the Neolithic, but the date at which this occurred cannot as yet be established. It is possible that they were introduced because of the value of antler as a raw material rather than as a source of meat protein. The Newgrange Beaker assemblage also provides the first evidence for the presence of horse in Ireland. Van Wijngaarden-Bakker (1975) has noted that the appearance of the domesticated horse in Western Europe coincides with evidence for Beaker occupation. The potential presence of wild horse, however, can create problems in identifying domesticated horse. Such complications do not exist in Ireland, however, as there is no evidence for horse here since before the last glacial maximum. The few

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references to horse bones that have been found in megalithic tombs are either probably secondary intrusions or mis-identifications. For example, a horse skull fragment from Audleystown, Co. Down, is likely to be associated with the Food Vessel insertions into the tomb (McCormick 1986, 41). A burnt bone pin from Fourknocks passage tomb, Co. Meath, was described by Hartnett (1957, 245) as having been made of a horse metapodial. Examination of the pin by the writer, however, indicates that it is not possible to identify the bone to species level. As such, the present evidence strongly suggests that the horse was introduced into Ireland at the beginning of the Bronze Age (McCormick 2005, 17–19).

Table 5.4: Distribution (%) of main domesticates from Irish Bronze Age sites after McCarthy (forthcoming a), McCormick (1987), McCormick (1991a) and O’Shaughnessy (forthcoming).

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Table 5.5: Fragments and minimum number of individuals (MNI) data from Bronze Age sites (van Wijngaarden-Bakker 1986; Murphy and McCormick 1996; McCormick and Murray 2006). The MNI values from Mooghaun were estimated by combining the MNI values from a large number of relatively small samples but the distribution coincides with the pattern of the largest samples.

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Table 5.6: Fragments and minimum number of individuals (MNI) data from Later Bronze Age sites (McCormick 1987; van Wijngaarden-Bakker 1995*; McCarthy forthcoming a; McCormick and Murphy forthcoming; O’Shaughnessy forthcoming**).

Figure 5.2: Minimum numbers of individuals distributions from Irish Bronze Age sites based on the data contained in Table 5.4. The nature of Bronze Age faunal assemblages indicates that a range of livestock economies were practiced (Table 5.5; Fig. 5.2). In terms of MNI, the animal of principal importance varies greatly, which is perhaps unsurprising in a period that spans nearly two millennia. Pig were dominant at Beaker Newgrange, while sheep/goat predominated at Dún Aonghasa, a cliff-edge site on the island of Inishmore off the coast of County Galway. Cattle were dominant in the two sites from the middle of the period, namely Haughey’s Fort 215

and Mooghaun. In later sites, with the exception of Dún Aonghasa, there tended to be a more balanced livestock economy, with pig and cattle tending to have been of equal importance.

Early Bronze Age The Beaker assemblage from Newgrange lies at the Neolithic/ Bronze Age transition and is characterised by a high incidence of pig. It has been noted that in England, the Early Neolithic is characterised by high numbers of cattle, but that pig became increasingly important towards the end of that period (Grigson 1982). This is particularly notable in henge monuments associated with Grooved Ware pottery. The English evidence is more equivocal at the beginning of the Bronze Age but the largest sample, from Grooved Ware/ Beaker levels at Mount Pleasant, Dorset, shows a continued predominance of pig. It may well be that the Newgrange material is part of this pattern. Grigson (1982, 309) equates the increase in pig at this time to a decline in pastoralism occasioned by a regeneration of woodland and especially bracken which can accompany such regeneration. Pigs can thrive on bracken, but it is poisonous to cattle, sheep and horse. Does the pollen evidence support such an interpretation? The evidence from Redbog, Co. Louth, supports the occurrence of a regeneration of woodland from about 2300 cal. BC to about 1600 cal. BC, when extensive clearance begins again (Weir 1995). While bracken is continually recorded as being present, there are no peaks compared with preceding periods. The high levels of pig at Newgrange can most likely be explained in the context of

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increased woodland, with a decline in available pastureland, more suitable for sheep and cattle. Mount (1994), however, questions the assumption that the faunal assemblage from Newgrange is representative of the livestock economy of the period. He questions the excavator’s interpretation of the settlement as being merely ‘people … squatting in rather flimsy structures’ around the edge of the collapsed cairn of the passage grave (O’Kelly 1989, 73). Instead, Mount regards the faunal material only as an indicator of sporadic ritual activity associated with the Early Bronze Age pit circle excavated by Sweetman (1985). He also regards the English faunal assemblages associated with Late Neolithic henges as being unrepresentative of the contemporary livestock economy. It is quite likely, as Mount argues, that the food refuse was a product of feasting, but there is no reason to believe that the food consumed on such occasions, whether it be ritual or social feasting, should be unrepresentative of the livestock economy in general. It is probable that in most early societies, the ritualistic behavior of feasting is largely a direct consequence of having to deal with the large amount of fresh meat that became available when a domesticated animal was slaughtered (McCormick 2002a). The pigs reared at Newgrange would have been used exclusively used for their meat. Van Wijngaarden-Bakker (1986, 74–5) found that the highest proportion were killed at about 2–2.5 years, but that a significant number were killed at an older age. She concluded that they were a late maturing type. In the case of cattle and sheep from Newgrange (there was no evidence for goat) there was the potential for the production of secondary products. The identification of

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secondary exploitation of domesticates can be based on analysis of the sex ratio and age-slaughter patterns, generally using models outlined by Payne (1973). The main problem with this is that faunal samples often do not provide adequate aging and sexing data. Moreover, as Greenfield (2005) emphasises, mixed livestock strategies rather than specialised secondary produce strategies would probably have been the norm in prehistoric societies. As a result it is likely that early sex ratio and age-slaughter patterns might not conform to Payne’s models. There was an equal balance between male and female cattle at Newgrange, with the peak in slaughter occurring in three and four year olds, with only about 10% of the animals surviving into their fifth year. On the basis of this information, van Wijngaarden-Bakker (1986, 48–51) concluded that the animals were primarily being reared for their meat and that there was no evidence for dairying. This need not mean, however, that they were not milked occasionally since recent isotopic analysis of pottery residues has shown that cattle have been milked in England since the Early Neolithic (Copley et al. 2003). There is no definite evidence for the presence of goat in Ireland by the Beaker period. In her preliminary report on the Newgrange faunal assemblage, van Wijngaarden-Bakker (1974, 77) suggests that two radii could be attributed to goat but withdraws this in her subsequent publication of the assemblage when she stated that ‘no bone could be ascribed with certainty to goat’ (van Wijngaarden-Bakker 1986, 76). The ageing data for sheep at Newgrange was equivocal, suggesting an emphasis on the killing of semi-mature individuals. No data concerning the sex of the individuals is available. The absence of old sheep indicates that the production of wool was unimportant at this time. At present

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there is no evidence, direct or otherwise, for the exploitation for wool in Ireland before the Late Bronze Age. The earliest apparent spindle whorls are from Late Bronze Age Ballyveelish, Co. Tipperary (Cleary et al. 1987, 25) and Ballinderry I, Co. Meath (Hencken 1942, 19), with the earliest wool textile having been found with the Late Bronze Age Cromagh’s hoard, Co. Antrim (Jørgensen 1992, 19).

Late Bronze Age Two Bronze Age hillfort settlements dating to about 1000 BC have produced faunal assemblages–Mooghaun, Co. Clare and Haughey’s Fort, Co. Armagh. The distribution of the main domesticates at the two sites is quite similar, the main difference being that sheep/goat are more important at Mooghaun (Fig. 5.2). This may be explained by the presence of a variety of land use types in the vicinity of Mooghaun, including more marginal raised bog and fenlands (Grogan 1995, 46), and it is possible that these areas were better suited to sheep rather than cattle grazing. Goat were present at both Mooghaun and Haughey’s Fort but in very small numbers. The Mooghaun sample was extremely fragmented and provides little information about the age or sex distribution of the livestock present. Cattle ageing, based on epiphyseal fusion, indicated that the majority (67%) of those long bones that fuse at 42–48 months were fused (McCormick and Murray 2006, 305). This compares with a mere 22% in the case of Newgrange, and marks an apparent shift in slaughter pattern to older cattle, although the extreme fragmentation could be producing a bias in the sample. The Haughey’s Fort data originated in waterlogged contexts and should suffer less

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from taphonomic bias. There, 52% of cattle were in the older age group which again represents a shift towards the exploitation of more mature individuals compared with the situation at Newgrange (Murphy and McCormick 1996, 48). At Haughey’s Fort, a small sample of mandibulae supported the fusion data, with 50% having derived from animals over 40 months at time of death (Murphy and McCormick 1996, 48). The move toward older animals could imply an increasing exploitation of secondary products such as milk. However, Early Christian period age slaughter patterns, which clearly reflect a dairying economy, show a peak in one to two year olds with fewer older animals being present (McCormick 1992). The Later Bronze Age data is therefore not characteristic of a dairying economy. It may well be that these older cattle represent the introduction of traction into Ireland. Van Wijngaarden-Bakker (1986, 96) concluded that there was no evidence for the use of draft oxen at Beaker Newgrange. Furthermore, it is Mitchell and Ryan’s (1997, 234) contention that the plough was introduced into Ireland during the ‘Later Bronze Age’. Unfortunately, there is not enough data from either Mooghaun or Haughey’s Fort to allow the sex ratio of the cattle to be determined. Because pig are single use species their age slaughter pattern tends to be consistent both chronologically and spatially. At Haughey’s Fort, for instance, the peak in slaughter occurred at 2–2.5 years, a similar pattern to that noted at Newgrange. The small amount of data from Mooghaun seems to confirm this pattern. While the great majority of pigs on these sites were domesticates, small numbers of wild pig were noted at Haughey’s Fort. The hunting of wild animals, at this and all sites of the period, was incidental. Sheep numbers were especially low in Haughey’s Fort where, in terms of MNI,

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they were less important than dog. The higher incidence of sheep at Mooghaun, as suggested above, may have been due to environmental factors. There was no artifactual evidence for wool processing having occurred at either site. The horse remains present at Haughey’s Fort were generally derived from old animals, suggesting that they were not slaughtered until they had fulfilled their roles as traction animals. One of the horses at the site displayed spavin which can be caused by heavy traction (Murphy and McCormick 1996, 48). Some metacarpals displayed cut marks that were likely to have been the result of skinning. The breakage of other horse bones may have been for the removal of marrow. The dog population at Haughey’s Fort was characterised by large animals, with shoulder heights of up to 65 cm being recorded. These are amongst the largest known dogs from a prehistoric site in Britain or Ireland at this time (Murphy and McCormick 1996, 49). In contrast to the preceding period, sites from the latest phase of the Bronze Age display a range of economic strategies as noted at Dún Aonghasa, Co. Galway, Lough Gur, Co. Limerick, and Chancellorsland and Ballyveelish, Co. Tipperary (Table 5.6). The development of wool processing could account for the rise in sheep rearing at this time, although environmental factors must at least partially account for the unprecedented high occurrence at Dún Aonghasa. Cattle do not have the clear MNI dominance noted on the earlier hillfort sites; this relative decline would appear to be related to an increased exploitation of sheep. The enclosed habitation sites of Ballyveelish and Chancellorsland, Co. Tipperary (Doody 1987; 1996), indicate little change in pig levels during the latter part of the Bronze Age (Fig. 5.2). At

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Lough Gur, pig were the dominant species but not to the same extent as noted at Beaker period Newgrange. Their high incidence is difficult to explain as there is an absence of palynological evidence for the area at this time. Van Wijngaarden-Bakker (1995, 87–9) notes that a bird bone assemblage from a Late Neolithic/Early Bronze site in the same area suggests an open wetland and rough grassland environment with little evidence for forestation. The high incidence of pig, therefore, might suggest re-forestation during the Later Bronze Age but there is no independent evidence for this. The Dún Aonghasa assemblage is quite different from any of the assemblages so far considered. In virtually all other post-Mesolithic sites wild animals, be they mammals, birds or fish, were either not exploited or were of only incidental importance. In this assemblage, large quantities of fish were present, the species dominated by wrasse and bream (McCarthy forthcoming). The large assemblage of birds present were dominated by guillemot and shag (O’Sullivan forthcoming) and molluscs, characteristic of the rocky shore, were also exploited (O’Connell forthcoming). The mammal assemblage is dominated by sheep, with pigs being found in negligible numbers. Pig constitute about 8% of the MNI total but this is in fact a methodological exaggeration as they constitute only 1% of the identifiable fragments recovered from the site. The low incidence of pig can be attributed to the low incidence of oak on the islands and the fragile nature of the soil cover that would be susceptible to destruction by the rooting habits of pigs (McCormick and Murphy forthcoming). This low incidence of pig is unparalleled in any Irish or British prehistoric site. The high precedence of sheep can usually be attributed to the presence of a strong wool

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trade, rather than wool production on a subsistence level, or the occurrence of extensive cereal cultivation since their manure provides richer fertilizer than cattle. Both Grant (1984, 543) and Cunliffe (1978, 184) have invoked both of these explanations for the high prevalence of sheep during the southern English Iron Age. It is unlikely, however, that either of these factors can account for the large numbers of sheep at Dún Aonghasa. It seems more probable that the high prevalence of sheep is simply due to the hardiness of the species. Sheep can generally endure more extreme weather conditions than cattle, especially during winter, when they can survive on limited fodder. Indeed, shortage of winter fodder was probably the principal constraint for livestock rearing on Late Bronze Age Arran. Hay was not saved in Ireland until the Anglo-Norman period so livestock would have been dependent on the very meagre vegetation that grew throughout the winter.

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Table 5.7: Cattle fusion data from Dún Aonghasa and other Irish prehistoric sites after van Wijngaarden-Bakker (1986), McCormick (1987), Murphy and McCormick (1996), McCormick and Murphy (forthcoming) and O’Shaughnessy (forthcoming). The ageing data is derived from Silver (1969).

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Figure 5.3: Cattle age slaughter patterns based on the data contained in Table 5.7. The marginality of the area is reflected in the age/slaughter patterns of the cattle where there is a high incidence in the slaughter of very young animals. Half of the cattle were slaughtered before the pelvis had fused, which occurs at approximately 7–10 months (Table 5.7; Fig. 5.3). A high juvenile slaughter rate is a feature of coastal sites in the west and north of Scotland for all periods (Noddle 1979), and the Dún Aonghasa material conforms to this pattern. While it can be argued that the slaughter of young animals may reflect a specific livestock rearing regime (Payne 1973), it is more likely in the case of Atlantic sites that the killing of young cattle is a consequence of fodder shortage (McCormick 1998). The slaughter of large numbers of young calves in order to ensure that the remainder had enough fodder for survival is succinctly expressed in the Hebridean proverb ‘Is fearr aon laogh na da chraicionn’–one calf is better then two

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skins (Carmichael 1916, 256). An unusually high juvenile sheep mortality (there were no goat noted at Dún Aonghasa) was also noted, with 56% of the pelves being unfused (Fig. 5.4). Cattle age slaughter/patterns from other Late Bronze Age sites do not show consistent results. The high incidence of mature cattle at Ballyveelish is reminiscent of the pattern noted at Haughey’s Fort but the Chancellorsland assemblage, with its high incidence of juvenile animals, has much more in common with slaughter regimes of the Early Christian period.

Figure 5.4: Sheep age slaughter patterns (McCarthy forthcoming a; McCormick and Murphy forthcoming, based on the method of Silver (1969)). There is ample evidence for the processing of wool during the Late Bronze age after 1000 BC (see above). Despite this, there is still no decisive shift to Payne’s (1973) ageslaughter

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model for wool production, with its predominance of older animals. The peak in sheep slaughter at Chancellorsland is for semi-mature animals, which according to Payne (1973, 281) would suggest that they were primarily raised for meat (Fig. 5.4). There is clear regional and temporal variation in livestock size during the Bronze Age. Figures 5.5–5.7 compare cattle, sheep and pig measurements from different sites. In the case of cattle it can be seen that many of the individuals present at Dún Aonghasa were smaller than those on mainland sites (Fig. 5.5). This can be attributed to environmental factors, with the island being less suitable for breeding cattle than other areas. The same seems to holds true for pig (Fig. 5.6), but is not the case with sheep (Fig. 5.7–it is assumed that all the Dún Aonghasa caprovine remains are of sheep). The sheep from Dún Aonghasa are both larger and smaller than those noted from elsewhere, but admittedly the latter samples are very restricted. If the results are accepted as valid, it implies that the environment of Arran was eminently suitable for the raising of sheep. The cattle from Beaker period Newgrange are extremely large compared with those present on other sites. This finding is unexpected as there appears to have been a general decline in cattle size after domestication. Davis (1987, 178) notes that in England, there is a continual decline in cattle size between the Neolithic and the Iron Age, with Early Bronze Age cattle tending to be smaller than those of the Neolithic. This is not the case in Ireland. The cattle from Newgrange were on average larger than those present in contemporary Late Neolithic/Early Bronze Age Lough Gur and also larger than those from Early Neolithic Ashleypark (McCormick 1997a,

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302). The reasons for this dichotomy are at present unclear and more samples from Neolithic sites are needed in order to provide a possible explanation. Metrical data for pigs is somewhat limited for Irish prehistoric sites. In general, the pigs from Newgrange tend to be larger than later periods, with a gradual decline in size occurring between the Early Bronze Age and the Early Christian period.

Figure 5.5: Cattle size on Bronze Age sites based on astralagus measurements (McCormick unpublished data).

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Figure 5.6: Pig size on Bronze Age sites based on astralagus measurements (McCormick unpublished data).

Figure 5.7: Sheep size on Bronze Age sites based on astralagus measurements (McCormick unpublished data).

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As occurred during the Neolithic, animals continued to be associated with burial ritual during the Bronze Age, but are generally confined to Early Bronze Age single burials. Pig tusks are often included in cist burials, almost invariably in association with Food Vessel pottery (McCormick 1986, 37). There is no clear evidence of joints of meat of a consistent type having been placed with burials, such as the pig shoulder joints that have been noted in some contemporary Scottish burials (McCormick 1991b). Sea shells continue to be deposited with burials. Ritual deposition of animals unassociated with human burials has also been noted; for example, cremated bones of a range of animals were found in the pits of the Early Bronze Age pit circle at Newgrange. The excavator concluded that the pits ‘acted as receptacles for remains of burnt votive offerings’ (Sweetman 1985, 214). Dog bones too are occasionally found in ritual contexts, a few apparently in association with Early Bronze Age burials (McCormick 1986, 40). The Late Bronze Age artificial pond at the King’s Stables, Co. Armagh, contained a curious assemblage of bone (Lynn 1977). In addition to some bones of the main domesticates, it contained unusually high proportions of dog and red deer antler. The pond also contained parts of a human skull. The author favored a ritualistic deposition interpretation for the assemblage.

Iron Age The small number of extant Iron Age assemblages are all from high status ceremonial sites. Navan Fort, Co. Armagh (McCormick 1997b), Tara, Co. Meath (McCormick 2002b) and Dún Ailinne, Co. Kildare (Crabtree 1990), are all identified in the early historical literature as regional capitals but the actual functions of the sites are not always clear. The

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Tara material was derived from the ditch of the large enclosure known as Ráith na Ríg. While the enclosure is of Iron Age date, it enclosed a Neolithic passage grave and two conjoined ‘ringfort’ type monuments, possibly of Early Christian date. The bones consisted of discarded food refuse but it is unclear what sort of habitation activity it reflected. Dún Ailinne was clearly not an ordinary habitation site (Wailes 1990). Morphologically the site is a henge and the large circular and ‘figure of eight’ structures were obviously not dwellings. Wailes (1990, 19) concluded that it was a ceremonial site and the faunal remains may relate to communal activity such as feasting. The Navan material came from the phases that pre-date the massive 40 m ceremonial wooden structure. It is associated with a series of round houses within a palisaded enclosure (Lynn 1997) and the evidence suggests that the occupation was domestic, albeit of high status, as indicated by the artifactual finds present and the occurrence of a Barbary ape skull (Raftery 1994). The similarity of the sites as regional ceremonial centres is not reflected in the faunal assemblages. Pig clearly predominate at Navan Fort, while cattle are the dominant species at Dún Ailinne (Table 5.8). The samples from Tara were small but suggested domination by cattle. The high incidence of pig at Navan cannot be attributed to environmental suitability–i.e. the presence of large-scale oak forests. The livestock economy of nearby Haughey’s Fort is dominated by cattle and the pollen evidence does not indicate any increase in oak forest cover in the intervening period (Weir 1997, 116). Instead, the high incidence of pig can be interpreted as a reflection of the choice of pork as a high status food during the Iron Age. Strabo noted that pork was the favorite food of the Continental Celts (Tierney 1960,

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268), while Ross (1974, 395–6), on the basis of Irish mythology, concluded that pork is the proper food to be served at the feast, in the ritual of hospitality in the courts of kings, and in the dwellings of the gods. If the assemblage at Navan can be explained in the context of the preferred diet of high status Celts, how does one explain the dominance of cattle at Dún Ailinne? While Navan Phase 3 is clearly a domestic habitation site this is not the case with Dún Ailinne. The large figure of eight structure with its funnel entrance and the subsequent circular structure with its standing or seating platforms suggest great ceremonial constructions for massed open-air assemblies. The scale of these would imply social inclusively rather than restriction to a small number of high status individuals. Feasting in this context would therefore not have been confined exclusively to the elite, but instead include the general population where beef, rather than pork, may have been considered a more appropriate food. Cattle ageing data is not available for Navan and the material from Dún Ailinne and Tara is limited. It is, however, clear that the patterns observed at Dún Ailinne and Tara differ greatly. The great majority of cattle killed at Tara are mature individuals (McCormick 2002b, 105), while large numbers of young calves were killed at Dún Ailinne (Crabtree 1990, 23). Crabtree argued that the age slaughter pattern at the latter site represented dairying but McCormick (1991c) did not agree with this interpretation. On the basis of the small samples it is difficult to identify specific cattle raising strategies but it is clear that there is regional variation within Ireland. The pig slaughter pattern noted at Navan, the only site to produce an adequate sample, indicates an age slaughter pattern similar to

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that noted in earlier periods. There is no useful data available for sheep; the species is generally much less important than either cattle or pig during the Irish Iron Age. This contrasts greatly with southern England at this time where sheep were the dominant species on the majority of sites (Hambleton 1999).

Table 5.8: Fragments and minimum numbers of individuals distribution from Iron Age sites (Crabtree 1990; McCormick 1997; McCormick 2002b). NB: The sample from Tara was too small to allow reliable calculation of MNI values. Although horse was present in Ireland since the Beaker period they occur in very small quantities during the Bronze Age (see above). They are absent from Dún Aonghasa and Chancellorsland and only a few fragments were noted at both Haughey’s Fort and Lough Gur. The high incidence of horse fragments at Ballyveelish was exceptional, but most fragments were teeth and they represented only a single individual from the two main contexts on the site. The incidence of horse increased greatly during the Iron Age, and is perhaps a reflection of the development of wheeled vehicles as evidenced by the Doogarymore wheels which date 233

to the Late Bronze Age/Early Iron Age transition (Raftery 1994, 104). At Dún Ailinne and Tara, horse remains comprise 2.5% and 5.5% of the fragments’ totals respectively. The horse remains are interspersed with other discarded food refuse so it must therefore be concluded that horse flesh was being consumed. Some of the bones from Tara displayed butchery marks and in one instance the bone displayed evidence of roasting. Dog bones from Tara also displayed butchering marks. It is possible that the high incidence of horse bones at Tara may derive from rituals associated with kingship (McCormick 2005, 21–2). The consumption of dog flesh may too have ritualistic associations (Bhreathnach 2002, 118–20; McCormick 2002b, 107). The complete horse long bones from Tara provide us with the first evidence of horse shoulder heights in Ireland. They are from animals with estimated withers’ heights of 130 cm and 133 cm, i.e. 13–14 hands (McCormick 2002b, 107), comparable in size to the modern Connemara pony. The association of animal bones with burial ritual continues during the Iron Age but to a lesser extent than previous times. Only a small number of Iron Age burials are known from Ireland, mostly consisting of low mounds or ring barrows. These generally contain cremations in pits either within the mound or under it but inhumations also occur. When animal bones are present, their role in the burial ritual is generally unclear. At Furness, Co. Kildare, the matrix of the mound contained a scattered assemblage of animal bones which included cattle, sheep/goat, pig and horse, together with several disarticulated human bones (Grogan 1984, 305). No animal bones, however, were noted with the pit cremation burials on the site. There are several instances of Iron Age, or

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possible Iron Age, burials where the association between the faunal remains and the human burials are more likely to be accidental (McCormick 1986, 46; Buckley et al. 2002). It can be concluded that animal deposition did not play an important role in burial ritual at this time and indeed with the arrival of Christianity, the inclusion of grave goods of any type became theologically unacceptable, although exceptions could be made in special circumstances. A twelfth century document records that the father of Dermait Mac Murchada was buried with a dog as a mark of ‘hatred and contempt’ (Fry 1999, 107).

Conclusions Faunal studies undertaken during the last 30 years have greatly increased our understanding of how animals were exploited in prehistoric Ireland. There are large gaps in our knowledge but a framework now exists for prioritising areas of future research. The Irish Mesolithic, uniquely in western Europe, was dominated by the exploitation of wild pig, an animal that had the potential to become domesticated. A genetic study is presently being undertaken to establish if early Irish domestic pigs are derived from the native stock or, instead, were being imported as part of a Neolithic ‘package’. Is the dominance of pig noted at Beaker period Newgrange a continuation of a Neolithic livestock economy that was dominated by pig rearing? Neolithic domestic assemblages are needed to answer this fundamental question. The Bronze Age is characterised by considerable variation in livestock rearing strategies across Ireland. These are likely to reflect localised needs and traditions adaptations and contrast greatly with the Early Christian period where a country-wide livestock economy based on dairying developed. The Iron Age assemblages come from contexts that are probably 235

unrepresentative of the general livestock economies of the period. Crucially, assemblages are needed from the first half of the first millennium AD which will allow us to further investigation the origins of the livestock economy that is so well documented during the Early Christian period.

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6 Exploitation of Birds and Fish in Historic Ireland: A Brief Review of the Evidence Sheila Hamilton-Dyer

Abstract Documentary sources have often been used to examine the role of birds and fish in Ireland, but this evidence has been rarely backed up by archaeological data, until relatively recently. In recent years several major excavations have been undertaken which have produced animal bone assemblages of significant size. Bird and fish remains have formed a minor, but important, component and where sieving has been employed it has become clear that fish in particular have been under-represented in assemblages. This brief survey of recent work on some major assemblages serves to indicate the potential for further work. There are consistent patterns beginning to emerge despite problems of sample size, preservation, and retrieval bias. The suggestion from early research that urban sites are mainly exploiting domestic poultry and large, offshore, fish in a similar manner to Britain and much of Europe is confirmed. Distinct differences between assemblages of Early Christian and Anglo-Norman sites are becoming evident. High status

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Anglo-Norman sites may also offer rarities from feasting and falconry. Early Christian sites on the west coast show an exploitation of a large variety of local marine fish and birds. There is, therefore, great potential for future analysis of well stratified and, preferably, sieved material and there are notable areas for which evidence is lacking, primarily the low status rural sites and inland sites in general. Research has already shown several discrepancies between the documentary and archaeological evidence for the Medieval period, while research on the introduction and past distribution of species is also a subject area of great potential within an Irish context.

Introduction The analysis of faunal remains from early excavations of archaeological sites in Ireland was rarely undertaken. Excavations were often limited in research design and analysis of animal remains, if they were collected at all, was carried out without the benefit of recent work on stratigraphy, sampling, and taphonomy. Reports concentrated on mammal bones with scant regard to birds and fish, while collection policies did not take into account the special methodologies required for the successful collection of small and fragile bird and fish bones. It is clear that such bones are usually poorly represented in early reports although, it should be stated that the bird bone report produced for the excavation at Lagore Crannog, Co. Meath (Stelfox 1938), was extraordinarily good for its day. Reports on fish remains were almost non-existent, although the remains of cod and Ballan wrasse were recovered from excavations at Church Island, Valencia, Co. Kerry, during the 1950s (Roche 1958).

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It has been difficult to assess the reasons for the paucity of bird and fish without reference to collections of good size and adequate phasing from more recent excavations; earlier work can be used with only limited confidence. This review of the current state of research has been restricted to the historic period, in part because this addresses most of the faunal assemblages studied in recent years. The largest bird and fish bone collections have been mainly recovered during excavations of Medieval and Post-Medieval urban centres; collections from Early Christian sites are rarer, although many coastal sites are now producing good samples. Bird and fish bones are especially rare on Irish prehistoric sites. Newgrange, Co. Meath, for example, could offer only a few bones of goshawk from secure contexts (van Wijngaarden-Bakker 1986a). It has been difficult to assess whether this reflects a lack of exploitation or if the situation has arisen as a consequence of recovery bias. Major assemblages from prehistoric sites, especially in the south and west of Ireland, are now being excavated and analysed (McCarthy 2000), however, and must await future publication. Excavation of the Mesolithic sites at Mount Sandel, Co. Londonderry, and Lough Boora, Co. Offaly, provided an opportunity to analyse and compare remains of bird and fish in addition to those of mammals (van Wijngaarden-Bakker 1986b; 1989). Woodpigeon, salmonids and eels were found to have dominated these assemblages. At Ferriter’s Cove, Co. Kerry (McCarthy 1999), fish bones formed the major components of the vertebrate remains. The sampling and sieving strategy employed at the site was a crucial factor in the retrieval of this important assemblage, which included many remains of relatively small fish such as wrasse, whiting, and young of the larger Gadidae.

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Documentary evidence, such as that summarised in the seminal work by Kelly (1997), is often selective, biased in favour of status and legal matters, and rarely representative of the archaeological situation, which mainly relates to the daily routine of the bulk of the populace. References to fish, for example, mostly concern salmon and the use of weirs (Kelly 1997, 287, 291) yet most archaeological assemblages are dominated by marine fish. It is important not to ignore documentary evidence, however, since an interpretation of domestic fowl bones as having been purely a source of food, for example, is misleading. In the past these birds were frequently held in high regard for divination and other symbolic reasons and analysts should be aware of possible alternative interpretations when such remains are recovered during an excavation. Written sources may also provide information about material that is not normally preserved in the ground, such as bird feathers (Kelly 1997, 362). Documents and illustrations may also provide information relating to the method of capture of fish and wild birds by nets and snares, for example, where direct evidence is lacking. The original design of this paper had been to produce a gazetteer of Medieval and Post-Medieval sites in Ireland that had produced bird and fish remains, but it soon became apparent that many sites had produced only very small collections of such bones. These small assemblages are inadequate for the provision of more than an unrepresentative species list and fish remains, in particular, are rarely recovered without sieving, a practice which has become routine on many Irish excavations only very recently. Fortunately, several of the more recent excavations have produced sieved bone collections comprising thousands of

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specimens and these, and other significant assemblages, are discussed below.

Methodological and Taphonomic Considerations Retrieval bias is probably the one single major factor affecting archaeological bird and, especially, fish bone assemblages. The question of sampling policies for the retrieval of small bones is crucial; although many bird bones can be hand collected the smaller skeletal elements and bones of the smaller species are usually missed. In the case of fish bone this situation includes many of the more important species–herring and eel bones rarely exceed a few millimetres and even large fish have relatively small elements. The cartilaginous sharks and rays are often represented on archaeological sites only by teeth and dermal denticles, which are generally of extremely small size. As such, it is only possible to suggest that certain species were probably unimportant when extensive sieving has been carried out on a site. Even then absence is never certain, however, and allowance must be made for factors which may have resulted in differential survival. Salmon, for example, have a reduced level of calcium in the skeleton of breeding fish making the run upriver–just at the most favourable time for capture–and as a consequence their bones tend to decay easily. The structure of fish bones in general can also mitigate against their survival as they have a laminar, even filigree, construction that easily allows percolation of destructive chemicals and mechanical damage (Wheeler and Jones 1989, 62; Jones 1999). In addition, where aggressive soil conditions (e.g. acidic sands) are present all bones will be adversely affected to some degree, but bird and fish bones will suffer proportionally greater loss, simply on account of their small 251

size. Sample size is also of great importance; the major mammals exploited usually dominate the assemblage and are of a small number of taxa. In contrast, fish and bird bones are usually a minor component of assemblages, with just a few bones each of a wide range of taxa. As a result the smaller the sample the less likely any particular species will be encountered. The problems discussed by Maltby (1997), who undertook a comparative survey of domestic fowl remains from Romano-British sites in England, are equally relevant here. The recovery method, sample size, and the variations between workers concerning identification criteria, recording and quantification methods must all be taken into consideration when attempting inter-site comparisons. Retrieval bias in bird bones can be illustrated, for example, by plotting the relative proportions of small and large skeletal elements recovered. Standardisation of analytical procedures can also help with inter-site comparisons; the methodology should state, for example, whether or not unidentified material has been included or excluded, and if all skeletal elements are recorded. Problems arising from differences in identification and recording techniques can be eliminated for many of the fish assemblages listed in the current account since the remains have been analysed by just two specialists who employed similar methodologies. When dealing with a large number of possible species in conjunction with the necessity for time-consuming microscope work it can be tempting to restrict the recording process. Unlike the situation for mammals and, to a certain extent birds, it is difficult to reduce the amount of essential recording for fish remains. It is not usually appropriate to record a limited set of elements since fish vary enormously in skeletal conformation and number of

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bones; this can also lead to differential preservation of the same element in different species. Furthermore, certain elements are family or even species exclusive–dermal denticles in rays and pharyngeal bones in wrasse and cyprinids–while some fish–lampreys, sharks and rays –have no true bones at all. As such, direct quantification and comparison with other faunal material is fraught with difficulties. Access to extensive comparative reference collections is also essential for bird and fish bone analysis, even more than is the case with research on mammal bones. The question may be asked, why commit resources to the costly and time-consuming detailed analysis of bird and fish bones if they are rarely recovered and form only a tiny part of the bone assemblage compared to the main domestic mammals? There are a number of compelling reasons why this analysis should be routinely undertaken. At some sites, especially those located along a coast, the exploitation of fish and birds would have made a major impact on the diet and lifestyle of the inhabitants. The remains may also offer seasonal information, such as the summer exploitation of local fish inferred from the bird and fish remains recovered from Mesolithic contexts at Ferriter’s Cove, Co. Kerry. Taphonomic bias, particularly for fish, almost certainly produces a gross underestimate of the quantity originally present. Although meat-weights are obviously much less for each individual fish than for the main domestic animals such as cattle, the sheer numbers–both of bones in the skeleton and of individuals consumed–increase the contribution significantly. Birds and fish can provide variety of taste in the diet in addition to supplying a plethora of proteins, vitamins and

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minerals (e.g. iodine and Vitamin A from fish). Cultural practices and differing lifestyles may be hinted at where they would not be revealed by the ubiquitous, almost universal, base of the domestic mammals. Seasonal activities can be indicated by the recovery of the remains, for example, of guillemot chicks or corncrakes. Possible status differences can be inferred by the presence of high status fish such as salmon. The recovery of imported species, such as peacock, pheasant and pike, can also provide insights concerning status. Reliance on documentary sources alone has been shown to be completely inadequate but there are notable areas for which archaeological evidence is also lacking, particularly with regard to the smaller species. The presence of birds of different species within an archaeological assemblage can also provide information about the nature of the local environment. The availability of seabirds at Illaunloughan, Co. Kerry, provided information about local island colonies (O’Sullivan 2005), for example, although this interpretation must be tempered by the knowledge that bird remains from cultural deposits in general predominantly represent deliberately exploited taxa such as poultry or those regarded as pests such as buzzard and crow. The remains of birds that lived in the vicinity of a site, but were neither eaten nor culled for other reasons, would be rarely recovered from refuse deposits. This situation would appear to be especially true for smaller birds such as the common ‘garden’ songbirds; their remains are rarely recovered even on sites where extensive sieving has been undertaken. Ireland has a restricted fauna, mostly due to its separation from Britain (and therefore also mainland Europe), by the Late Glacial opening of the Irish Sea. Birds were obviously less affected than land mammals, although some birds such as

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woodpeckers do not seem to have reached Ireland. Some bird species appear to have been formerly present or even common, such as eagle, raven, crane and capercaillie, but are now rare or absent, while others such as pheasant have been introduced. The freshwater fish found in Ireland today were almost all introduced, probably by the Anglo-Normans and later groups. Mapping the arrival and departure of the Irish fauna in the archaeological record has been explored by van Wijngaarden-Bakker (1985). A further examination of the distribution of a limited selection of birds was recently undertaken (Yalden and Carthy 2004), but nothing similar has been further attempted for fish.

The Evidence: Birds Bird bones are very rarely recovered in large numbers from excavations but most sites, even those which have not employed sieving, produce a few. In some assemblages they form a significant minor component, and hand collected material generally displays a bias against the smaller species and body parts. The small passerines (songbirds) are often particularly affected but smaller game birds, waders, and pigeons can also suffer, and it is noticeable how few have been recovered from unsieved sites. A checklist of species recovered from historic contexts in Ireland is provided in Table 6.1, while the distribution of species at the major sites included in the current study is displayed in Table 6.2. Few assemblages from major Early Christian inland sites have been recovered to date, and those retrieved from early excavations have rarely been quantified. The assemblage retrieved from the excavations undertaken at Lagore Crannog, Co. Meath (Stelfox 1938), during the 1930s is exceptional and, although excavated by hand as opposed to having been

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sieved, the species list is extensive. Over 30 taxa were identified using a reference collection of modern skeletons and, although a few identifications may be over enthusiastic, the list and quantities are plausible. Wild species dominated, with geese, swans, water birds, raptors, and ravens having been common, while domestic fowl were present but not at a high level. Other, smaller assemblages too small and/or too old display a similar trend but, as one would expect, these hand collected bones are mainly from larger species. Documentary sources suggest that all kinds of birds were captured by nets, traps and missiles for food (Kelly 1997, 298–302). Raptors in pre-Norman assemblages mainly represent culls of pests. Corvids may have been kept as pets (Kelly 1997, 129), but they are also carrion feeders and predators of young poultry and may have been culled as vermin. Domestic fowl are frequently mentioned in law texts, manuscripts and poetry (Kelly 1997, 102). This galliform bird is a native of Asia and, although fragmentary material can be difficult to separate from grouse species, in Ireland it is generally accepted that galliform bones are those of the introduced domestic fowl. Relative to their reference within the literary sources domestic fowl bones are rare on Irish Early Christian sites, despite being present in England from the Late Iron Age. Their very rarity may have conferred special status on the bird, thereby providing an explanation for the documentary interest. The presence of both male and female domestic fowl, as evidenced by the recovery of spurs and sometimes by medullary bone, implies that they were bred, although they may have been kept mainly for eggs and cock-fighting rather than primarily for eating.

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Bird bone assemblages recovered during excavations at coastal fort sites are unfortunately small, and almost all were excavated over 40 years ago. The remains of seabirds have been found in all of the assemblages and it is probable that they were exploited for eggs as well as flesh. More substantial samples have been recovered from monastic sites located along the Atlantic seaboard although, again, many were excavated some time ago and have only produced small and unsieved assemblages. In general, the results would tend to suggest that seabirds and geese were of major importance. Of the more recent excavations Illaunloughan, Co. Kerry, produced a large assemblage dominated by Manx shearwater, a species still common on the west coast (O’Sullivan 2005). The exploitation of seabirds in Scotland is well known (Serjeantson 1988), and these ground nesting birds and their eggs were undoubtedly used for food, perhaps also preserved for later use. These and other fish-eating seabirds were also classed as ‘fish’ and therefore would have been permissible fare during times of religious fasting. divers, Gavia sp.

quail, Coturnix coturnix

great crested grebe, Podiceps cristatus

turkey, Meleagris gallopavo

little grebe, dabchick, Tachybaptus ruficollis

crane, Grus grus

fulmar, Fulmarus glacialis

coot, Fulica atra

corncrake, Crex crex

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Manx shearwater, Puffinus puffinus

waders, Charadriidae, including plovers

gannet, Sula bassana cormorant, Phalacrocorax carbo

Pluvialis sp., cf. lapwing, Vanellus vanellus, cf. oystercatcher, Haematopus

shag, Phalacrocorax aristotelis

ostralegus, woodcock, Scolopax rusticola,

heron, Ardea cinerea

snipe, Gallinago gallinago, curlew,

swans, Cygnus sp.

Numenius arquata, bar-tailed godwit,

domestic goose or greylag, Anser anser

Limosa lapponica, and cf. greenshank,

other grey geese, Anser sp. probably

Tringa nebularia

white-fronted, A. albifrons

gulls, Lariidae, including cf. great black-

Brent goose, Branta branta

backed, Larus marinus, herring/lesser

barnacle goose, Branta bernicla

black-backed, L. argentatus/fuscus, and

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domestic duck or mallard, Anas platyrhynchos

common/kittiwake, L. canus/Rissa tridactyla

other ducks, including cf. wigeon Anas

guillemot, Uria aalge

penelope, cf. teal, Anas crecca, cf.

razorbill, Alca torda

garganey, Anas querquedula, and cf.

pigeons, cf. woodpigeon, Columba

tufted, Aythya fuligula

palumbus, and domestic/ rock dove,

white-tailed eagle, Haliaeetus albicilla

Columba livia

osprey, Pandion haliaetus

raven, Corvus corax

kite, Milvus sp.

other Corvidae, cf. crow, Corvus corone,

goshawk, Accipiter gentilis

or rook, Corvus frugilegus, jay, Garrulus

buzzard, Buteo buteo harrier, Circus sp.

glandarius, cf. jackdaw, Corvus monedula, and cf. magpie, Pica pica

peregrine falcon, Falco peregrinus

Small passerines, cf. blackbird, Turdus

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capercaillie, Tetrao urogallus

merula, cf. thrush, Turdus philomelos, cf.

domestic fowl, Gallus gallus

fieldfare, T. pilaris, cf. redwing, T.

pheasant, Phasianus colchicus

iliacus, and cf. starling, Sturnus vulgaris,

partridge, Perdix perdix

finches, Fringillidae

Table 6.1: Birds identified from Medieval Post-Medieval sites in Ireland, in taxonomic order.

and

Domestic fowl appear to have become frequent for the first time in Viking levels at Fishamble Street, Dublin (O’Sullivan 1990). Geese were present but they were not as common as fowl. It is difficult to separate the very similar species of grey geese but at least three of these species, and the smaller Brent geese, were present. As was the case for Early Christian period sites the raptors were common and the white-tailed eagle, the kite, osprey, harriers and the buzzard were all present. These birds can be considered as scavengers and vermin species, but the eagle also had symbolic importance in Viking mythology. Raven remains occurred frequently in both Early Christian and rural assemblages, although they were particularly numerous in Viking deposits from Dublin, and it is possible to speculate that this situation may have arisen as a consequence of the mythological association of the bird with the Viking god Woden.

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Table 6.2: Distribution of bird taxa at selected Irish sites. Sources: (1) Hamilton-Dyer (in prep.); (2) Stelfox (1938); (3) Monk (1984); (4) O’Sullivan (2005); (5) Hamilton-Dyer (2002); (6) Hamilton-Dyer (2004a); (7) McCarthy (2003); (8) O’Sullivan (1990); (9) Hamilton-Dyer (1993); (10)

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Hamilton-Dyer (1996); (11) Hamilton-Dyer (1997a); (12) Hamilton-Dyer (1999a); (13) Hamilton-Dyer (2000a); (14) Hamilton-Dyer (1997b); (15) Hamilton-Dyer (1999b). Waterbirds include–divers, grebes, heron, coot, moorhen. Gulls and seabirds include–all gulls, shearwater, puffin, gannet, guillemot. Hawks and falcons include–buzzard, kite, goshawk, harriers, peregrine. NB: for Fishamble St., Dublin, all geese have been grouped in the wild category as all four species, including greylag, were considered wild.

By the thirteenth century, the character of bird bone assemblages recovered from Dublin had changed markedly, with a restricted list of species and an increased number of goose remains. As indicated above, it is difficult to distinguish between the different species of geese and the situation is further complicated if domestic birds are thought to be present; the ancestral greylag goose is a common resident and will mix with domestic birds. Human selection during the domestication of geese, whether deliberate or unconscious, appears to favour heavier birds with smaller wings and thicker legs (Reichstein and Pieper 1986). Measurements derived from the substantial collection of goose bones recovered from Anglo-Norman deposits during excavations at Arran Quay, Dublin, appear to support this assertion as these too would have had sturdy leg bones and shorter wing bones in comparison with wild birds (Hutton Macdonald et al. 1993). The increase in frequency of geese in the thirteenth century material is, therefore, thought to have been due to the introduction of domestic birds by Anglo-Norman settlers. In comparison with the Early Christian Irish sites there is a consistency amongst the later urban assemblages, such as those recovered from Dublin, Galway, and Cork (McCarthy 2003), of a striking predominance of domestic poultry. Along with domestic fowl and goose there was often increased numbers of mallard-sized duck and some of these may well have been the domestic

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form. This trend has also been observed in other Anglo-Norman assemblages; at many of these sites domestic poultry frequently account for over 80% of the identified bird bones (Table 6.2). In contrast, sites with little Anglo-Norman influence appear to continue the earlier pattern. At thirteenth-fourteenth century Lough Gur, Co. Limerick, for example, poultry amounts to only 10% of the identified bird bones (Monk 1984). Similar differences occur in the distribution of waterbirds and waders; common but not particularly tasty waterbirds such as gulls, cormorant and heron occur sporadically across the sites, as do swans and the now absent crane. The waders, however, have only been commonly found at Later Medieval sites; this situation also applies to the few native game birds found–quail, partridge and capercaillie. This turkey-sized grouse is now absent from Ireland and it has been disputed as an Irish native (D’Arcy 1999, 99). Its first appearance in Irish archaeological material was in Mesolithic deposits at Mount Sandel, Co. Londonderry (van Wijngaarden-Bakker 1985). Recently capercaillie remains have been identified in Medieval material from Trim Castle, Co. Meath (Hamilton-Dyer 1997b), Carrickfergus, Co. Antrim (Hamilton-Dyer 1999b), Galway (Hamilton-Dyer 2004a) and Wexford (McCarthy n.d.). Jope (1954) also stated that capercaillie bones were recovered from the excavations at Clough Castle, Co. Down. It has been suggested that capercaillie may have been the ‘wood-peacock’ noted by Giraldus Cambrensis, a remarkably observant Medieval ‘travel writer’ (Kelly 1997, 300). Three non-native members of this order are noteworthy in the Irish context, i.e. pheasant, peacock and turkey. Pheasant bones have been positively identified from Anglo-Norman deposits at Trim Castle, Co. Meath (Hamilton-Dyer 1997b); the

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earliest evidence for its introduction to Ireland retrieved to date. Osteologically, the pheasant is extremely similar to domestic fowl and it is therefore possible that its remains may have been overlooked in some assemblages, although it is unlikely to have been common until recently. Peacock bones have yet to be identified in Irish assemblages, but it is mentioned as being present on demesnes in the south-east by the late thirteenth century (Down 1987, 478). Locations which have produced Post-Medieval bird bone material include Dublin (Hamilton-Dyer 1997a), Carrickfergus (Hamilton-Dyer 1999b) and Galway (Hamilton-Dyer 2004a), and the assemblages from all three urban centres have included turkey bones. This bird is a native of America and these findings are, therefore, consistent with a Post-Medieval introduction to Ireland. The bird bone assemblage recovered during excavations in Galway was sufficiently large to enable a metrical analysis to have been undertaken on the fowl bones. An increase in size was detected between the Medieval and Post-Medieval periods, perhaps indicating improvements in husbandry and breeding or the use of new types (Hamilton-Dyer 2004a). Dovecotes date from the Anglo-Norman period and pigeon bones have been found at a number of sites. The small number of pigeon bones recovered from Early Christian sites have been identified as woodpigeon, whereas almost all of the pigeon remains retrieved from Medieval sites, such as the castles of Trim and Maynooth, have been smaller in size and comparable with domestic pigeon (the ancestral rock dove is native to Britain but is uncommon (Reid-Henry and Harrison 1988)). Pigeon bones recovered from Trim Castle, Co. Meath, were mainly derived from young birds and in one case

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evidenced the axial division of the carcass (Hamilton-Dyer 1997b). Another interesting group of birds recovered from Irish assemblages of historic date are the raptors. Most of these birds are scavengers, or they will take poultry and pigeons. There seems to have been no interest in hunting with birds in Ireland until the Anglo-Norman period and the raptor remains recovered from Early Christian sites almost certainly represent culls of vermin (Kelly 1997, 303). Many of these species, such as buzzard, kite and harriers, are unsuitable for falconry. Direct evidence for falconry is also absent from the later sites (e.g. Trim and Maynooth Castles) since raptor bones are rare compared with those of poultry and only the chick-taking buzzard has been identified to date. The tiny bones of quail were identified in Medieval levels at Trim Castle, Co. Meath, while those of the now rare corncrake have been found at Lagore Crannog, Co. Meath (Stelfox 1938), Clonmacnoise, Co. Offaly (Hamilton-Dyer in prep.) and Dundrum Castle, Co. Dublin (Hamilton-Dyer 1999a). These species are of interest because they are entirely migratory, arriving from Africa in early summer. The remains of such birds are unlikely to be recovered in the absence of on site sieving. The interpretation of small passerine bones remains a problem even if they are recovered since, unless butchery or other evidence is clearly indicative of their consumption, they may represent the remains of birds that had lived on the site or were brought there by cats. Trim Castle, Co. Meath, is the only assemblage thus far to have produced a substantial number of passerine bones; these were mainly derived from the thrush family and they appear to have been consumed as

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evidenced by butchery marks, anatomical selection and their association with other probable food waste (Hamilton-Dyer 1997b).

The Evidence: Fish Collections of fish bones are now available from a variety of different types of site from throughout Ireland. The nature of these assemblages, however, is extremely variable and they can range in size from a single bone to many thousands. As stated above, sieving is particularly important for the retrieval of archaeological fish remains since most fish bones are too small for easy hand collection and many are microscopic. Work is currently in progress on several major samples that have been sieved. A checklist of fish species recovered from historic contexts in Ireland is provided in Table 6.3, while the distribution of species at the major sites included in the current study is displayed in Table 6.4. The most notable aspect of all Irish fish bone assemblages is the presence of marine, rather than freshwater species. Indeed, at only one site–the inland Early Christian monastic site of Clonmacnoise, Co. Offaly–can all the fish be interpreted as having come from the river. Even this interpretation could be in doubt, however, as they are all migratory species–eel, salmon and shad (Hamilton-Dyer in prep.). As such, it is extremely interesting to note that the documentary sources so often used in discussions of diet and faunal exploitation almost exclusively make reference to freshwater fish (Kelly 1997). Salmon is often referred to in the texts but is uncommon in archaeological material in comparison with other species. This situation may partly have arisen as a result of taphonomic bias, due to the nature of fish physiology and bone structure as noted above. It is also possible, however,

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that the freshwater salmon had evoked greater interest among writers since it may have been considered a higher status fish relative to its more freely available marine counterparts. The collections of fish bone material available to date are mainly derived from the major Medieval urban centres, such as Dublin, Cork and Galway, and Early Christian sites from the west coast. The only inland sites to have produced fish bone are the Early Christian monastic site at Clonmacnoise, Co. Offaly (Hamilton-Dyer in prep.), and the Medieval rural castles of Trim, Co. Meath (Hamilton-Dyer 1997b), and Maynooth, Co. Kildare (Hamilton-Dyer 2000a). It should be noted, however, that the latter two sites are both located less than one day’s travel from the Dublin Bay coast. sharks and rays unspecified

cod family, Gadidae, unidentified

spurdog, Squalus acanthias

fragments and rocklings

thornback ray, Raja clavata

gurnards, Triglidae, probably

ray unspecified

mostly grey, Eutrigla gurnardus

conger eel, Conger conger

sea scorpion, Taurulus bubalis

eel, Anguilla anguilla

bass, Dicentrarchus labrax

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herring, Clupea harengus

scad, Trachurus trachurus

shad, probably twaite, Alosa

seabreams, Sparidae including

fallax

red seabream, Pagrus pagrus,

salmonids, cf. salmon, Salmo

black seabream, Spondyliosoma

salar, may also include trout,

cantharus and others not further

Salmo trutta

identified

cod, Gadus morhua

grey mullets, Mugillidae

ling, Molva molva

wrasse, Labridae

haddock, Melanogrammus

Ballan wrasse, Labrus bergylta

aeglefinus

mackerel, Scomber scombrus

pollack, Pollachius pollachius

turbot, Scophthalmus maximus

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saithe, Pollachius virens whiting, Merlangius merlangius

halibut, Hippoglossus hippoglossus

pouting, Trisopterus luscus

other flatfish, cf. plaice,

hake, Merlucius merlucius

Platichthys platessa, and flounder, Pleuronectes flessus

Table 6.3: Fish identified from Medieval and Post-Medieval sites in Ireland, in taxonomic order.

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Table 6.4: Distribution of fish taxa at selected Irish sites. Sources: (1) Hamilton-Dyer (in prep.); (2) Hamilton-Dyer (2002); (3) Hammilton-Dyer (2004a); (4) Mc Carthy (2003);

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(5) Hamilton-Dyer(1993); (6) Hamilton-Dyer (1996); (7) Hamilton-Dyer (1997a); (8) Hamilton-Dyer (2000a); (9) Hamilton-Dyer (1997b); (10) Hamilton-Dyer (1999b); (11) Hamilton-Dyer (2005); (12) Hamilton-Dyer (1999c); (13) Hamilton-Dyer (1994a); (14) Hamilton-Dyer (1994b); (15 McCarthy (1997). The Early Christian ecclesiastical coastal site at Illaunloughan, Co. Kerry, already noted as having produced an unusually large quantity of shearwater bones, is also striking because of the sheer number of seabream bones, of more than one species (Hamilton-Dyer 2005). This finding might indicate a preference for these tasty fish, or locally favourable fishing conditions, but it may also be an indication of warm sea conditions. These fish have also been identified in Roman and Medieval material that originated from along the south-west coast of England (Wilkinson 1979), yet until relatively recently they were considered to be uncommon catches. Wrasse bones were also frequent in the Illaunloughan assemblage together with several other species, such as pollack, bass and conger, which also prefer to live near rocky coasts. The secular Early Christian sites of Rathgurreen (Hamilton-Dyer 2002) and Doonloughan (Hamilton-Dyer 1999c) are situated further north along the Atlantic west coast in County Galway. As was the case for Illaunloughan, the assemblage retrieved from Doonloughan produced considerable numbers of inshore species represented in the sieved material, although in this case wrasses and the pelagic scad were more frequent than the seabreams. Only 12 fish bones were recovered from Rathgurreen, which had not been sieved. Two of the bones were from large fish (hake and angler) and nine were of scad from a single find-spot

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(Hamilton-Dyer 2002). It is highly probable that fish were grossly under-represented at the site as a result of the excavation strategy and this situation highlights the problems involved with comparing data derived from sieved and unsieved sites. Trim Castle produced samples of varying sizes which ranged from a hand collected twelfth century assemblage to considerable, and sieved, samples derived from thirteenth-fourteenth century midden deposits. Only a single cod vertebra was recovered from the hand collected sample, while over 14 species were identified in the sieved assemblages. These mainly consisted of Gadidae, flatfish and conger but, importantly, the collection also included three pike bones (see below). Numerous samples, ranging in date from the twelfth to eighteenth centuries, have been recovered from various excavations undertaken in Dublin–Back Lane, Cornmarket, Bridge Street, Arran Quay and Nicholas Street. In general, the fish remains predominantly comprised large Gadidae, including cod, ling, haddock and hake. A number of these fish would have been notably large individuals which are mainly found, and therefore caught, offshore in quite deep water. Ling, for example, is known to favour water depths of 300–400 metres (Wheeler 1978). The haddock bones recovered were found to have included specimens much larger than those generally available today. None of these assemblages were sieved and it could be argued that the apparent bias in favour of large bones was due to the lack of sieving. The apparently genuine nature of this preference for large fish, however, has been confirmed as a result of the examination of more recently excavated assemblages which

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have included sieved material. Although more species were present in these latter samples and the predominance of large fish was not so marked it was still present. Anatomical distribution is also likely to be biased in unsieved collections and it is difficult to judge, for example, whether the low proportions of caudal vertebrae in many of these samples is due to taphonomy or is an indication of butchery processing. The sample recovered from excavations at Arran Quay was particularly biased in favour of cod and ling head bones, a probable indication of the preparation of salted and/ or dried fish (Hamilton-Dyer 2004b, 236). Documentary evidence indicates that preserved fish would have been traded from Dublin (although it could have been imported from elsewhere) (Murray 1999). Medieval and Post-Medieval coastal sites have produced a wider variety of species, mainly wrasse, scad, pollack and seabreams, which can be caught inshore on rocky ground–i.e. locally. Fish bone collections from complimentary sites from other coastal areas, inland and from different settlement types are now needed so that it is possible to fully explore whether this difference is chronological, social or geographic in nature. Interestingly, the recently analysed material from Medieval and Post-medieval deposits in Galway City (Hamilton-Dyer 2004a) has a unique identity which would appear to be more similar in nature to the assemblages derived from eastern urban sites and at variance to material recovered from Early Christian west coast sites. There is a dominance of the large gadids similar to the Dublin assemblages but some of the inshore rocky ground species are also represented. In light of Galway’s location on the west coast of Ireland it can therefore be tentatively proposed that a

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genuine difference in terms of fish exploitation existed between Early Christian and Medieval urban sites. Fish bone assemblages recovered from Medieval and Post-Medieval horizons in Cork have been dominated by hake (McCarthy 1997; 2003). This cod-like fish is now under threat from overfishing (FAO 1997), and the archaeological evidence would tend to suggest that it was more common in the south and west of Ireland (and England) in the past. Several of the fish bone assemblages retrieved during excavations in Cork included sieved material. It is interesting to note that these were the only ones to have produced herring bones. This finding again underlines the need for sieved samples to enable the effective analysis of fish bone assemblages. Conger eel occurs only as a minor component of assemblages, but is a species regularly encountered in small amounts in most Anglo-Norman and later material, including Galway City, Dublin and Trim Castle (Hamilton-Dyer 1993, 1996; 1997b; 2004a). This fish is of interest as it is one of the few marine species to be mentioned in the documentary sources, and inland at that, as there is a record of congers being sent to Clones in the early thirteenth century (Davies and Quinn 1941, 25). The presence of conger eel bones in Medieval assemblages may be a reflection of an Anglo-Norman taste. Cartloads of conger were transported to Salisbury from Southampton, for example (Stevens and Olding 1985), and there is archaeological evidence of split eels (probably salted and dried) in Salisbury itself (Hamilton-Dyer 2000b). Similarly, split eels were also found on the Tudor warship, the Mary Rose (Hamilton-Dyer 1995; Coy and Hamilton-Dyer 2005). A specimen from Maynooth Castle, Co. Kildare, had

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been axially divided in an identical manner to these English examples (Hamilton-Dyer 2000a). Conger was identified at only one of the Early Christian sites–Illaunloughan. Whether this finding is related to favourable conditions for catching conger or some other reason is not clear. As with other faunal classes, Ireland has a restricted list of native freshwater fish. Following the separation from Britain during the Late Glacial it would appear to be the case that only the migratory salmonids, whitefish (pollan), shad, eel and lamprey managed to populate Irish fresh waters. Pike is reputed to have been introduced by the Anglo-Normans and was sufficiently successful to have enabled its export back to Britain by the late fifteenth century (Longfield 1929, 49). On this note mention can be made of the recent finding of pike from late thirteenth-early fourteenth century assemblages at Trim Castle (Hamilton-Dyer 1997b). This is the first case of pike to have been recovered from an Irish archaeological site, but even in this instance it is not impossible that the remains were those of an imported preserved fish. A limited number of Cyprinidae are now present in Ireland but again these were introduced, possibly starting with Anglo-Norman introductions but certainly by the seventeenth century (Longfield 1929). Members of this family include bream, carp, tench, and gudgeon, but no examples of these species have been recovered from secure archaeological contexts in Ireland to date. Mention should also be made of the apparent difference between the Medieval and Post-Medieval urban fish bone assemblages of Ireland and those of contemporary England. Although English sites have produced many bones of the large Gadidae they are often dominated by the remains of

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herring and eel especially in rubbish and cess pits. In this respect the Irish material is more similar to that of Aberdeen and other Scottish sites, which also have produced little herring and eel but many large gadids, even where sieving has been employed (e.g. Hamilton-Dyer et al. 2002). It is thought that the large gadids were primarily for trade, both internal and external, and indeed fish are known to have become an important Irish export during the Anglo-Norman period (McCormick 1991). The lack of herring and eel remains in Irish urban assemblages remains curious, however, as herring fishermen from Waterford are mentioned in at least one document (Kelly 1997, 297), and there was an established eel fishery on the Shannon by the thirteenth century (O’Neill 1987, 41). Indeed, by the sixteenth century herrings were amongst Ireland’s greatest export products (O’Neill 1987, 30–6). As such, it is clear that more assemblages of sieved material from Irish Medieval and Post-Medieval urban sites are needed to help elucidate the nature of the true situation.

Priorities for Future Research Analysis is of little use without dissemination of results; publication is therefore crucial to enable a wider discussion of the role of the bird and fish remains recovered from Irish archaeological excavations. There are a number of substantial collections that remain unpublished, some of which are mentioned in the current paper, and several where work is in progress. Doubtless there are others within the grey literature that have not come to the attention of the author. The assemblages discussed here are by no means exhaustive; the smallest collections have not been included and the results of assemblages retrieved from early excavations should be used with caution.

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Very few bird and fish bone reports have been produced for inland sites of the historic period, many of which are lacking sieved assemblages. Fish remains are particularly notable by their absence. Do these settlements follow the pattern apparent at Clonmacnoise, with some fish, probably of local origin, or do they have no fish at all? Do any have evidence of trade in marine fish? Some areas of Ireland, such as Munster, are poorly represented by faunal assemblages, especially for birds and fish (McCarthy 1998). Fish seem absent or rare from pre-Anglo-Norman sites from any area in Ireland, but it is difficult to interpret this as a genuine paucity without more, and sieved, assemblages. There is thus great potential in the accumulation of data from such sites, even if the individual samples are small. In some cases it has been possible to go beyond the species list level of reporting. Detection of processing and dumping areas; industrial, kitchen and plate waste; and even of butchery styles, has been reported with improved excavation strategies. Analysis in these subject areas is ripe for further research. Comparisons with material from other areas of north-west Europe are possible and desirable; the nearest neighbours Scotland and Wales are obvious candidates, but England and Scandinavia are also known to have had important links with Ireland. New research and application in the area of DNA and related techniques may help in the thorny question of separating the various goose and duck species and, together with metrical studies, track changes caused by domestication and husbandry techniques. Indeed, there is a general need to strengthen the database on sexing, ageing and metrical analysis of domestic birds. Similar work on fish should also be an important

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objective for future work. Detection of the trade in, and use of, stored fish in England has been explored by Locker (2001) and the same types of analyses could also be undertaken on Irish material. On an ecological front there is the possibility of logging the past distribution of bird species now absent in Ireland, or at least of restricted occurrence, and of detecting introductions. This type of work has already been explored by D’Arcy (1999) and Yalden and Carthy (2004). Similarly, the understanding of the historical distribution of freshwater fish in Ireland is still extremely patchy (McCormick 1999; Murray 1999) and would form a valuable topic for future research.

References Coy, J. and Hamilton-Dyer, S. 2005. ‘Flesh, Fish, Biscuit and Beer’: victuals for the Ship, pp. 602–12 in Gardiner, J. (ed.), Before the Mast: Life and Death Aboard the ‘Mary Rose’ (Archaeology of the Mary Rose Vol. 4). Oxford: Mary Rose Trust/Oxbow. D’Arcy, G. 1999. Ireland’s Lost Birds. Dublin: Four Courts Press. Davis, O. and Quinn, D. B. 1941. The Irish Pipe Roll of 14 John, 1211–1212. Ulster Journal of Archaeology 4 (supplement), 1–76. Down, K. 1987. Colonial society and economy in the High Middle Ages, pp. 439–91 in Cosgrove, A. (ed.), A New History of Ireland Vol. 2: Medieval Ireland 1169–1534. Oxford: Clarendon Press.

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FAO. 1997. Review of the State of World Fishery Resources: Marine Fisheries (FAO Fisheries Circular No. 920 FIRM/ C920). Rome: FAO Fisheries Department. Hamilton-Dyer, S. 1993. Bird and Fish Bones, Back Lane, Dublin. Unpublished report. Hamilton-Dyer, S. 1994a. Fish and Marine Invertebrates, Omey, Galway. Unpublished report. Hamilton-Dyer, S. 1994b. Bird, Fish and Marine Invertebrates, Staad Abbey, Co. Sligo. Unpublished report. Hamilton-Dyer, S. 1995. Fish in Tudor naval diet–with reference to the Mary Rose. Archaeofauna 4, 27–32. Hamilton-Dyer, S. 1996. Bird and Fish bones, Cornmarket and Bridge Street, Dublin. Unpublished report. Hamilton-Dyer, S. 1997a. Birds, fish and marine invertebrates from Site G, pp. 220–1 in Walsh, C., Archaeological Excavations at Patrick, Nicholas and Winetavern Streets, Dublin. Dingle: Brandon Books/Dublin Corporation. Hamilton-Dyer, S. 1997b. The Bird Bones from Trim Castle, Co. Meath. Unpublished report. Hamilton-Dyer, S. 1999a. Bird and Fish Bones from Dundrum Castle. Unpublished report. Hamilton-Dyer, S. 1999b. Bird and Fish Bones from Carrickfergus, Co. Antrim. Unpublished report. Hamilton-Dyer, S. 1999c. Fish Bones from Two Early Christian Sites at Doonloughan, Slyne Head, Co. Galway. Unpublished report.

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Hamilton-Dyer, S. 2000a. Fish and Bird Bones from Maynooth Castle, Co. Kildare. Unpublished report. Hamilton-Dyer, S. 2000b. The faunal remains, pp. 45–51 in Rawlings, M., Excavations at Ivy Street and Brown Street, Salisbury, 1994. The Wiltshire Archaeological and Natural History Magazine 93, 20–62. Hamilton-Dyer, S. 2002. Fish and fowl bones, pp. 192–3 in Comber, M., M. V. Duignan’s excavations at the ringfort of Rathgurreen, Co. Galway, 1948–9. Proceedings of the Royal Irish Academy 102C, 5–197. Hamilton-Dyer, S. 2004a. Fish and bird bones from Courthouse Lane, pp. 609–26 in Fitzpatrick, E., O’Brien, M. and Walsh, P. (eds.), Archaeological Investigations in Galway City, 1987–1998. Bray: Wordwell. Hamilton-Dyer S. 2004b. Fish bones, pp 235–8 in Hayden A., Excavation of the Medieval river frontage at Arran Quay, pp. 149–242 in Duffy, S. (ed.), Medieval Dublin V. Dublin: Four Courts Press. Hamilton-Dyer, S. 2005. Fish bone in White Marshall, J. and Walsh, C., Illaunloughan Island: An Early Medieval Monastery in Co. Kerry. Bray: Wordwell (specialist report available on CD from Wordwell). Hamilton-Dyer, S. in prep. Bird and Fish Bones from Clonmacnoise. Unpublished report. Hamilton-Dyer, S., Smith, C., Bullock, A. E. and Jones, A. K.G. 2002. The fish and bird bones, pp. 276–80 in Cameron, A. and Stones, J. (eds.), Aberdeen, An In-Depth View of the City’s Past (Society of Antiquaries of Scotland Monograph 19). Edinburgh: The Society of Antiquaries of Scotland. 280

Hutton Macdonald, R., Macdonald, K. C. and Ryan, K. 1993. Domestic geese from medieval Dublin, pp. 205–18 in Morales Muñiz A. and Rosello E. (eds.), Archaeornithology: birds and the archaeological record, proceedings of the first meeting of the ICAZ Bird Working Group, Madrid 1992. Archaeofauna 2. Jones, A. K. G. 1999. Walking the cod: an investigation into the relative robustness of cod, Gadus morhua, skeletal elements in Jones A. and Nicholson R. (eds.), Fishes and Humankind III (Internet Archaeology 7). http://intarch.ac.uk/ journal/issue7/jonestoc.html. Jope, M. 1954. Animal remains from Clough Castle, pp. 150–6 in Waterman D. M., Excavations at Clough Castle. Ulster Journal of Archaeology 17, 103–63. Kelly, F. 1997. Early Irish Farming (Early Irish Law Series 5). Dublin: Institute of Advanced Studies. Locker A. 2001. The Role of Stored Fish in England 900–1750 AD: The Evidence from Historical and Archaeological Data (Facsimile of University of Southampton Ph.D. thesis submitted in 2000). Sofia: PGL. Longfield, A. K. 1929. Anglo-Irish Trade in the Sixteenth Century. London: George Routledge and Sons Ltd. Maltby, J. M. 1997. Domestic fowl on Romano-British sites: inter-site comparisons of abundance. International Journal of Osteoarchaeology 7, 402–14. McCarthy, M. 1997. Faunal remains: Christ Church, pp. 349–59 in Cleary, R. M., Hurley, M. F. and Shee Twohig, E. (eds.), Skiddy’s Castle and Christ Church, Cork: Excavations 1974–77 by D. C. Twohig. Cork: Cork Corporation. 281

McCarthy, M. 1998. Archaeozoological Studies and Early Medieval Munster, pp. 59–64 in Monk, M. and Sheehan, J. (eds.), Early Medieval Munster: Archaeology, History and Society. Cork: Cork University Press. McCarthy, M. 1999. Faunal remains, pp. 85–92 in Woodman, P. C., Anderson, E. and Finley, N. (eds.), Excavations at Ferriter’s Cove: 1983–95. Bray: Wordwell. McCarthy, M. 2000. Hunting, fishing and fowling in late prehistoric Ireland: the scarcity of the bone record, pp. 107–17 in Desmond, A., Johnson, G., McCarthy, M., Sheehan, J. and Shee Twohig, E. (eds.), New Agendas in Irish Prehistory. Bray: Wordwell. McCarthy M. 2003. The faunal remains, pp. 375–89 in Cleary, R. M. and Hurley, M. F. (eds.), Cork City Excavations 1984–2000. Cork: Cork City Council. McCarthy M. n.d. A Report on the Faunal Remains from Viking and Medieval levels at Wexford. Unpublished report. McCormick, F. 1991. The effect of the Anglo-Norman settlement on Ireland’s wild and domesticated fauna, pp. 40–52 in Crabtree, P. J. and Ryan, K. (eds.), Animal Use and Culture Change (MASCA Research papers, Supplement to Vol. 8). Pennsylvania: University Museum. McCormick F. 1999. Early evidence for wild animals in Ireland, pp. 355–71 in Benecke, N. (ed.), The Holocene History of the European Vertebrate Fauna: Modern Aspects of Research (Archäologie in Eurasien 6). Rahden: Verlag Marie Leidorf GmbH. Monk, J. 1984. Appendix 3, The animal bones, pp. 37–54 in Cleary, R. M., Excavations at Lough Gur, Co. Limerick, 282

1977–1978: Part IV. Journal of the Cork Historical and Archaeological Society 89, 33–54. Murray, E. V. 1999. Early Evidence for Coastal Exploitation in Ireland. Unpublished Ph.D. thesis, Queen’s University Belfast. O’Neill, T. 1987. Merchants and Mariners in Medieval Ireland. Dublin: Irish Academic Press. O’Sullivan, T. 1990. The Exploitation of Birds in Viking Dublin (an avifaunal analysis of a bone sample from Fishamble St. 2). Unpublished MA thesis, National University of Ireland, Dublin. O’Sullivan, T. 2005. Bird bone in White Marshall, J. and Walsh, C., Illaunloughan Island: An Early Medieval Monastery in Co. Kerry. Bray: Wordwell (specialist report available on CD from Wordwell). Reichstein, H. and Pieper, H. 1986. Untersuchungen an skelettresten von Vögeln aus Haithabu (Ausgrabung 1966–1969). Neumünster: KWV. Reid-Henry, D. and Harrison, C. 1988. The History of the Birds of Britain. London: Collins. Roche, G. 1958. Animal bones, pp. 133–4 in O’Kelly, M. J., Church Island near Valencia, Co. Kerry. Proceedings of the Royal Irish Academy 59C, 57–136. Serjeantson, D. 1988. Archaeological and ethnographical evidence for seabird exploitation in Scotland. Archaeozoologia 2, 209–24. Stelfox, A. W. 1938. The birds of Lagore about one thousand years ago. The Irish Naturalists Journal 7, 37–43. 283

Stevens, K. F. and Olding, T. E. 1985. The Brokage Books of Southampton 1477–8 and 1527–8 (Southampton Records Series, Vol. 28). Southampton: Southampton University Press. Wheeler, A. 1978. Key to the Fishes of Northern Europe. London: Frederick Warne. Wheeler A. and Jones A. K. G. 1989. Fishes (Cambridge Manuals in Archaeology). Cambridge: Cambridge University Press. Wijngaarden-Bakker, L. H. van 1985. Littletonian Faunas, pp. 233–49 in Edwards, K. J. and Warren, W. P. (eds.), The Quaternary History of Ireland. London: Academic Press. Wijngaarden-Bakker, L. H. van 1986a. The animal remains from the Beaker settlement at Newgrange, Co. Meath: final report. Proceedings of the Royal Irish Academy 86C, 17–112. Wijngaarden-Bakker, L. H. van 1986b. The faunal remains, pp. 71–6 in Woodman P. C., Excavations at Mount Sandel 1973–77 (Northern Ireland Archaeological Monographs 2) Belfast: HMSO. Wijngaarden-Bakker, L. H. van 1989. Faunal Remains and the Irish Mesolithic, pp. 125–33 in Bonsall, C. (ed.), The Mesolithic in Europe. Edinburgh: John Donald. Wilkinson, M. 1979. The fish remains, pp. 74–81 in Maltby, J. M., Faunal Studies on Urban Sites: The Animal Bones from Exeter 1971–1975 (Exeter Archaeological Reports 2). Sheffield: University of Sheffield.

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Yalden, D. W and Carthy, R. I. 2004. The archaeological record of birds in Britain and Ireland. Environmental Archaeology 9, 123–6.

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Acknowledgements Many thanks to Tanya O’ Sullivan and Emily Murray for permission to use unpublished data.

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7 Molluscs and Middens: The Archaeology of ‘Ireland’s Early Savage Race’? Emily V. Murray

Abstract Shellfish have been eaten, and their shells discarded, around the Irish coastline from the earliest occupation of the island through to the present day. The physical, social and economic contexts in which these exploitations were undertaken seems to have varied between time and place. Archaeological excavations, surveys and radiocarbon dating, along with the application of new scientific techniques and approaches, have gone some way in providing a chronological and geographical overview of the role of molluscs and middens in Ireland.

Introduction Marine molluscs have been found on numerous archaeological sites in Ireland. The primary type-site on which they occur, and with which they are most commonly associated, are shell middens. Although shell middens are well known archaeological field sites in Ireland and abroad, they vary widely in size, composition and date and may occur in apparent isolation (Figs. 7.1 and 7.2), or in association with

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other aspects of settlement, as at the island monastery of Illaunloughan, Co. Kerry, for example (White Marshall and Walsh 2005). One useful, albeit broad, definition of a shell midden is of ‘a cultural deposit of which the principle visible constituent is shell’ (Waselkov 1987, 95). The potential of shells to inform on past economies and environments is wide ranging and shells originating in freshwater and terrestrial, as well as marine environments, have all been found on Irish sites. Unfortunately, the former two types are not commonly recovered nor recorded so we cannot make a true evaluation of their occurrence. In contrast, marine molluscs are well represented. In most cases reports on shellfish assemblages comprise a list of identified species and their relative frequency. These basic records indicate the range of species eaten and can suggest whether there were deliberate harvesting tactics in which particular species were targeted. Despite the conspicuous presence of such shells in middens and on other sites where present, ethnographic accounts from around the world emphasise that where shellfish are consumed this is principally as a dietary supplement benefiting it with respect to vitamins and minerals as opposed to calories (Waselkov 1987, 142, 166). This is further confirmed if one converts the shellfish to calorific values. The real possibilities of archaeological deposits of shells do not therefore lie in the reconstruction of diet but rather in the potential insight that they can give into wider aspects of a site’s function, culture, economy and environment.

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Figure 7.1: Map showing the location of the sites mentioned in the text. Lists of shells from archaeological contexts provide an indication of the nature and type of shorelines exploited. The presence of shellfish which are not now found in the present-day local fauna can, for example, inform on a change in the physical nature of the adjacent coastline or of the species’ previous distribution. This is particularly relevant for 289

the raised beaches of the Atlantic period (i.e. the Holocene climatic optimum, c. 8000–5000 BP) in which the presence of ‘typical warm forms’ have been found, such as Venus verrucosa at Rosapenna, Co. Donegal (Praeger 1896–8, 50). The size and shape of shells and the nature of infesting and encrusting organisms can also indicate their provenance within the intertidal zone or the type of substrate in the case of deep-water species. This data can potentially inform on the management of shellfish which has proven particularly successful for large assemblages of oysters from a number of English sites, including the Roman port of London and the Saxon town of Hamwih (Winder 1980; 1985). Metrical analysis may also indicate the degree of exposure of the foreshore from which particular shellfish were harvested and the ‘squatness’ of dogwhelks, for example, has been shown to reflect the degree of storminess of their environment (Andrews et al. 1987; Brown et al. 1998). The breakage patterns or modification of shells can show how they were processed and what they were used for, such as food (Fig. 7.3), bait, dye (Fig. 7.4) or ornamentation, while the presence of incidental species can provide indirect evidence for the introduction of seaweed or driftwood (Fig. 7.5) onto a site. At a microscopic level, the determination of the season of harvest is potentially possible through the analysis of tidal and annual growth lines (Deith 1983; Milner 2001) or the oxygen isotope ratio (Shackleton 1973) in certain shells’ physical and chemical structures.

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Figure 7.2: Eroding shell midden, Omey Island, Co. Galway. Despite the tendency to assume that middens are a product of a Mesolithic (i.e. hunter-gatherer) society excavations have demonstrated that shellfish consumption in Ireland dates from Mesolithic settlement through to the Post-Medieval period; indeed the majority of dated shell middens actually post-date the Mesolithic period (Woodman and Milner 2001, 33). Unlike ringforts or megaliths, for example, identifying the occupants of isolated middens by placing them within their broader cultural landscape through spatial and statistical analysis is not easily done as the composition and semblance of such sites are not temporally diagnostic. Middens feature prominently in the antiquarian reports of the nineteenth and early twentieth centuries and ‘a sea-shore habitat of some early savage race’ was how one such investigator, Bertram Windle (1911, 1), interpreted a midden that he happened upon at Kinnegar Bay on the shores of Lough Swilly, Co. Donegal. Such a conclusion was not atypical, as absolute techniques required to decipher the antiquities discovered then were 291

lacking, and also because these ‘settlements’ were minimalist and did not have much, if any, structural remains. Conventional wisdom also held that the former ‘occupants’ and producers of the middens relied on shellfish for the greater part of their sustenance and thus the rationale that these must be the remains of poor, primitive ‘strandloopers’ (Brunicardi 1914, 208; MacAlistair 1921, 73–4). Nearly a century on and an integration of Irish shell middens into their cultural and economic context has arguably only marginally progressed. The application of new scientific techniques including isotopic analysis on human bone to determine diet, microscopic analysis of shells to identify seasonality and the increased application of radiocarbon dating is, however, slowly revealing the role of shellfish at different times in the past.

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Figure 7.3: Nicked oyster valves from Rathgurreen ringfort, Co. Galway.

Figure 7.4: Broken dogwhelk shells (Nucella lapillus) from Doonloughan, Co. Galway.

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Figure 7.5: Goose barnacle plates (Lepas anatifera) from an Early Christian sandhill site at Doonloughan, Co. Galway.

Mesolithic (c. 7000–4000 BC) The Mesolithic economy was a hunter-gatherer one and evidence for settlement from the period has a coastal, riverine and lakeside distribution (Woodman 1978). Movement between these areas would have ensured a year-round supply of food, with a heavy reliance on sea fish as few freshwater fish were available. If red deer were also not present in Ireland during this time, as seems likely given its absence on Mesolithic sites (Woodman et al. 1997, 130, 152), then the reliance on alternative sources such as wild pig, sea mammals, sea fish and shellfish would have been more acute than elsewhere in Europe. Much of the Mesolithic shoreline where shell middens would have existed has been buried beneath later post-glacial deposits due to changes in land and sea levels although some contemporary lithic scatters have been found along the coast at locations such as at Portrush, Grangemore and Portballintrae, Co. Antrim (Woodman 1978, 277–81). Many Late Mesolithic sites were specialised in flint-working especially those along the north and north-eastern coast where flint resources are readily available. Unfortunately, such sites generally produce little organic material so it is not possible to ascertain the nature of their food economy and it would seem that the acquirement of industrial raw materials was the primary factor for their existence. In apparent contrast, is a relatively large oyster midden on Rough Island in Strangford Lough which was excavated as part of the Harvard expedition in the 1930s and dated to the Late Mesolithic (Movius 1940). 294

Recent reinvestigations of the site, however, produced Western Neolithic pottery and charred wheat grains and although some Late Mesolithic flints were found these came from derived contexts (O’Neill et al. 2001). Artefactual evidence suggests that the date of the midden should be after c. 4000 BC and not Late Mesolithic as Movius had proposed (O’Neill et al. 2001, 50), but this will have to await the outcome of radiocarbon analysis which has not yet been undertaken (J. Mallory 2006, pers. comm.). There is, however, some potential for economic reconstruction in the case of the Late Mesolithic coastal sites of Counties Dublin and Louth where sites rich in organic material are located along the raised beaches of the area. At Rockmarshall, Co. Louth (Mitchell 1945–8; 1949–52), excavations of middens produced flints from the Late Mesolithic and a wide range of shellfish species, fully listed in the reports, but comprising mainly oysters, periwinkles and carpet shells (Tapes decussatus). The excavator also noted that crab claws and fish bones were ‘rather common’, while the ‘scraps of bone’ that were found included seal. No constructional hearths were present, only hollows in the ground suggesting temporary habitation. A recent assessment of the incremental growth structure of the oysters from the site indicated that they were gathered from March through to August (Woodman and Milner 2001, 34). South of Rockmarshall another two Mesolithic shell middens were investigated–at Sutton at the north end of Dublin Bay (Mitchell 1956; 1972; Liversage 1968, 174–5) and Dalkey Island (Liversage 1968) at the south end of the bay. The former was a relatively large midden and produced a range of shellfish and bones of fish, bird, dog and pig, and possibly also hare and red deer, while at Dalkey the shellfish

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assemblage was dominated by limpets and periwinkles and bones of bird, fish, seal, dolphin and other wild animals were identified. The assemblage also yielded a number of bones of domestic animals indicating that there was a problem of contamination at this site. This has been confirmed by the Quaternary Faunas Dating Project which produced a wide range of dates for the Dalkey middens suggesting that they originated from disparate events in both the Mesolithic and the Late Neolithic or Early Bronze Age (Woodman et al. 1997, 137–8). This suggestion of multiple occupations has also been noted at other Late Mesolithic sites. Excavations of middens at Ferriter’s Cove on the Dingle peninsula between 1983 and 1995 uncovered firespots, hearths, chipping floors, postholes, stakeholes and shell dumps, all remnants of the principal activities of shellfish gathering, fishing and flint knapping (Woodman et al. 1999). The shell dumps were divided into two categories; larger deposits that probably served as dumps following processing and smaller dumps which may represent direct food dumps and which showed a greater diversity of artefacts and faunal remains and had a tendency to be associated with firespots. Radiocarbon dating showed that the main period of occupation centred on 4500 cal. BC, with a later event having occurred between 4500–4000 cal. BC. It was with this latter occupation that cattle bones were associated, the occurrence of which implies a continued use of the sea during the early stages of Neolithic farming (Woodman et al. 1999, 138). The overall interpretation of the site is that it was a Late Mesolithic temporary camp which was visited in late summer-autumn (based on the analysis of fish and bird remains) to exploit organic and lithic resources of the immediate locality.

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Two additional sites that can be added to this series of Late Mesolithic middens are Baylet on Inch Island in Lough Swilly, excavated by Peter Woodman and Nicky Milner, and Kilnatierny near Greyabbey, Co. Down (Fig. 7.1; Murray 2004). Both are dominated by oyster shells and a series of dates on pig bones and charred hazelnut shells from Baylet have returned dates that range between the mid fifth to mid sixth millennia cal. BC (N. Milner 2006, pers. comm.). Radiocarbon dates on bone from Kilnatierny have been returned with values of 5365±36 (UB-6835) and 5546±36 (UB-6836) which calibrate at 2-sigma to 4329–4055 cal. BC and 4452–4341 cal. BC respectively. Shellfish dominated the site matrix at Kilnatierny (oysters, scallops, periwinkles and limpets) but a small number of undiagnostic worked flints, poorly preserved pig teeth and a casual hearth or firespot were also uncovered. At both Ferriter’s Cove and Rockmarshall some human bone was also found and the results of stable isotope analysis of the bone collagen gave δ13C measurements of -14‰ and -18.1‰ respectively (Woodman et al. 1997, 143). These indicate that the individuals in question did not rely exclusively on a marine diet but that it must have formed a significant component, especially in the case of the Ferriter’s Cove specimen. These results correspond with measurements of human bone from contemporary sites elsewhere in Europe, which also indicate a marine diet, probably made up predominantly of fish (Richards and Hedges 1999).

Neolithic (c. 4000–2500 BC) Certain Neolithic coastal activity is indicated by the presence of pottery and worked flint objects in sandhills around Ireland including at Dundrum, Co. Down (Knowles 1889–91, 179;

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Collins 1952; 1959), and Portstewart, Co. Londonderry (McLMay and Batty 1948, 131). There is, however, a problem of chronology at these particular sites due to wind erosion and conflation and repeated use of the areas throughout the historic and prehistoric periods. Indeed, conflation was an issue that troubled and caused much debate among the antiquaries (Knowles 1889–91, 621; Hassé 1890–1; Hewson 1936, 155–7); although Neolithic artefacts have been discovered in proximity to organic materials such as animal bone, shellfish and dark organic-rich layers, a lack of dating and excavation does not allow demonstration of contemporaneity. This makes it difficult to determine the function and role of the shoreline for the people who obviously visited it during this period. Shell middens of a very different nature are to be found along the north shores of Ballysadare Bay, Co. Sligo (D’Evelyn 1904, 216–7; Österholm and Österholm 1984). In 1980 and 1981 a series of excavations were carried out on these middens which were dominated by oysters, although other shellfish present included cockles, mussels, periwinkles, and more sporadically, limpets, scallops and common whelks. Animal bones, chert waste and pottery remains were retrieved and radiocarbon samples dated the main activity to the Late Neolithic and Bronze Age (Burrenhult 1984, 131–2). The middens therefore post-date the main time-span of the adjacent megalithic cemetery of Carrowmore, although Burrenhult (1984, 133) has argued that middens used in earlier periods may have been lost through marine erosion. The size of the oysters increased the deeper (i.e. the earlier) the shell midden was excavated and this diminution in size over time suggested that the local stock had been over-exploited (Österholm and Österholm 1984, 322). It was

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also speculated that the oysters were gathered in winter based on the growth-line analysis of some of the shells coupled with the presence of huge hearths at the site (Österholm and Österholm 1984, 322). The dates from Rough Island, Co. Down, are still awaited but the limited artefactual evidence suggests that it is probably Neolithic. Early Neolithic dates were also returned for one of the oyster middens investigated at Baylet (N. Milner 2006, pers. comm.). These sites, together with the middens at Cullenamore, Co. Sligo, indicate that oysters were eaten in vast quantities during the Neolithic at least in certain parts of the country. This seems to contradict the results from stable isotope analysis of human bone from contemporary European sites which suggests that after the Mesolithic a marine component in the diet was negligible (Schulting 1998). It is highly unlikely, however, that ‘Neolithicisation’ was a reversible process and it is probable the shell middens can be interpreted in the context of a Neolithic culture (and indeed all subsequent cultures) reverting to at least some aspects of a hunter-gatherer economy on occasion. Coastal resources may have been exploited in times of stress or when people undertook specialised activities or festive seasonal gatherings on, or close to, the shore. The evidence from Ferriter’s Cove supports this view as do the materials dating to around the fourth millennium BC discovered near Carrigdirty Rock in the Shannon estuary (O’Sullivan 1997, 15). If this was the case, then such apparently intensive but sporadic binges on marine foodstuffs may not have been significant enough to alter the isotopic signature in human bone. Seashells have also been found on ritual sites from the Neolithic period. At the megalithic cemetery of Carrowmore,

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Co. Sligo, unopened burnt seashells, mussels and oysters were found in one of the tombs (Tomb No. 7) and have been interpreted as offerings (Waddell 1998, 71). Perforated seashells, as well as scallop and oyster shells, were found at Fourknocks, Co. Meath (McCormick 1985–6, 39). Seashells have also been found in other Neolithic megaliths; those of the Linkardstown tradition and other passage tombs, including Poulawack, Co. Clare, and Moylehid, Co. Fermanagh. Due to the lack of recording, however, it is unclear whether the deposits are primary or secondary in nature, and the apparent discovery of boar tusks with the shells at the latter two sites is more suggestive of Bronze Age activity (McCormick 1985–6, 39).

Bronze Age (c. 2500–600 BC) The archaeology of the Early Bronze Age comprises extensive burial evidence in the form of wedge tombs, barrows and cists and marine shells have been found deposited with various contemporary burials, both cremations and inhumations (McCormick 1985–6, 45). As has been mentioned above, the material recorded from certain Neolithic megaliths, including seashells, was often found in disturbed contexts suggesting later activity at these sites, including possible Bronze Age activity. The domestic evidence for the Early and Middle Bronze Age periods, is more limited and tends to be in the form of scattered sherds or pits, although Bronze Age pottery appears to comprise a sizeable proportion of the sherds found on sandhill sites (Knowles 1893–6, 660–1). The pottery recovered from Portstewart, Co. Londonderry, and quantified by McLMay and Batty (1948, 145), indicated a predominance of Bronze Age rather that Neolithic pottery. Knowles

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describes his illustrations of the typical pottery of the sandhills as, ‘in nowise [sic.] differs from the ordinary sepulchral vessels which belong principally to the Bronze Age’ (Knowles 1893–6, 660–1). Slag and crucibles have also been found alongside organic deposits in the sandhills which points to activity dating to the Bronze Age or later (Patterson 1894; Evans 1941; McLMay and Batty 1948). A coastal Food Vessel midden excavated at False Bay near Ballyconneely, Co. Galway, produced pottery, charcoal, charred grain, shellfish (predominantly limpets and periwinkles), and a small number of bones which included red deer and otter but no fish bone (Murray 1996). Isotopic analysis of the residues on the interior of the Food Vessel pot recovered from the primary excavations in 1992 (McCormick et al. 1996) also indicated that cereals, and not marine-derived material, had been cooked in the pot. There was no evidence for a substantial structure of any sort at the site and, as with the earlier temporary encampment recorded at Ferriter’s Cove in Co. Kerry, the False Bay site also had shells placed in discrete heaps adjacent to firespots suggesting the remains had originated from individual meals (Fig. 7.6). Other Bronze Age shell middens have been recorded at Magheragallen, Co. Donegal (Evans 1941); Dundrum, Co. Down (Collins 1952); Dalkey, Co. Dublin (Liversage 1968); Beginish, Co. Kerry (O’Sullivan and Sheehan 1996, 18); Omey Island, Co. Galway (O’Keefe 1993), Cregg, Co. Sligo (P. Woodman 2006, pers. comm.) and at Poul Gorm, Glengarriff, Co. Cork (McCarthy 1987). It is difficult to make a statement about the consumption of shellfish and coastal exploitation in general during the centuries spanning the Bronze Age. The evidence from the

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Late Bronze Age, such as that from Dún Aonghasa on Inis Mor (Cotter 1996), simply suggests that coastal resources were available so they were used but that ulterior motives were behind the choice of site. It is far from clear, however, what the nature of settlement was during the Early Bronze Age although the excavations at False Bay, Co. Galway, suggest at least some transient exploitation and settlement along the coast (McCormick et al. 1996; Murray 1996).

Figure 7.6: Informal hearth, shell dump (predominantly periwinkles) and large stone (used as a seat?) uncovered during the excavation of an Early Bronze Age midden at False Bay near Ballyconneely, Co. Galway.

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Iron Age (c. 600 BC–400 AD) The archaeological and environmental evidence for the Iron Age both indicate that the weather became much wetter (Raftery 1994, 115) and ceremonial sites, such as Emain Macha, Co. Armagh, Dún Ailinne, Co. Kildare, and the Dorsey earthwork, were built during this period. This disposition towards ritualism is also in evidence in coastal resource exploitation. The deliberate deposits of marine shells in Altar wedge tomb, Co. Cork, were found in Iron Age or Medieval contexts (O’Brien 1999, 129) and the absence of shells at the nearby Toormore tomb was interpreted as indicating an absence of Iron Age activity at the site (O’Brien 1999, 129). The relative scarcity of archaeological material from the period extends to the evidence for coastal settlement, although some sites have been recorded. At Ballymulholland on Magilligan Foreland, Co. Londonderry, three eroding shell middens, radiocarbon dated to the Iron Age and Medieval periods, were excavated in 1984 (Mallory and McCormick 1988). The middens contained deposits of charcoal, shell, bone and some metal slag. The bones represented the main domestic animals, while wild species included red deer, cetacean, gannet and common gull and the shellfish assemblage was unusually dominated by clams or quahogs (Arctica islandica). The middens at Cullenamore, Co. Sligo, included Early Iron Age horizons (Burrenhult 1984, 132), and Early Iron Age shell middens have also been recorded along the southern shores of Mannin Bay, Co. Galway (McCormick et al. 1996). The discovery and record of these sites at Mannin is extremely important as not only have they now disappeared through coastal erosion, but little if any other

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evidence for occupation in the region during this time period has been identified.

Early Christian (400–twelfth century AD) The introduction of documentary sources in the Early Christian period provides little additional information on the use of shellfish in Ireland as there are hardly any acknowledgements of marine resource exploitation (Kelly 1997). This neglect in the literature can perhaps partly be explained by the apparent low status of shellfish as food, while a law text written specifically dealing with maritime matters, the Muirbreatha or ‘sea-judgements’, is lost (Kelly 1997, 285, 296). Its known existence and the certainty that it would have contained particulars on coastal resources and their exploitation, indicate that the resources of the sea and shoreline were valued and utilised during this period. This is corroborated by extensive archaeological remains found on a wide range of monastic and secular sites, the majority of which survive along the west coast (Table 7.1). In addition to the usual limpets, periwinkles and other food species, as shown by Table 7.1, excavations of two Early Christian sandhill sites at Doonloughan, Co. Galway (Murray 1999), adjacent to the Early Bronze Age midden at False Bay, also produced pallets of shipworms (Teredo sp.) and plates of the goose barnacle (Lepas anatifera). Although the respective pallets and plates of these two animals look like ‘shells’ (see Fig. 7.5), both species are in fact crustaceans. The two species live exclusively on, or within, waterlogged wood in seawater and as the specimens derived from deposits dense with charcoal, it would suggest that driftwood had been collected and burnt. Mitchell (1949–52, 16) noted the presence of shipworms as represented by their tube linings at the

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Mesolithic middens at Rockmarshall, and he also suggested that they could have made their way to the site ‘embedded in driftwood’. Large numbers of blue rayed limpets (Helicon laevis) and flat winkles (Littorina obtusata), both small shellfish that live on seaweeds, were also found in the sieved samples from Doonloughan. Their presence indicates that quantities of seaweed must have been introduced to the site, and comparable molluscan assemblages from English and Scottish sites have been similarly interpreted (Bell 1981, 122; Murphy and Rackham 1995, 217; Russell et al. 1995, 285). At Dún Eoghanachta, Co. Galway, and Illaunloughan, Co. Kerry, huge quantities of fish bones were found (see Hamilton-Dyer, this volume) and it is probable that some of the shellfish found at both sites were used as bait, as was common practice on the Arran Islands in more recent times (Robinson 1990, 36, 85; O’Flaherty 1991, 33). Doonloughan, and several other west coast Early Christian sites including Dog’s Bay, Co. Galway (Bigger 1895), Inishkea North, Co. Mayo (Henry 1952) and Dooey, Co. Donegal (O’Riordain and Rynne 1961; see Table 7.1 for full list of sites), also produced piles of broken dogwhelks (Nucella lapillus). The nature of the shells’ fractures would suggest that they were broken to gain access to the fishes’ hypobranchial gland (see Fig. 7.4). The secretion in this gland may have been used as a dye as it photo-oxidises to a fast purple colorant. The properties and commercial exploitation of the dye from its larger and better known relative the Murex of the Mediterranean, has been well documented and the Murex dye was famously described by both Pliny and Aristotle (see Cooksey 1994 for an extensive bibliography). The evidence for the possible procurement of this dye from Irish dogwhelks

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is discussed in greater detail elsewhere (Bigger 1895; Henry 1952; Murray 1999).

Table 7.1: Shellfish spiecies recorded in Early Christian sites in Ireland (after Murray 1999). Although the majority of

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material was recovered specifically from a midden, where the site context is also known this is the ’site type’ assigned, e.g. moanstery, fingfort etc. Key: cr= crannog, cv= cave, enc= enclosure, bs= but site, md=midden, mn=monastery, pf=promontory fort, rf= ringfort, st=souterrain, ur= urban, x= present, -= absent, xx= broken dogwhelks, * identified as ’banacle shells’.

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Where shellfish are found on inland sites, the species represented are invariably bivalves as the majority of bivalves clamp their valves shut when removed from the water thereby keeping them moist and fresh and suitable for transportation. For example, oysters were found at the high status inland site

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of Lagore Crannog, Co. Meath (McCormick 1987), and at the ringfort of Ardcloon, Co. Mayo (Rynne 1956, 213), while a wider range of bivalves were found at Cahercommaun, Co. Clare (Hencken 1938). Marine molluscs have also been found in contemporary urban contexts in the Viking towns of Dublin and Waterford, but much of the material has either not been studied or published. It is therefore not possible at present to evaluate the role of coastal resource exploitation in the urban Scandinavian economy in Ireland. In urban deposits of the twelfth and thirteenth centuries and later, shellfish, predominantly oysters, are commonly found. This correlates with the preliminary results of stable isotope analysis of human bone from the Medieval period in Ireland which suggests that a marine component again assumes a more significant role in the diet at this time, not recorded since Mesolithic times (Woodman 2004, fig. 4.7). The results are, however, based on a small number of skeletal samples spread unevenly across the prehistoric and historic periods and further analyses needs to be done to confirm this trend.

Conclusion Ongoing erosion of the coastline exposes new shell middens (Fig. 7.2) which, once revealed, are susceptible to deterioration and loss. Other developments have also hugely modified the coastal landscape, in particular the expansion of golf courses and the increased interest in surfing (Siggins 2005), while the middens themselves have been plundered as a resource for lime-making and manure (Hutton 1892, 168; Knowles 1893–6, 652; Coleman 1938, 44; Raftery 1944, 37–90). The transformation of the coast due to these and other factors and the value of fieldwalking in monitoring and

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recording new and disappearing sites have long been recognised. This has most recently been demonstrated by the extensive survey of the intertidal archaeology of Strangford Lough (McErlean et al. 2002) and on a smaller scale on the Inishkea Islands of Co. Mayo (Gibbons 2004). Although the record of middens for Strangford Lough is biased towards certain areas which were specifically targeted, the gazetteer of sites compiled shows that the number of known sites has dramatically increased (McErlean et al. 2002, 190). Surveys of middens on a smaller scale, such as in the Doonloughan area of Co. Galway (Murray 1999), have had similar results in increasing the number of known sites. The problem of stray, eroded-out finds is particularly acute along the coastal zone with eclectic lists of finds published by antiquarians comprising pottery, pins, tokens, beads, flints, hammer-stones, axes and ‘rude stone flakes’ along with faunal remains. The lists of middens in county archaeological inventories are also valuable records but they too are of limited archaeological interest without a cultural context. These inventories need to be reconsidered and revisited along with a review of the stray finds and antiquarian accounts which together could potentially highlight key areas for further investigation and excavation. The excavation of these and other shell middens could also provide well-stratified material of both marine and terrestrial origin, the analysis of which could make a valuable contribution towards the accuracy of radiocarbon calibration of marine-derived materials (Reimer et al. 2002). Lastly, in conjunction with surveys, excavations and scientific applications, social and ethnographic factors need to be considered in more detail as these may have determined the

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scheduling of movement towards the coast. The harvesting of shellfish in winter–only months that have an ‘r’ in their name–is a practice still largely observed in Ireland, while ethnographic evidence from around the world demonstrates that the gathering of shellfish is done almost entirely by women and children (Bonsall 1997, 32). Attitudes and perceptions of shellfish as food also change over time and this is best demonstrated by the oyster, once a food of the poor during the nineteenth century famines, now a food of the affluent (Woodman and Milner 2001, 33). These are not issues that we can easily test for the prehistoric and Early Christian periods in Ireland but they are potential subjects that need to be considered.

References Andrews, M. V., Gilbertson, D. D. and Kent, M. 1987. Storm frequencies along the Mesolithic coastline, pp. 108–14 in Mellars, P. (ed.), Excavations on Oransay. Edinburgh: Edinburgh University Press. Bell, M. 1981. Seaweed as a prehistoric resource, pp. 117–26 in Brothwell, D. and Dimbleby, G. (eds.), Environmental Aspects of Coasts and Islands: Symposia for the Association for Environmental Archaeology No. 1 (BAR International Series 94). Oxford: British Archaeological Reports. Bigger, F. J. 1895. Prehistoric settlement at Portnafeadog in the parish of Moyrus, Connemara. Proceedings of the Royal Irish Academy 3, 727–32. Bonsall, C. 1997. Coastal adaptation in the Mesolithic in Argyll. Rethinking the ‘Obanian problem’, pp. 25–37 in Ritchie, G. (ed.), The Archaeology of Argyll. Edinburgh: Edinburgh University Press.

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Brown, T., Crane, S., O’Sullivan, D., Walsh, K. and Young, R. 1998. Marginality, multiple estates and environmental change: the case of Lindisfarne, pp. 139–48 in Mills, C. M. and Coles, G. (eds.), Life on the Edge: Human Settlement and Marginality (Oxbow Monographs 100). Oxford: Oxbow Books. Brunicardi, M. 1914. The shore-dwellers of ancient Ireland. Journal of the Royal Society of Antiquaries of Ireland 44, 185–213. Burrenhult, G. 1984. The Archaeology of Carrowmore: Environmental Archaeology and the Megalithic Tradition at Carrowmore Co. Sligo, Ireland (Theses and Papers in North-European Archaeology 14). Stockholm: University of Stockholm. Coleman, J. C. 1938. The kitchen middens of Cork harbour. Journal of the Cork Historical and Archaeological Society 43, 39–44. Collins, A. E. P. 1952. Excavations in the sandhills at Dundrum, Co. Down. Ulster Journal of Archaeology 15, 2–26. Collins, A. E. P. 1959. Further Investigations in the Dundrum sandhills. Ulster Journal of Archaeology 22, 5–20. Comber, M. 2002. M. V. Duignan’s excavations at the ringfort of Rathgurreen, Co. Galway, 1948–9. Proceedings of the Royal Irish Academy 102C, 137–97. Cooksey, C. 1994. Bibliography of Tyrian purple. Dyes in History and Archaeology 12, 57–66.

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Cotter, C. 1996. Dún Eoghanachta, pp. 32–3 in Bennett, I. (ed.), Excavations 1995, Summary Accounts of Archaeological Excavations in Ireland. Bray: Wordwell. Deith, M. R. 1983. Molluscan calendars: the use of growth-line analysis to establish seasonality of shellfish collection at the Mesolithic site of Morton, Fife. Journal of Archaeological Science 10, 423–40. D’Evelyn, A. M. 1904. Prehistoric archaeology. The Irish Naturalist 13, 216–20. Evans, E. E. 1941. A sandhill site in Co. Donegal. Ulster Journal of Archaeology 4, 71–5. Gibbons, M. 2004. Inishkea island discovery. Archaeology Ireland 18 (3), 5. Hassé, L. 1890–1. Objects from the sandhills at Portstewart and Grangemore, and their antiquity. Journal of the Royal Society of Antiquaries of Ireland 21, 130–8. Hencken, H.O’N. 1938. Cahercommaun: a stone fort in County Clare (Extra volume of the Journal of the Royal Society of Antiquaries of Ireland). Dublin: The Royal Society of Antiquaries of Ireland. Henry, F. 1952. A wooden hut on Inishkea North, Co. Mayo. Journal of the Royal Society of Antiquaries of Ireland 82, 163–78. Hewson, L. M. 1936. Notes on Irish sandhills. Journal of the Royal Society of Antiquaries of Ireland 66, 154–71. Hutton, A. W. (ed.). 1892. Arthur Young’s Tour in Ireland 1776–1779 (Vol. 1). London: George Bell and Sons.

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Kelly, F. 1997. Early Irish Farming (Early Irish Law Series 5). Dublin: Institute of Advanced Studies. Knowles, W. J. 1889–91. Report on the prehistoric remains from the sandhills of the coast of Ireland. Proceedings of the Royal Irish Academy 1, 173–87. Knowles, W. J. 1893–6. The third report on the prehistoric remains from the sandhills of the coast of Ireland. Proceedings of the Royal Irish Academy 3, 650–63. Liversage, G. D. 1968. Excavations at Dalkey Island, Co. Dublin 1956–9. Proceedings of the Royal Irish Academy 66C, 53–233. MacAlistair, R. A. S. 1921. Ireland in Pre-Celtic Times. Dublin: Maunsel and Roberts Ltd. Mallory, J. P. and McCormick, F. 1988. Excavations at Ballymulholland, Magilligan Foreland, Co. Londonderry. Ulster Journal of Archaeology 51, 103–14. Mallory, J. P. and Woodman, P. C. 1984. Oughtymore; an Early Christian shell midden. Ulster Journal of Archaeology 47, 51–62. McCarthy, A. 1987. Poul Gorm, Glengarriff, p. 15 in Bennett, I. (ed.), Excavations 1986, Summary Accounts of Archaeological Excavations in Ireland. Bray: Wordwell. McCormick, F. 1985–6. Faunal remains from prehistoric Irish burials. Journal of Irish Archaeology 3, 37–48. McCormick, F. 1987. Stockrearing in Early Christian Ireland. Unpublished Ph.D. thesis, Queen’s University Belfast.

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McCormick, F., Gibbons, M., McCormac, F. G. and Moore, J. 1996. Bronze Age to medieval coastal shell middens near Ballyconneely. Journal of Irish Archaeology 7, 77–84. McErlean, T., McConkey, R. and Forsythe, W. 2002. Strangford Lough. An Archaeological Survey of the Marine Cultural Landscape. Belfast: Blackstaff Press. McLMay, A. and Batty, J. 1948. The sandhill cultures of the river Bann estuary, Co. Londonderry. Journal of the Royal Society of Antiquaries of Ireland 78, 130–56. Milner, N. 2001. At the cutting edge: using thin sectioning to determine season of death of the European Oyster, Ostrea edulis. Journal of Archaeological Science 28, 861–73. Mitchell, F. 1945–8. An early kitchen midden in County Louth. County Louth Archaeological Journal 2, 169–74. Mitchell, F. 1949–52. Further early kitchen middens in County Louth. County Louth Archaeological Journal 12, 14–20. Mitchell, F. 1956. An early kitchen midden at Sutton, Co. Dublin. Journal of the Royal Society of Antiquaries of Ireland 86, 1–26. Mitchell, F. 1972. Further excavations of the early kitchen middens at Sutton Co. Dublin. Journal of the Royal Society of Antiquaries of Ireland 102, 151–9. Movius, H. L. 1940. Report on a stone age excavation at Rough Island, Strangford Lough, County Down. Journal of the Royal Society of Antiquaries of Ireland 70, 111–42. Murphy, M. and Rackham, D. J. 1995. Marine molluscs, pp. 216–20 in Morris, C. D., Batey, C. E. and Rackham, D. J. 315

(eds.), Freswick Links, Caithness: Excavations and Survey of a Norse Settlement. Inverness: Highland Libraries. Murray, E. V. 1996. An Early Bronze Age Settlement Site at False Bay, Connemara. Unpublished B.Sc. thesis, Queen’s University Belfast. Murray, E. V. 1999. Early Evidence for Coastal Exploitation in Ireland. Unpublished Ph.D. thesis, Queen’s University Belfast. Murray, E. V. 2004. Kilnatierny, Greyabbey, Co. Down (KLT04). Unpublished Queen’s University Belfast and Environment and Heritage Service DOE: NI Data Structure Report No. 30. O’Brien, W. F. 1999. Sacred Ground: Megalithic Tombs in Coastal South- West Ireland (Bronze Age Studies 4). Galway: NUIG. O’Flaherty, T. 1991. Aranmen All. Dingle: Brandon Book Publishers Ltd. O’Keefe, T. 1993. Omey Island–Gooreen and Sturrakeen, pp. 30–1 in Bennett, I. (ed.), Excavations 1992, Summary Accounts of Archaeological Excavations in Ireland. Bray: Wordwell. O’Neill, L., Donnelly, C., Mallory, J. and McNeill, T. 2001. Rough Island Research Excavation: Data Structure Report 2001. Unpublished Queen’s University Belfast and Environment and Heritage Service DOE: NI Data Structure Report.

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O’Riordain, A. B. and Rynne, E. 1961. A settlement in the sandhills at Dooey, Co. Donegal. Journal of the Royal Society of Antiquaries of Ireland 91, 58–64. O’Sullivan, A. 1997. Last foragers or first farmers? Archaeology Ireland 11, 14–6. O’Sullivan, A. and Sheehan, J. 1996. The Iveragh Peninsula. The Archaeological Survey of South Kerry. Cork: Cork University Press. Österholm, I. and Österholm, S. 1984. The kitchen middens along the coast of Ballysadare Bay, pp. 326–45 in Burrenhult, G. (ed.), The Archaeology of Carrowmore: Environmental Archaeology and the Megalithic Tradition at Carrowmore, Co. Sligo (Theses and Papers in North-European Archaeology 14). Stockholm: Institute of Archaeology at the University of Stockholm. Patterson, W. H. 1894. Shell-mounds at Rosapenna, north Donegal. The Irish Naturalist 3, 49–51. Praeger, R. L. 1896–8. Report upon the raised beaches of the north-east of Ireland, with special reference to their fauna. Proceedings of the Royal Irish Academy 4, 30–54. Raftery, B. 1994. Pagan Celtic Ireland: The Enigma of the Irish Iron Age. London: Thames and Hudson. Raftery, J. 1944. Miscellanea. Journal of the Royal Society of Antiquaries of Ireland 44, 37–90. Reimer, P. J., McCormac, F. G., Moore, J., McCormick, F. and Murray, E. V. 2002. Marine radiocarbon reservoir corrections for the mid- to late Holocene in the eastern subpolar North Atlantic. The Holocene 12, 129–35.

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Richards, M. P. and Hedges, R. E. M. 1999. Stable isotope evidence for similarities in the types of marine foods used by late Mesolithic humans at sites along the Atlantic coast of Europe. Journal of Archaeological Science 26, 717–22. Robinson, T. 1990. Stones of Aran: Pilgrimage. London: Penguin Books. Russell, N. J., Bonsall, C. and Sutherland, D. G. 1995. The exploitation of marine molluscs in the Mesolithic of western Scotland: evidence from Ulva cave, Inner Hebrides, pp. 273–88 in Fischer, A. (ed.), Man and Sea in the Mesolithic (Proceedings of the International Symposium, Kalundborg, Denmark 1993. Oxbow Monograph 53). Oxford: Oxbow. Rynne, E. 1956. Excavations of a ringfort at Ardcloon, Co. Mayo. Journal of the Royal Society of Antiquaries of Ireland 86, 203–14. Schulting, R. J. 1998. Slighting the sea: stable isotope evidence for the transition to farming in northwestern Europe. Documenta Praehistorica 15, 203–18. Shackleton, N. J. 1973. Oxygen isotope analysis as a means of determining season of occupation of prehistoric midden sites. Archaeometry 15, 133–41. Siggins, L. 2005. Surfers blamed for West coast damage. Irish Times (20th August), 2. Waddell, J. 1998. The Prehistoric Archaeology of Ireland. Galway: Galway University Press. Waselkov, G. A. 1987. Shellfish gathering and shell midden archaeology, pp. 93–209 in Schiffer, M. B. (ed.), Advances in

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Archaeological Method and Theory Vol. 10. London: Academic Press Inc. White Marshall, J. and Walsh, C. 2005. Illaunloughan Island: An Early Medieval Monastery in Co. Kerry. Bray: Wordwell. Winder, J. M. 1980. The marine mollusca, pp. 121–7 in Holdsworth, P. (ed.), Excavation at Melbourne Street, Southampton, 1971–76 (CBA Report 33). Southampton: Council for British Archaeology. Winder, J. M. 1985. Oyster culture, pp. 91–5 in Milne, G. (ed.), The Port of Roman London. London: B. T. Batsford Ltd. Windle, B. C. A. 1911. A note on some kitchen middens in the north of Ireland. Journal of the Royal Society of Antiquaries of Ireland 41, 1–4. Woodman, P. C. 1978. The Mesolithic in Ireland: Hunter-Gatherers in an Insular Environment (BAR British series 58). Oxford: British Archaeology Reports. Woodman, P. 2004. The exploitation of Ireland’s coastal resources–a marginal resource through time? pp. 37–55 in Gonzalez-Morales, M. R. and Clarke, G. A. (eds.), The Mesolithic of the Atlantic Façade. Tucson: Arizona State University. Woodman, P. C. and Milner, N. 2001. Mesolithic middens–from famine to feasting. Archaeology Ireland 15 (3), 32–5. Woodman, P. C., Anderson, E. and Finlay, N. 1999. Excavations at Ferriter’s Cove, 1983–95: Last Foragers, First Farmers in the Dingle Peninsula. Bray: Wordwell.

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8 The Study of Fossil Insect Remains in Environmental and Archaeological Investigations: An Irish Perspective Nicki J. Whitehouse

Abstract This chapter reviews the usefulness of fossil insect remains in archaeological and Quaternary sediments. It outlines the history of the discipline and highlights the different insect groups available for analysis and their uses and contribution to the understanding of past environments. The practicalities of sampling, identification and analysis are presented. The second part of the chapter provides a comprehensive review of the available fossil insect evidence from Ireland, starting with our knowledge of climate change inferred from fossil insects, then moving onto studies which highlight the development of the Irish landscape via a series of published prehistoric archaeological sites, and including unpublished data from a new investigation at Ballyarnet Lake, in Co. Derry. Finally, the contribution of urban and rural archaeological faunas from the historic period are discussed, with particular reference to research from Dublin, such as published research on Viking and Medieval deposits and a

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new Post-Medieval assemblage from Newmarket. The importance of analyses from rural assemblages at the Early Christian rath site at Deer Park Farms, Co. Antrim, is highlighted. The chapter concludes by highlighting areas to be addressed and future research directions.

Introduction Insects potentially provide one of the most effective means of reconstructing both past environments and the details of changing climate, being very sensitive to environmental change and occupying almost every type of habitat on land and freshwater. Their diversity enables them to be utilised as proxy data for a wide variety of habitats and climatic conditions (Elias 1994, 55). As a group, their remains may be the most frequent identifiable fossils in terrestrial, waterlogged sediments and they are similarly common in anaerobic archaeological sediments. Fossil insect research (Quaternary entomology or palaeoentomology) has provided important palaeoclimatic data on the transition from arctic to temperate conditions during the Late-Glacial (e.g. Coope et al. 1998), as well as highlighting the scale of environmental changes, particularly during the last 5,000 years of the Holocene (Buckland and Coope 1991). Much of this record has been obtained through the use of palaeoentomology in archaeological investigations. Many of these have concerned rural sites, such as Neolithic and Bronze Age trackways and occupation sites (e.g. Girling 1976; 1979; 1980; Robinson 1991; 2000; Smith et al. 1997) and Iron Age enclosure sites (Chowne et al. 1986; Robinson 1993; Roper and Whitehouse 1997). Urban archaeological sites have also yielded copious insect material (e.g. Hall and Kenward 1980; Greig 1981; Kenward and Hall 1998). There

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has also been a growth of palaeoecological studies which have examined deposits not directly associated with archaeological features, usually peat or alluvial sequences, but which carry a record of human impact on the landscape. Fluvial sediments often accumulate material, particularly in secondary channels bends, backflows and pools, as well as adjacent floodplain deposits (Brown 1997; Smith and Howard 2004), such as those from Bole Ings, in the Trent Valley (Dinnin 1997) and Tiln, in the Idle Valley (Howard et al. 1999), both in Eastern England. Bogs and fens are also rich sources of fossil insect assemblages, although fen peats tend to be richer in insect remains than acid peats (Buckland 1979; Roper 1996; Whitehouse 2004). Anaerobic conditions ensure excellent preservation and the rapid built-up of deposits provides good temporal resolution. Although the focus of Quaternary entomology has undoubtedly been in Great Britain, investigations in Ireland have, over the last ten years or so, become more frequent, although they are still perhaps relatively rare compared with other areas of environmental archaeology. This is largely due to under-funding in this area, lack of specialists and, perhaps, limited awareness of the potential of sub-fossil insect data. This paper is, therefore, a timely opportunity to evaluate the published evidence and identify future opportunities. Methods associated with this approach are summarised, particularly those associated with fossil beetles, although reference is made to other groups studied, together with a review of their usefulness. Workers who have made the greatest contribution to the field include Russell Coope (Coope et al. 1979; Coope 1981), Eileen Reilly, working on archaeological deposits from Dublin and wetland sites such as Corlea trackway and Derryville Bog (Reilly 1996; 2003; Caseldine et al. 2001),

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Harry Kenward investigating the faunas from Deer Park Farms, Co. Antrim (Kenward and Allison 1994; Allison et al. 1999) and more recently, the author (e.g. Plunkett et al. 2004; Hall et al. 2005; Whitehouse 2006). Not all research is, as yet, unfortunately, available in the public domain. Figure 8.1 shows the location of the Irish sites referred to in the text. Coleoptera nomenclature in the text follows Lucht (1987), while plant nomenclature follows Stace (1991). Apart from the discussions of Late Glacial and earlier records, where dates are expressed as calibrated radiocarbon dates BP, dates are expressed as cal. BC/AD where possible, to provide easy comparison with archaeological records and dendrochronological dates.

Principles and Methods Carl Lindroth and fellow Scandinavian entomologists established the foundations of the modern discipline in the 1930s and 1940s, but in the mid 1950s research activity moved to Britain and the geology department at Birmingham University (Morgan and Morgan 1987). Here, Professor Russell Coope began studying Quaternary insect fossils from Upon Warren, an interstadial site in the British Midlands dated to c. 40,000 radiocarbon years ago (Coope et al. 1961). By making patient comparisons with modern specimens, he matched most of the material to modern species. Coope showed that insects had remained evolutionally stable in their morphology and their environmental requirements throughout the whole of the Quaternary period (Coope 1970). Indeed, evidence for evolutionary change is extremely rare from Quaternary insect assemblages. John Matthews (1970) working in Alaska, has been able to show changes in Late Pliocene and Early Pleistocene fossils, but even here, these

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are only slight. Research from the far north of Greenland has confirmed Matthews’ work (Böcher 1986; 1997). It seems that the overall composition of the assemblages of insect species which broadly occur today, at least in the temperate zones, were established during Late Tertiary times, with very similar fossil insect assemblages recovered during different glacial, interglacial and interstadial climatic episodes (Elias 1994).

Figure 8.1: Location map of Irish sites discussed in the text. Insect groups identified commonly include the beetles (Coleoptera), because their robust exoskeleton survives well in waterlogged deposits, leaving many of their diagnostic 325

features still evident (Fig. 8.2). There are about 4000 species in Great Britain and c. 3000 in Ireland, which means that identification is still very much of a specialist activity. Other insect orders are, however, increasingly being analysed, such as larval head capsules of the Chironomidae (Diptera) (commonly known as ‘non-biting midges’) (Fig. 8.3). This group have recently received considerable research attention (e.g. Walker et al. 1991; Brooks et al. 1997a; 1997b; Brooks and Birks 2001; Langdon et al. 2004; Brooks 2006). Although their use in archaeological investigations has been limited so far, they show considerable potential (Ruiz et al. 2006), as discussed further below.

Figure 8.2: Fossil beetle assemblage associated with Old Croghan Man, Croghan Bog (Photo: N. Whitehouse).

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Work on other Dipterous (fly) remains is being pioneered through the work of Pete Skidmore (1995) and more recently Eva Panagiotakopulu (2004). Trichoptera (caddis) have also received some attention (e.g. Wilkinson 1984; Greenwood et al. 2003). Hymenoptera (bees) are often well represented and groups such as the Formicidae (ants) merit specialist attention (e.g. Robinson 1993). Increasingly, there is the use of multiple insect groups to refine reconstruction of past environments, particularly where high quality data is required concerning periods of rapid environmental change. A good example of this approach is provided by the Kråkenes Project, which has investigated the ecosystem of this lake in western Norway during the Late Glacial and Early Holocene (Birks et al. 2000). On archaeological sites, ectoparasites of animals and humans, such as lice and fleas are commonly recovered, particularly where there is preservation of good organic material (e.g. Allison et al. 1999). Other arthropod groups such as mites (Acarina) have received some study, notably by Karppinen and Koponen (1973; 1974) and Schelvis (1987; 1997) in the investigation of archaeological deposits.

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Figure 8.3: Chironomid head capsules from Lough Nadurcan: Monopsectrocladius sp. (left), Dictotendipes sp. (right) (Photo: J. Watson). Reconstruction of past environments operates upon on the major assumption that the ecological requirements of insects have not dramatically changed. The fact that groups of species have consistently been found together suggests that the ecological requirements of most species have not altered (Kenward 1976). However, there are considerable difficulties in establishing the ecological requirements of single species and their significance in fossil faunal assemblages. For instance, the available field data may not cover all available habitats and may include casual records. Even when the biology of species is known in some detail, this may not cover all the suitable habitats, especially when microhabitats may provide suitable locations where the overall situation may provide a rather different ecological environment (Kenward 1978). It is recommended that a large number of taxa and individuals are utilised, which when examined together provide a picture of past environments and conditions, an approach known as the ‘mosaic’ approach (Kenward 1975; 1976). Another consideration concerns the depositional context of an assemblage, and whether the faunal assemblage constitutes a largely in situ assemblage (autochthonous), one which is primarily brought onto site (allochthonous) (e.g. material transported through flooding or insects brought onto a site through human-related activities such as the transport of animal bedding) or whether a mixture of processes has deposited material. This is frequently the case for archaeological material, where a component of insect material 328

represents the population living close to the burial deposit and other material which may have been brought onto the site. Many human activities may influence the transport of such material. Kenward and colleagues provide a review of some of the processes of transport (Kenward 1985; Hall and Kenward 1998), whilst Buckland et al. (1994) consider the different components in Norse floor layers in Greenland and Iceland. Separating out these different components is particularly crucial for the understanding of an archaeological assemblage, whilst in palaeoecological work this additional information may be considered an asset (Coope 1977). An important indicator of the depositional history of fossils is their state of preservation (e.g. Kenward and Large 1998). This can provide clues, amongst other things, of differential preservation, separate origins of ecological components and episodes of dehydration. The scale of environmental reconstruction required is an important consideration when deciding whether insect fossils should be used in the investigation of a site. Fossil insects will usually provide a largely local rather than regional picture of the environment, in contrast to palynology which will tend to provide a regional picture of environmental change. This combination often makes the twinned approach of using pollen and fossil insects a useful one and is elegantly exemplified in a study by Brayshay and Dinnin (1999). The combined approach of using plant macrofossils and insects is one which has been used very successfully in the analysis of urban archaeological deposits such as those in York (e.g. Kenward and Hall 1995) and elsewhere (Hall and Kenward 1980).

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Practicalities: Sampling and Analysis of Fossil Insect Material Sampling of material suitable for fossil beetle analysis entails the removal of material from an exposed section or bulk sampling from an archaeological or palaeoecological context (e.g. cess pit; ditch; fossil tree rot holes). In the case of the latter, samples are usually removed in 5–10 cm thick contiguous ‘slices’, usually of at least 5–7 litres, taking care not to cross stratigraphic boundaries. Depending on the research questions being posed, and whether these require fine resolution data, even finer sampling may be undertaken (e.g. 3–4 cm slices), although this may not always be practical, but may be desirable with palaeoclimatic investigations. Occasionally it is possible to remove blocks of deposit (e.g. 50 cm x 50 cm), when non-friable deposit is being sampled. This approach allows the investigator to sample in the laboratory particular points in the stratigraphy and is preferable to the former approach. Sampling methods for caddis analysis are very similar to beetle analysis, using similar quantities, at similar resolution. In archaeological excavations or single palaeoecological contexts, large bulk samples of contexts of interest are recommended. The standard recommendation by English Heritage (2002), for instance, is that specialist bulk samples should be in the order of 20 litres, to allow for sub-sampling of material for different kinds of analyses. Often it may be most appropriate to remove the complete context, such as the fill of a storage or cess pit. In the case of small insects, such as the chironomids, much smaller amounts of sediment are normally sufficient, typically 0.5–2 cm3, to yield the 50–100 head capsules required, 330

although palaeochannel deposits may require larger amounts of 200 cm3 or more (Ruiz et al. 2006). Chironomids are ubiquitous in freshwater habitats and will be abundant in lake sediments, in-filled lakes and floodplains (e.g. Gandouin et al. 2006). Material for analysis is thus normally extracted using a sediment corer, such as a Livingstone. The analysis of archaeological material entails the recovery of small bulk samples from contexts of interest. As in the case of all sampling strategies, types of contexts and deposits and how they are to be sampled depends upon the research questions being posed by the investigation. It is therefore imperative that an environmental specialist is involved at the planning stage, enabling the archaeology and environmental aspects of the project to be fully integrated. English Heritage (2002) has produced an excellent booklet specifically aimed at archaeologists and provides a run-down of approaches and sampling strategies. Equivalent guidelines have very recently been prepared for Ireland (Institute of Archaeologists of Ireland 2006). The extraction of fossil beetles follows a technique adapted by Coope and Osborne (1968) and outlined in full by Buckland and Coope (1991). Up to 5 litres of material are removed for each sample, although more may be required depending upon the deposit being studied. In very organic-rich deposits considerably less may be sufficient; a sub-sample of half or a litre will often be informative about the density of preserved fossils and a good indication of how much sediment may be required for full analysis. Each sample is disaggregated over a 300 micron (μm) sieve to remove any clay, silt and sand fraction from the sample. Paraffin (kerosene) is mixed to the remaining material and cold water

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is added. The resulting ‘flot’ is then poured off, washed in detergent, rinsed and stored in ethanol. Sorting for insect remains is carried out under a binocular microscope at x10–40 magnification. The amount of time devoted to this activity may vary from between several hours to several days, depending on the volume of the flot. Problematic samples tend to be those associated with fen and raised peats, where often almost the entire sample of several litres may have to be sorted by hand. For the extraction of caddis, the same paraffin flotation method is used, but with the addition of a smaller sieve of 125 microns to collect smaller fragments (Greenwood et al. 2003). Extraction of chironomids follows the techniques of Hofmann (1986). Firstly, samples are deflocculated in hot 10% potassium hydroxide (KOH), and then sieved through a pair of nested sieves, usually 90 μm and 180 μm. Chironomid head capsules are then hand-picked from the remaining fraction. Keeping the two size fractions separate makes sorting easier. If, however, a large amount of material still remains, further chemical treatment is possible (Walker 2001). The paraffin flotation technique described above has also been found to be very effective (Ruiz et al. 2006). Midge head capsules are usually counted to a minimum of at least 50, although accuracy of palaeoenvironmental reconstructions are strengthened with counts of c. 80–100 (Hieri and Lotter 2001; Quinlan and Smol 2001), and mounted directly onto slides or dehydrated in 99% ethanol before mounting in Euparal or another suitable mounting medium. Head capsules are usually identified based on mentum (see Fig. 8.3), ventromental plates and other structures according to Cranston (1982), Hofmann (1971), Wiederholm (1983) and Rieradevall and Brooks (2001). It is usually possible to

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identify taxa to genus or groups, whilst identification to species or species group level has become increasingly possible due to advances in identification guides for fossil midge head capsules (Brooks 2006). The identification of other insect fossil material is carried out through the use of European entomological keys and through direct comparison with a range of modern comparative material (Buckland and Coope 1991). Most researchers will require access to a good museum collection. After identification, the minimum number of individuals (MNI) from the parts recovered are listed and counted. Where preservation levels are good, species level identification is possible for about 70% of the fauna, allowing very detailed environmental histories and reconstructions to be made. Where many samples are to be examined, however, it may not always be necessary or desirable to identify all samples to species level, as rapid scanning techniques can often be informative without the time requirement associated with full analysis (Kenward et al. 1986; Kenward 1992). Conversely, this approach may mean that occasionally significant species may be overlooked, although this is unlikely where experienced researchers are concerned. Rapid scanning techniques should only be undertaken by very experienced workers. For caddis, identification is mostly based on shape, size and colour pattern of frotoclypeal apotome, as matched against reference material and standard texts (Greenwood et al. 2003). The ‘mosaic’ approach is usually used in the interpretation of many fossil insect assemblages. This may be limited to a discussion of the significance of particular species and their habitats, but can extend itself to the classification of

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assemblages into groups of species, such as aquatics, wetland species, wood and tree species and so on (e.g. Kenward 1978; Robinson 1991; 1993; Kenward and Hall 1995; Whitehouse 2004). The setting up of an ecological habitat and fossil beetle database at the University of Sheffield, now based at the University of Bournemouth, has greatly facilitated and contributed to the use of this approach (cf. Sadler et al. 1992; Buckland et al. 1997). It should, however, be noted that modern descriptions of habitat preferences and ecological groupings cannot necessarily be applied to archaeological studies without modification and have to be interpreted by a trained practitioner. The division of data into categories is, however, essentially an interpretative tool and suffers from certain limitations, including the subjective nature of selection, assignment and interpretation of categories (Whitehouse 2004). The interpretation of the resultant diagrams always should be done by reference to the species list. Other types of analyses include the use of indices to examine species diversity (e.g. Kenward 1978; Roper 1996), sample similarity (Perry et al. 1985; Whitehouse 2004), and rank order curves (Kenward 1978; Roper 1996). A further step in palaeoenvironmental interpretation can be achieved through indicator groups and species associations, where a suite of species might be expected to be found consistently under certain conditions. This type of approach has been developed by Kenward and colleagues (Kenward et al. 1986; Kenward 1997; Kenward and Hall 1997; Hall and Kenward 1998), who have attempted to identify the origin of deposits from their ‘signature fauna’. Relatively few multivariate ordination techniques have been used in the analysis of fossil beetle assemblages (e.g. Perry et

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al. 1985; Cong and Ashworth 1987; Perry 1987), although recent work has highlighted the value of these approaches. Carrott and Kenward (2001) and Kenward and Carrott (2006) have used detrended canonical correspondence analysis (DCCA) for separating different ecological groups in the analysis of urban assemblages from York, whilst Whitehouse (1998; 2004) used correspondence analysis to explore mire ontogeny at Thorne and Hatfield Moors, south Yorkshire, to establish similarities between sites and samples as well as the frequency and association of common species. These approaches suggest there is considerable potential for the use of multivariate statistics to study fossil coleopteran data sets, particularly where relationships between species, samples and sites are being investigated. Such analyses require large data sets, so are most suitable for the analysis of urban archaeological assemblages, or where multiple sites have been examined. The analysis of fossil midges, in addition to using similar ordination approaches such as those described above (e.g. DCA, PCA), also use transfer functions to infer environmental conditions, based on modern training sets. This is a well-established method which has been used by researchers to reconstruct a wide range of environmental variables from different proxies. Birks (1998) provides a review of the principles involved. Performance measures are applied in order to test the robustness of results. Results from these analyses suggest that each midge lives within a narrow temperature range, and counting the relative abundance of different species can pinpoint summer temperatures to within 1–2 °C. Midges can respond fast to temperature changes as they fly and reproduce in less than one year. The analysis of chironomids is also used extensively for bio-monitoring, for

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instance, in the study of lake eutrophication, productivity, pH, water levels, toxicity and physical disturbances (Brodin 1986; Brooks et al. 2001).

Quaternary Entomology and Climate Change One of the most important research areas of Quaternary entomology lies in the field of climate change. A succession of studies in the early 1970s by Coope and co-workers showed that beetles were responding to a series of very rapid climate changes of greater amplitude and speed than those deduced from the pollen record (Ashworth 1972; 1973; Coope and Brophy 1972; Osborne 1972; 1980; Coope and Joachim 1980). The botanical record is impeded by the slower migration rates of plants, particularly of trees. Through work on many sites, Coope was able to produce a composite curve showing climate through much of the Late Glacial (c. 13,000 BP–10,000 BP) (Coope and Brophy 1972; Coope 1977; 1994; Walker et al. 1993; Lowe et al. 1999). The rapid changes from cold to warm conditions during the this period inferred by this work, possibly in less than fifty years during the Younger Dryas-Holocene transition (Ashworth 1972; 1973; Osborne 1974; 1980), have been confirmed by the Greenland ice cores which suggests abrupt and rapid warming, perhaps within 10–20 years (Dansgaard et al. 1989). There is a particularly good correlation between the palaeoclimatic curve derived from fossil insect sites in the British Isles and those derived from the Greenland ice core and other proxies (Coope and Lemdahl 1995; Lowe and Walker 1997), although local as well as regional influences can have important effects upon results (Coope and Lemdahl 1995; Coope et al. 1998; Vandenberghe et al. 1998).

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The quantification and standardisation of the palaeoclimatic data have been aided by the Mutual Climatic Range (MCR) method (Atkinson et al. 1989). The application of the MCR technique has seen the production of palaeoclimatic curves for almost the last 45,000 years (Lowe and Walker 1997), at least for northern Europe. Elias (1996; 1997; Elias et al. 1996) has also applied MCR to insect assemblages from the American continent, whilst in the southern hemisphere Marra et al. (2004), working in New Zealand use a new technique (Maximum Likelihood Envelope or MLE) which works on similar principles but which accommodates for the uneven state of knowledge of the present day New Zealand fauna, mathematically tests the robustness of each calculation, and makes any necessary adjustments. The basic assumption of these approaches is that if the present climatic tolerance range of a beetle species is known, then fossil occurrences of that species imply a palaeoclimate which lies within the same tolerance range. The palaeoclimate is reconstructed by using the mutual intersection of modern climatic ranges of selected species in the fossil record (Atkinson et al. 1989). Coleoptera are especially suitable for this technique as they are a varied group in which many species show fairly well defined tolerance ranges (Elias 1994). Carnivorous and scavenging beetle species are usually utilised as they are able to respond more rapidly to climate change and they are not tied to specific types of vegetation. MCR reconstructs mean July (warmest month) temperature (TMAX) and mean January (coldest month) temperature (TMIN). It is possible to test the accuracy of MCR by reconstructing climates from living beetle assemblages. This has been carried at a number of sites in Europe, Siberia and North West Canada (Atkinson et al. 1989). The results show

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that the reconstructed median is lying slightly above the true value of TMAX, whereas with TMIN the median overestimates the true value in colder climates but underestimates it at sites with mild winters. The MCR results can be corrected to take into account these differences (Walkling and Coope 1996). The Late glacial transition (LGIT) is well documented in Ireland (Coope et al. 1979; Cwynar and Watts 1989; Andrieu et al. 1993) with clear evidence for the Late Glacial Interstadial/Woodgrange Interstadial and Younger Dryas Stadial/Nahanagan Stadial, though the precise timing, duration and magnitude of these oscillations is uncertain (Andrieu et al. 1993). The abundance of suitable deposits, many still unstudied and of high resolution, suggests that Ireland has considerable potential to play a significant part in climate change research. The limited work carried out on the Late Glacial and Early Holocene in Ireland is confined to published and unpublished work undertaken by Professor Russell Coope, formerly at Royal Holloway College, University of London, and unpublished work by the author and her students. Of the published work, two sites cover this period–Shortalstown, Co. Wexford and Drumurcher, Co. Monaghan–while a further three unpublished sites–Finglas River, Co. Tipperary; Craddenstown, Co. Meath; Ballybetagh Bog, Co. Wicklow–also exist (see Coope and Lemdhal 1995; also Turney et al. 2000). From Shortalstown, Co. Wexford, Coope (1971) investigated two samples; the uppermost dated to 12,160±180 BP (I-4963; 13,500–11,700 cal. BC). Although there are a few species which have predominantly northern distributions (e.g. Pelophila borealis Payk., Patrobus septentrionis Dej. and

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Dytiscus lapponicus Gyll.), they all still live in Ireland today and the majority of the fauna consists of eurytherm species–those which are able to tolerate a wide range of temperatures–as well as a large number of species which are today rare or absent from Northern Europe (e.g. Bembidion minimum F., Hydroporus granularis L., Colymbetes fuscus L., Donacia cinerea Hbst.). Many taxa are inhabitants of stationary fresh water, as well as those which live in accumulating plant debris in ponds. A rich littoral vegetation is implied by the beetles, there is no evidence for tree-dependant species or warmth-loving species, although Coope (1971) suggests a climate little different from that of Ireland at the present day, with an average July temperature of c. 15–16 °C. Coope interprets the faunas as belonging to the Bölling phase of the Interstadial, where insect faunas indicate a climate at least as warm as the present. In contrast, insect faunas from Drumurcher, Co. Monaghan (Coope et al. 1979), date to the Younger Dryas (10,515±195 BP; Birm-239; 11,100–9,700 cal. BC) and the Early Holocene. The Younger Dryas assemblages are dominated by beetles associated with arctic and melting snow bed conditions, such as Bembidion fellmanni Mnh., Nebria nivalis Payk., Diacheila arctica Gyll., and Helophorus glacialis Villa. Moss and leaf litter debris are also indicated by small staphylinid beetles such as Olophrum fuscum Gr., O. boreale Pk. and Arpedium brachypterum Gr. Many of these taxa are today restricted to the most northerly areas of Europe. The contribution of the Irish record to our understanding of climate change is extremely important, not just in terms of understanding past climates and how these would have impacted upon prehistoric populations, but also within the

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wider context of global climate change. We now know that there are regional differences in the Late Glacial climate of northern Europe based upon beetles (Coope and Lemdhal 1995; Walkling et al. 1998), and that there is very good correlation between the climatic curve for the wider geographic area of the British Isles and that from the Greenland ice core and other proxies. This suggests that there are causal links between North Atlantic surface water circulation (Thermohaline Circulation) and climatic conditions on the adjacent continent. Effects would be most prominent in these areas closest to the ocean margin, provided there were no other overriding counter-balances. This idea can be tested most effectively in Ireland where periods of rapid climate change may have been most felt in westerly localities, adjacent to the North Atlantic. The prevailing westerly airflow, combined with the strongly controlled maritime climate and an absence of any significant ice cap at the time of the Late Glacial transition (McCabe 1987), allow climatic changes to be identified and quantified free from any effects of ice and continentality in the east. In fact, the Irish record has played relatively little part in this debate, despite being in an ideal location to examine some of these issues. Work is now underway at several sites to examine the sensitivity of Ireland to these changes and how these compare with Great Britain and elsewhere across northern Europe via a PhD studentship undertaken by Jenny Watson, based at Queen’s University Belfast, under the supervision of the author and Steve Brooks, Natural History Museum, London. Improving chronological methods such as the identification of rhyolitic and basaltic microtephra horizons within Late Glacial minerogenic sediments (Turney 1998) allow the correlation of sequences from Ireland with sites across Europe and with ice cores. Recent research at sites such as Roddans 340

Port, Co. Down (Morrison and Stephens 1965), has indicated the presence of several marker Late Glacial tephra horizons in deposits in the north of Ireland (Turney et al. 2006) and offers the potential for high-precision correlation of palaeoclimatic records throughout the North Atlantic region. More recently, there has been considerable success in reconstructing past climates using non-biting midges. Brooks examined midges with considerable success from a Late Glacial chironomid sequence from Whitrig Bog, south-east Scotland (Brooks and Birks 2000). Brooks’ temperature curve reveals dramatic fluctuations in the relative populations of coldwater and warm-water taxa for 5000 years after the end of the last ice age c. 14,000 BP. Chironomid-inferred transfer functions are based on 109 Norwegian modern lakes. Four interstadial oscillations were identified as well as a gradual warming throughout the Younger Dryas (Brooks and Birks 2000). The largest fluctuation is the Younger Dryas; the midge remains suggest that Scottish summer temperatures at the start of the Younger Dryas crashed by about 10 °C over just a few decades. These results corresponded closely with the oxygen isotope curve derived from the GRIP ice core, although there is some debate concerning the global extent of this event (e.g. Turney et al. 2003). More recently, other sites have been investigated for their midge record, such as at Howes Water, near Liverpool (Marshall et al. 2002; Bedford et al. 2004), and in Ireland work is now well underway at Lough Nadurcan, Co. Donegal, and Roddans Port, Co. Down (Watson unpub.; Whitehouse and Brooks unpub.). Despite the success in examining Late Glacial climatic change, Holocene climatic change has been less easy to infer from the insect record. For example, terrestrial floral evidence

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indicates a cool start to the Holocene, but the beetle evidence suggests that this period may have been the warmest (Osborne 1997), a fact corroborated by the Greenland ice core data (Johnsen et al. 2001). There has been perhaps more success looking at climate change using midges, but even these are beset with interpretational problems relating to the influence of pH on lake systems and the fact that the amplitude of climate changes in the Holocene is of the same magnitude as the error margins associated with the transfer functions used (Brooks 2006). From the mid-Holocene onwards, palaeoecological studies highlight the increasing scale and extent of environmental change. Data clearly indicate that not only is human impact of considerable importance, but that it may swamp and mask low magnitude climatic events. Osborne (1969; 1976; 1982) attempted to examine the distribution of beetles linked to habitats which are less subject to human disturbance. He concluded that there was some evidence to suggest that between four and three thousand years ago summer temperatures were higher than the present day, declining to present levels during the Iron Age and remaining more or less constant until the ‘Little Ice Age’ (Osborne 1982; Girling 1984). The effects of this climatic deterioration have still to be fully evaluated (see Buckland 1975; Buckland et al. 1983; Girling 1984; Dinnin 1997; Osborne 1997; Wagner 1997). Buckland and Wagner (2001) suggest that this episode may have had some impact upon insect faunas, but draw attention to the fact that very few deposits spanning this period have been investigated, where a clear climatic signal would be evident, whilst a recent review by Kenward (2004) suggests that there is some evidence to support the idea that bugs at least may have been affected adversely by the Little Ice Age.

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Thus, despite the wealth of information, a full understanding of the complexity and interplay between climatic and human factors that cause change remain elusive.

Quaternary Entomology and Holocene Environmental Change Quaternary entomology has also highlighted the scale and extent of environmental change during the Holocene. Much of the work relates to Britain, but there is an increasing Irish data set. Evidence from Britain suggests that an ancient tree and woodland fauna had already started to arrive within the first 1,000 years of the beginning of the Holocene (Dinnin and Sadler 1999). As tree species expanded from Europe and habitats became more diverse, its associated fauna moved northwards over the next few thousand years, including a number of specialist saproxylics that no longer live in Britain and Ireland. Recent research by the author explores the mechanisms by which many of these species arrive (Whitehouse 2006). Turning to the Irish record, very little fossil insect work covers the environmental record representing the early part of the Holocene. Several samples from Drumurcher, Co. Monaghan (Coope et al. 1979), included material dating from the first few hundred years of the Holocene. The faunas suggest open country with few or no trees, but already showing an increase in humus content of the soil. Rapid climate amelioration is indicated by the beetles, with an average July temperature of about 10 °C at c. 11,100–9700 cal. BC (10,515±195 BP; Birm-239). Work undertaken by Karen Rogers (2004) as part of an undergraduate thesis project on inter-tidal peats from Strangford Lough, Co. Down, indicates a tree-dominated environment, with plenty of

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pines. The peats have been dated elsewhere in the Lough to between 7320–7070 cal. BC (9270–9020 cal. BP; 8173±34 BP; UB-4587) and 7030–6600 cal. BC (8980–8550 cal. BP; 7894±35 BP; UB-4581) (McErlean et al. 2002). The lack of beetle taxa associated with deciduous trees is noticeable, but their absence is much more likely to be related to local edaphic conditions associated with the study area and may imply little about the wider environment. The species list included several beetles which are not on the current Irish list, including Hylastes ater (F.), H. angustatus (Hbst.) and weevil Rhyncolus ater (L.). All species are still present on the British list, the former two living in southern England, whilst the latter is mostly confined to the Caledonian forests in Scotland. No other sites have been investigated which represent the very Early Holocene period, between c. 10,000–6000 cal. BC, and this is clearly a period that would benefit from further investigation. A series of new projects undertaken and in progress by the author over the last few years provides some important new data concerning the Later Mesolithic period onwards, including work from Sluggan Bog, Co. Down, Derragh (on the shores of Lough Kinale), Co. Caran, and Ballyarnet Lake, Co. Derry. Sluggan Bog in Co. Down has been subject of several palaeoecological investigations (Smith and Goddard 1991; Pilcher et al. 1995; Lowe et al. 2004). Peat initiation at the site began during the Late Glacial, continuing through the Holocene, during which time c. 6 m of peat accumulated. Around 6300–5500 cal. BC and again at 3350–3250 BC (dendro date), a pine woodland invaded the surface of the bog (Pilcher et al. 1995), indicating that the mire had become sufficiently dry to allow colonisation by trees onto its surface.

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Four samples associated with this layer, dated to between 6500–6000 cal. BC, were processed for fossil beetle analysis (Whitehouse unpub.). The insect species recovered include beetles typical of lowland raised bogs and a community characteristic of areas of old pine woodland, including three species which are not included on the current Irish list of Coleoptera–the Urwaldrelikt species Rhyncolus elongatus Gyll., R. sculpturatus Waltl. and the very rare Bothrideres contractus. Dajoz (1977) regards the last as a Tertiary relic under threat of extinction and an Urwaldrelikt (Vogt 1967). The first two taxa have also been recovered associated with pine trees from Ballymacombs More, Co. Antrim (Whitehouse unpub.). They mostly inhabit scattered localities throughout central and southern Europe, reaching southern Fennoscandia (Whitehouse 2006). These are first fossil records for these species in Ireland. They are also not on the current British list, but have been recovered from fossil contexts, thereby indicating their former wider occurrence (Whitehouse 2006). New investigations by the author in association with the Irish Discovery Programme at the Derragh waterlogged Late Mesolithic platform site, placed at the junction of the former River Inny and Lough Kinale, Co. Cavan, will provide some valuable new data for the period between c. 5400–4300 cal. BC. Work is still very much at a preliminary stage, but results so far are very encouraging. As Brown et al. (this volume) highlight, such landscape and ecosystem interfaces represent areas of considerable archaeological and palaeoenvironmental potential. A recent project funded by the Environment and Heritage Service (DOE: Northern Ireland) and the British Academy

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has allowed an investigation of the conditions of settlement associated with a Middle Bronze Age settlement site in the fen peats that surround Ballyarnet Lake, Co. Derry. The excavation established that the structural remains of the lake settlement are represented by a timber platform overlying fen peat and retained by a palisade. The archaeological importance of the site is outlined by O’Neill et al. (2003; submitted). The environmental aspects of the project were designed to address the wider context of the lake settlement and eco-dynamics. Detailed palaeoenvironmental studies of early prehistoric wetland settlements and their contexts are generally lacking throughout Ireland and the project provided an opportunity to address this gap in the archaeological record (Plunkett and Whitehouse 2004; in prep.) and to contribute to the understanding of prehistoric lake settlement in the north of Ireland. The surrounding area has a long history of prehistoric activity, including a nearby Early Neolithic settlement complex at Thornhill (Logue 2003) which occurs nearby. Palynological, coleopteran and plant macrofossil analyses on the peats adjacent to the Bronze Age settlement site have provided detailed insights into the context of foundation and abandonment of the site. The fossil beetle material is typical of a faunal assemblage from the margins of a lake. Many taxa are associated with aquatic and semi-aquatic environments and wet reed vegetation, also represented in the pollen or plant macrofossil records (Plunkett and Whitehouse 2004). The earliest samples precede the occupation of the site and date to the Neolithic period and include a variety of ancient woodland species (including the extirpated Rhyncolus sculpturatus Waltl., which has already been discussed above). However,

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increasing levels of meadow, grassland and dung beetle taxa, together with decreasing levels of tree-associated beetles suggest clearance of the wider landscape. There are also obvious hydrological shifts in evidence, with drying out of the site before human use of the area. Use of the site clearly coincides with a period of drying out of the fen adjacent to the lake. A series of samples associated with the archaeological horizons have also been examined. There are culturally-favoured taxa within the assemblages, including dry mould-feeders such as Lathridius minutus, which is often associated with hay/straw and a variety of dung beetles. There are several pasture/grassland indicators, whilst tree and wood components are restricted to a few feeders on oak and species which often inhabit worked timber, such as the furniture beetle Anobium punctatum. All the indications are that the archaeological site is located in a much cleared landscape compared with previously, although the intensity of the use of this landscape is far from clear. Several other wetland investigations from raised bogs dating from the Neolithic through to the Iron Age provide other perspectives on the impact of human activities across the Irish landscape, as inferred from the fossil beetle record. Here, I will consider just two of these studies; the investigation of material associated with the trackway at Corlea, on the Mountdillion Bog complex, Co. Longford (Reilly 1996), and the research project at Derryville Bog, part of the Lisheen Archaeological Project, Co. Tipperary (Caseldine et al. 2001). Excavations at Corlea, between 1985 and 1991, revealed numerous wetland archaeological sites, particularly trackways preserved in the peat, dating from the Neolithic through to the

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Iron Age (Raftery 1996). Several samples from the surfaces of the Neolithic trackways Corlea 9 and 10 were studied for their insect fauna (Reilly 1996). The fauna was dominated by raised mire specialists, many of which indicated that fully ombrotrophic conditions had developed by the time the trackways were laid down. There are surprising few obligate wood specialist beetles which might be expected associated with such a trackway. Between 1995 and 1998 the Lisheen Archaeological Project was undertaken at Derryville Bog on behalf of Minorco Lisheen Ltd. (Caseldine et al. 2001). The project funded an integrated study of both the palaeoecology and archaeology of this wetland landscape. Numerous Bronze and Iron Age sites were also excavated on the western margins of the bog. Summaries of the results of the archaeological work and the palaeoecological work have been published (Caseldine et al. 2001). The fossil beetle work, carried out by Eileen Reilly, alongside other proxies, indicates distinct landscape spatial trends. On the eastern side of the bog, it seems that primary or sub-primary woodland survived during the Bronze Age, together with its associated fauna, although some areas appear to have been given over to pasture. In contrast, on the western margins of the bog, species associated with cultivation, grassland and dung were evident and there were no ancient woodland taxa. This interpretation is in line with archaeological evidence from the dry land areas, which shows that there was consistent settlement activity on the western margin of the mire, with very little activity indicated on the eastern margin (Caseldine et al. 2001). Many notable species of Coleoptera were recovered during the course of this investigation (Caseldine et al. 2001),

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including the non-Irish Prostomis mandibularis (F.). This beetle is viewed as an Urwaldrelikt (ancient woodland relict) by Palm (1959) and Horion (1960), living in just a few, more or less isolated strong-points of primary woodland, attacking wood in the final stages of decay. Today, its nearest living relative is living somewhere in France; Caseldine et al. 2001, figure 6, provide a distribution map of its current distribution, but in fact its modern distribution is more extensive, including Switzerland (Gistl 1829), several different regions across Italy (Porta 1929) and eastwards into Slovenia (Whitehead 1992; see Whitehouse 2006 for further details). Its recovery in these deposits, together with other locally ‘extirpated’ taxa from Sluggan Bog, Ballymacombs More and Ballyarnet Lake underlines the loss of several important elements from the Irish fauna. In Britain, the demise of many of these species has been attributed to the combined loss of undisturbed woodland and tree habitats and particularly of dead wood. The apparent poor mobility of many of these saproxylics species (cf. Warren and Key 1991) may have played an important part in their decline and extirpation (Buckland and Dinnin 1992; Whitehouse 1997; 2006), particularly with the onset of woodland fragmentation and the loss of continuous woodland corridors (Whitehouse 1998; 2006; Smith and Whitehouse 2005). Woodland history, management and temporal continuity of habitat also appear have been significant components in the maintenance and survival of many of these saproxylic communities. The loss of particular types of woodland, such as pinewood and its associated habitats, either through successional competition, decline in woodland fires and/or the development and expansion of peatlands, appear to have been an important contributory factor for some species

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(Whitehouse 1997; 2000; 2006). Climate change may also have been a strong causal factor (Buckland 1979; Whitehouse 1997; Dinnin and Sadler 1999; Whitehouse 2006). It thus appears that a complex combination of anthropogenic, edaphic and climatic changes probably caused the extirpation, or at least reduction, in the distribution of numerous wood-dependant invertebrates, bringing with it a dramatic increase in elements associated with open, disturbed ground and cleared landscapes. The effect of deforestation on the aquatic environment resulted in a change in the sedimentation regimes in major rivers, and drastically altered the communities of water, especially riparian beetles (Osborne 1988; Smith 2001; Smith and Howard 2004; Greenwood and Smith 2005). In Britain, many of these effects are seen from the Neolithic period onwards, with both pollen and fossil insect evidence suggesting that by the Bronze Age (c. 2500–800 cal. BC; 4000–2700 BP) a significant reduction in primary woodland had occurred (e.g. Robinson 1991). In consequence, by the Iron Age (c. 800 cal. BC–43 cal. AD; 2700–1900 BP) ancient woodland beetle species appear to represent an insignificant faunal element (Osborne 1972; Girling 1982; Robinson 1993). In Ireland, we are still a long way from having any real understanding of the history of clearance and human impact on the landscape, inferred from the beetle record, but it is likely that many of the above factors played an active role in the disappearance of species, although there seem to have been local differences in terms of the importance of factors and in the timing of disappearance of species. These are explored in further detail by Whitehouse (2006). Effects of deforestation on the aquatic environment remain largely unstudied, although suitable deposits exist. Brown et al. (this

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volume) highlight the usefulness of palaeoecological data derived from palaeochannels and other floodplain deposits for identifying episodes of land clearance, farming and management in areas of floodplains in contrast to raised mires which tend to be more distant from archaeological sites. Research undertaken at Lough Neagh has highlighted this potential (Plunkett et al. 2003; 2004; see Plunkett and McDermott, this volume).

Rural and Urban Settlement Assemblages The identification of insects from archaeological deposits has been carried out occasionally since the mid-nineteenth century, but it was only after the publication of Coope and Osborne’s (1968) work on the fauna from the Roman well at Barnsley Park and Osborne’s (1971) study of Roman Alcester that their potential for the investigation of immediate archaeological environments was realised. The technique of looking at archaeological deposits has been most consistently applied at York through the work of Harry Kenward and Paul Buckland. The York results provide the best examples of what can be achieved on a large number of sites by the careful integration of entomological data with other lines of evidence (Buckland et al. 1974; Hall and Kenward 1990; Kenward and Hall 1995). For example, many insect species associated with decomposing matter are weakly to strongly synanthropic–favoured by, or dependant upon, habitats created by human occupation and activity. Thus, an examination of insects preserved within archaeological deposits can provide a wealth of information about the conditions in which people lived (e.g. Kenward and Hall 1995; Kenward 1999).

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In Ireland, there have been a growing number of investigations concerned with the insect fauna associated with urban settlement, particularly from Dublin. Coope (1981) examined two samples from the excavation of an eleventh-century Viking house at Christ Church Place, Dublin. He found an abundance of species which occur in fermenting vegetable refuse, including the synanthropic Aglenus brunneus (Gyll.), which appears to require mould growth associated with decaying organic matter. Many of the taxa would be at home in a building with a thick carpet of fermenting vegetation, which would provide them with acceptable habitats and warmth. Coope suggests that that this squalid, fermenting carpet was perhaps deliberately contrived by the inhabitants to maintain warmth within the building. The fauna is very similar in composition to those found in Viking and Medieval York (cf. Kenward and Hall 1995). In the better preserved floor layers from Viking York, Oslo, and a number of Icelandic and Greenland sites palaeoecological investigations have shown that such floors were frequently covered with a mass of decomposing and fermenting vegetation, carrion and faecal matter and other detritus of life, thereby proving habitats for a wide range of invertebrates (Buckland et al. 1994). These floors may have played a further role, where living on permafrost or perennially frozen ground has a number of disadvantages–insulation could have been achieved by allowing the litter to build up (Buckland et al. 1994). More recently, several urban sites in Dublin have been investigated, including ninth to eleventh century deposits at Essex Street West (Reilly 2003). Here, fossil insect evidence helped to separate the use of the building between an earlier phase when it was used as an animal pen and a later phase

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when it was used for human occupation. The grain weevil, Sitophilus granarius L. was recovered from a pit from the site, a species which has been recovered from deposits elsewhere in Dublin, dated to the late thirteenth/early fourteenth century and from sixteenth century deposits in Limerick (Reilly 2003, 53). As Reilly highlights, it is not known when the species arrived in Ireland–in Britain, it was introduced during the Roman period and is typical of large-scale storage of grain–but its presence raises interesting questions concerning when the species arrived in Ireland. Was it a Viking import or did it arrive before this period during early trading? This work highlights some of the useful insights into early trading patterns which may not be evident amongst other archaeological data. Reilly (2003) also investigated thirteenth-century Anglo-Norman deposits at Back Lane in Dublin. Beetles recovered from house floors and structural timbers included large numbers of wood-dependant taxa, together with a number of rare and locally extinct taxa. Reilly (2003) suggests the species were probably transported into Dublin in structural timber or firewood and indicate that good quality woodland was still present within the catchment areas of the city during the Medieval period. Archaeological deposits of Medieval and Post-Medieval date at Newmarket (02E1692), in Dublin’s Liberties area, were recently excavated by Bill Frazer at Margaret Gowen and Co. Ltd., Dublin, and, amongst other specialist investigations, were studied for their plant, insect and parasite remains (Hall et al. 2004; 2005). The majority of the archaeological remains were from Phase III, dated to about 1673–1725 and Phase IV, dated from c. 1725–1830. A series of plots fronting onto Newmarket Street (formerly Skinners Alley) were revealed,

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with buildings to the front and yards to the back. Excavation showed that, as the old name for the street suggests, some of the inhabitants of Skinners Alley were involved in the processing of animal products. Newmarket itself was a twice weekly market selling farm products, including hides, wool, butter, and livestock; presumably some of the workers associated with the market were housed in the buildings excavated. During Phase IV some of the structures were subdivided and converted to tenements as the area descended into slums. It is from deposits associated with these Phases III and IV that the fossil insect remains were studied. Environmentally and historically speaking, this site covers a significant period, from which very few bioarchaeological investigations and especially insect assemblages are available for study (cf. Kenward 2004). The record from Newmarket is therefore especially important within this context. The features investigated were interpreted as fills of a range of different pits, including a dairy storage pit and other pits which were used at least at some stage of their life as privies. Some of the insect and plant assemblages were derived from faecal material, providing an insight into diets, but this was by no means the sole component of the fills, with considerable amounts of other material also having been deposited into the features. Such material included floor sweepings, straw and fuel waste, allowing the investigators an insight into living conditions. Much of the fauna suggests living circumstances which were not salubrious and bears remarkable similarities with other assemblages of Medieval date from Dublin (e.g. Reilly 2003) and Post-Medieval material from elsewhere (e.g. Jacques et al. 2004).

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Other highlights included the presence of two ‘pest’ alien species–the bedbug, Cimex lectularius L. and the oriental cockroach Blatta orientalis L.–both first fossil records for Ireland. Both records came from very specific deposits and the insects did not appear to have been widespread across the site. B. orientalis was recovered from a small pit lined with wooden staves from a bucket, sunk into the floor of a storage cellar. The pit was probably used for storage of dairy products, most likely butter. This was an important product at the time and was exported as far as the North American colonies and Caribbean (B. Frazer 2006, pers. comm.). The material probably dates to between 1711 and 1725 AD. From an entomological perspective its recovery is especially interesting, as modern entomologists have regarded the introduction of the cockroach as being recent–within the last few centuries–although its recovery in archaeological deposits from late fourth century AD Roman deposits in Lincoln (Dobney et al. 1998) indicates perhaps an earlier introduction. Two other records attest to its presence in recent centuries, with one possible specimen from mid-seventeenth century York (Hall et al. 1993) and confirmed identification of at least two individuals from late eighteenth to late nineteenth century deposits from Chester (Jacques et al. 2004). The records from Newmarket fall within a similar period. The bedbugs came from later deposits and are interesting as they only originated from privy pits located in an area known as Hass’ Gate; no other samples from the same phase included these ectoparasites (B. Frazer 2006 pers. comm.). The same samples also included internal parasites–whipworm (Ascaris sp.) and roundworm (Trichuris sp.). Contemporary historical accounts highlight the state of shocking overcrowding and dirt in this area which had degenerated into a slum area (B. Frazer 2006 pers. comm.). It is perhaps, therefore, no surprise 355

that the insect fauna indicates that living conditions in this area were far from healthy. Beyond the biogeographic and archaeological importance of these early records, the presence of both species in Post-Medieval Dublin highlight the effect of foreign trade on the development and movement of the synanthropic insect fauna. The Newmarket material provides a fascinating insight into urban life and it is without doubt an extremely important site as much for its archaeology as bioarchaeology. In contrast to these investigations from urban deposits, are those of an Early Christian rath site at Deer Park Farms, Co. Antrim (Kenward and Allison 1994; Allison et al. 1999). This site constitutes perhaps the largest and most thorough investigation using insects together with plant-macrofossil remains from an archaeological site in Ireland. This work was undertaken by the York Environmental Archaeology Unit. Extraordinary levels of preservation were present due to waterlogging of the site, but at a degree which is extremely rare on rural occupation sites. Allison et al. (1999, 3) consider the site to be of international significance in terms of providing a wide range of data about rural living conditions and resource exploitation. The insect fauna suggests that foul material was left exposed on the living surfaces of the rath, probably from animals. In the structures themselves, floors and bedding areas consisted of organic material, with plant litter on the floors and brushwood and turf in the bedding areas. Abundant human parasites were found associated with bedding structures, particularly the human louse, Pediaculus humanus L. and human flea, Pulex irritans L. A prominent feature of the site was the abundance of plant material which is likely to have been brought onto the site as raw material for

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construction or craft activities, including brushwood, bracken, heather, moss and turves. Seaweed also seems to have been brought onto the site, perhaps as manure or animal feed or for industrial purposes. Parasites of sheep, goats, cattle horses and pigs were present in some numbers, suggesting the presence of these animals living in the rath and/or their skins and wool for processing. Perhaps most remarkably, was the unexpected richness of a synanthrope fauna, particularly elements which are usually found in and around long-lived urban sites. This led the authors to suggest that this was an indication either of continuous occupation of the site over a considerable period of time, or that large quantities of material, along with its associated insect fauna, had been imported from existing settlements onto the site (Kenward 1997; Allison et al. 1999, 65). The results from Deer Park Farms suggests there is considerable potential in studying some of these rural settlement sites further and they have much to contribute towards our understanding of the development of such settlements and their wider context. Recent research associated with the Irish Lake Settlement Project of the Irish Discovery Programme at Lough Kinale has examined the environmental archaeological record associated with Ballywillin Crannog (O’Brien et al. 2005; Selby et al. 2005; Ruiz et al. 2006). The work included, amongst other approaches, the analysis of both fossil beetles and chironomids. The environmental record recovered covers the period from the construction of the crannog, c. cal. AD 640 and possibly up to the eighteenth century. A lake core was taken 10 cm from the outside of the palisade of the crannog and analysed, alongside other proxies, for its chironomid midge fauna. Although the crannog itself was not excavated, the work was able to highlight periods of more

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versus less intense activity and provided a good indication of the beginning of activity on the crannog. The results showed how levels of activity associated with the crannog caused increased eutrophication of the lake, especially from about cal. AD 1180, but that c. cal. AD 1330 activity became less intense, when the site may have been used for storage (Ruiz et al. 2006). Coleoptera found in plant macrofossil samples from the same core were also analysed. Although not especially numerous, the fossil beetle fauna showed an increase in diversity after cal. AD 620, as a result of deposition of plant and dung material close to the site, interpreted as being associated with crannog construction. After about cal. AD 900, the material included culture-favoured taxa typical of material associated with floor material and vegetable debris, including a common species associated with hay (Aglenus brunneus Gyll.) (O’Brien et al. 2005). This review of Irish urban and rural archaeological assemblages of Medieval and Post-Medieval data indicates the great value of examining fossil insect faunas associated with organic material from these deposits. However, although several investigations have focused on Dublin, very little is known of other Irish towns and cities and our understanding of what is happening in urban situations is extremely limited. Moreover, we know virtually nothing about the origins of the Irish urban fauna; when do the species which are typical of these environments become important in the archaeological record? What were the impacts of some of the major socio-political changes associated with the arrival of the Vikings and the Anglo-Normans, and with the Plantation? How far can these changes be identified in the fossil insect record and what changes did trading activities cause? Clearly, far more research is required, both of earlier periods

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(including prehistoric) and later, more recent periods, from a range of sites, of both urban and rural character.

Concluding Remarks This review has examined the discipline of fossil insects by looking at its use in a range of different applications and explaining some of the logistics behind collecting and analysing fossil insect samples. The Irish record is then reviewed, with regard to three important sub-areas of the discipline–climate change, Holocene environmental change and urban and rural archaeological sites of the Early Christian, Medieval and Post-Medieval periods. Work to date has been extremely useful palaeo-environmentally and archaeologically and thus the potential for further work is undoubted. Attention has been drawn to some of the areas for further investigation. By far the greatest issue at present is the need for a network of sites of different ages from a range of locations and contexts, both from archaeological and palaeoecological locations. We need to investigate sequences which cover the Holocene environmental history so that overall trends may be established, whilst also focusing on high resolution archaeological sites which will add detail to the broad picture. There is a particular need for further investigation of prehistoric settlement sites, which are largely untouched from this perspective. Finally, there is a real need for further practitioners to be trained in the discipline and establish active research groups, working on Irish material, whilst also highlighting the wider context of these records and their archaeological and palaeoenvironmental significance.

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Warren, M. S. and Key R. S. 1991. Woodlands: past, present and potential for insects, pp. 155–211 in Collins, N. M. and Thomas, J. A. (eds.), The Conservation of Insects and Their Habitats (15th Symposium of the Royal Entomological Society of London, 14–15 September 1989). London: Academic Press. Whitehead, P. F. 1992. Some notable records of Coleoptera. Entomologist’s Monthly Magazine 128, 184. Whitehouse, N. J. 1997. Insect faunas associated with Pinus sylvestris L. from the mid-Holocene of the Humberhead Levels, Yorkshire, U.K. Quaternary Proceedings 5, 293–303. Whitehouse, N. J. 1998. The Evolution of the Holocene Wetland Landscape of the Humberhead Levels from a Fossil Insect Perspective. Unpublished Ph.D. Thesis, University of Sheffield. Whitehouse N. J. 2004. Mire ontogeny, environmental and climate change inferred from fossil beetle successions from Hatfield Moors, eastern England. The Holocene 14, 79–93. Whitehouse, N. J. 2006. The Holocene British and Irish ancient woodland fossil beetle fauna: implications for woodland history, biodiversity and faunal colonisation. Quaternary Science Reviews 25, 1755–89. Wiederholm, T. (ed.) 1983. Chironomidae of the Holoartic region. Part 1, Larvae. Entomologica Scandinavia Supplimentum 19, 1–457. Wilkinson, B. J. 1984. Interpretation of past environments from sub-fossil Caddis Larvae, pp. 447–52 in Morse, J. C. (ed.), Proceedings of the 4th International Symposium on Trichoptera (Series Entomologicae 30). The Hague: W. Junk. 383

Acknowledgements The author would like especially to thank Prof. Paul Buckland for many useful discussions over the years on the advantages of a fossil insect approach. The author has also benefited from conversations with Stephen Brooks; Russell Coope; Mark Dinnin; Brian Evesham; Bill Frazer; Valerie Hall; Harry Kenward; Finbar McCormick; Eileen Murphy; John O’Neill; Jon Pilcher; Gill Plunkett; Pete Skidmore; David Smith; Eileen Reilly; Mark Robinson; Tessa Roper and Pat Wagner. I would also like to thank Ingelise Stuijs and Christina Fredrengen (Discovery Programme) for access to the Derragh samples and Bill Frazer (Margaret Gowen and Co. Ltd.) for access to samples from Newmarket Street and extremely useful contextual data, and to Jenny Watson for photos of chironomid head capsules. Libby Mulqueeny, Queens University Belfast, is thanked for cartographic assistance. The paper has benefited from the comments of Phil Barratt, whilst Harry Kenward is thanked for his reviewers’ comments.

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9 Environmental Archaeology in Ireland: A Personal and Archaeobotanical Perspective Michael Monk

Abstract Environmental Archaeology is of relatively recent currency, not developing into a loose coalition of specialist studies until the late 1970s when the Association for Environmental Archaeology was set up in Britain. As in Britain before the 1970s, in Ireland various formative pieces of research/ scholarship were carried out that would now be referred to as environmental archaeology–for example Frank Mitchell’s study of pollen sequences in association with artefacts and sites found in bogs during the early 1950s and the Goodland project in Co. Antrim, a joint study that involved Humphrey Case, Frank Mitchell, Bruce Proudfoot and Geoffrey Dimbleby. This paper will explore in brief the development of environmental archaeology in Ireland from its early beginnings in the twentieth century until the present. A particular focus will be on research of bioarchaeological material, especially the remains of plants. A further feature will be a survey of the development of environmental

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archaeology in third level education in Ireland. Reference will be made to the reasons for the initial slow take-off of environmental archaeology in Ireland, in comparison to the situation with Britain. A critique of present day cultural management practices and their consequence which mitigates against an organised approach to environmental archaeological work will also be provided. Some suggestions of the way forward will be made with particular reference to developments in the study of plant macrofossils.

Introduction The practice of Environmental Archaeology has been slow to take off in Ireland. This is not to say that there has been any shortage of research into past environments; rather that in Ireland work originating from strictly archaeological questions has been minimal. A particularly important area of palaeoenvironmental research has been palynology (see Plunkett, this volume). The science of pollen analysis was first introduced into Ireland from Scandinavia. There was, for example, the pioneering work of Gunnar Erdtman in the 1920s in the north-west and then, in the 1930s, Knud Jessen carried out the earliest work in the south-west and was responsible for teaching Frank Mitchell the analytical techniques (Erdtman 1928; Jessen 1949; Mitchell 1945; 1951; 1965). Over the years a substantial number of palynological researchers have come into Ireland to avail themselves of the deeply stratified sub-fossil bearing organic deposits in bogs and lakes. Local laboratories for such studies have been set up at Trinity College Dublin, Queen’s University Belfast and the Department of Botany at the National University of Ireland Galway (Palaeoecological Research Unit). The excellence achieved in palynology in

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Ireland has been recognised outside the island, while within the country this success was formative in the foundation of IQUA (Irish Quaternary Association) over 25 years ago. The outcome of nearly 80 years of pollen studies, and refinements of the technique, has been the improvement of resolution in the picture of regional vegetation change from the post-glacial until the near present (O’Connell and Molloy 2000). A key feature of vegetation change is the anthropogenic influence, especially after the establishment of farming. Over the last 30 years many palynological studies in Ireland have been undertaken close to, or in association with, archaeological sites–for example, Beaghmore and Ballynagilly, Co. Tyrone; Cashelkeelty, Co. Kerry; Loughnashade, Co. Armagh; the Céide Fields, Co. Mayo and Mooghaun, Co. Clare (Pilcher 1969; Pilcher and Smith 1979; Lynch 1981; Weir 1993; Molloy and O’Connell 1995; O’Connell et al. 2001). Those areas of environmental archaeology that we more usually associate with the sub-discipline–i.e. macro- and micro- plant remains and faunal remains (bioarchaeology) and soils and sediment studies associated with archaeological sites and landscapes (geoarchaeology)–have been far slower to develop. There have been a number of important developments, however, and it has become increasingly standard to put in place sampling strategies for the recovery of plant and faunal remains from excavations. At times, environmental archaeologists have also been attached to excavation projects specifically for the purposes of advising and undertaking sampling. The slow up-take of environmental archaeological research has resulted from a combination of factors amongst which has been the lack of emphasis on this aspect of the discipline in

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the education of archaeologists. It could equally be argued that it has been a consequence of a change of focus in archaeological theory. Environmental archaeology, as a coalition of different specialities, developed from the natural sciences and did so in Britain at a time when archaeology as a discipline was increasingly looking to, and drawing from, science for the purposes of gaining a clearer understanding of issues such as subsistence and environment. This was a time during which the theoretical paradigm of processual archaeology had grown out of systems theory as applied in ecology and geography. At the same time archaeology was increasingly being seen as a science itself (Johnson 1999, 22–5, 34–40, especially 35–7). These ideas had only limited impact in Ireland where, overall, the critical mass of archaeologists was small, especially by comparison to the frequency of extant archaeological sites and artefacts they had to curate and research. Archaeological training stressed description and typology, and interpretation was driven by cultural historical priorities as influenced by the ideas of diffusion (Herity and Eogan 1977; also Waddell 1978; 1998; Cooney 1995). Some archaeologists in the 1960s and early 1970s were, however, looking beyond Ireland to ideas and practices which were being undertaken elsewhere–not least Martin Jope at Queen’s University Belfast and M. J. O’Kelly in University College Cork. The former was a biochemist and a polymath and the latter was a civil engineer turned archaeologist. In Belfast, while there was no specific environmental archaeology course as such, a B.Sc. degree programme in archaeology developed. Close ties were also maintained with the Palaeoecology Centre which was set up as a result of an

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initiative by the archaeologically inclined palaeoecologist, Alan Smith, in conjunction with Martin Jope. In the south, from a very early stage in his fieldwork, M. J. O’Kelly called on advice from natural scientists. For example, in 1950 he enlisted the advice of soil scientists to explain the soil formation processes responsible for deposits discovered during his excavations at Moneen multiple cist cairn, Co. Cork (O’Kelly 1951). O’Kelly also networked with environmental archaeological scientists in Britain and on the continent. He invited scholars from the Instituut voor Prae-en Protohistorie (IPP), University of Amsterdam, to participate at his excavations at Newgrange (O’Kelly 1982). From this collaboration came Louise van Wijngaarden-Bakker’s important study of the Newgrange animal bone and Jan Peter Pals and Willy Groenman-van Waateringe’s work on the pollen and plant remains from the site (van Wijngaarden-Bakker 1974; 1986; Groenman-van Waateringe and Pals 1982). The link with IPP also resulted in two University College Cork (UCC) students studying at the Institute in Amsterdam. Anne Lynch studied palynology with Willy Groenman-van Waateringe, completing and publishing her Ph.D. on Man and Environment in S.W. Ireland in 1981 (Lynch 1981), while Finbar McCormick went to IPP to study with Louise van Wijngaarden-Bakker and to learn the craft of animal bone analysis. He completed his Masters degree in University College Cork in 1982 and later moved to Queen’s University Belfast where he completed his Ph.D. (McCormick 1982; 1987), and is now employed as a senior lecturer. The appointment of the current author in Cork overlapped with and enhanced the benefits of this initiative for the

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Department of Archaeology in University College Cork. Until relatively recently the two courses offered by the Department were the only undergraduate courses specifically described as covering environmental archaeology available to students based in Ireland. These courses have been taught within the context of a B.A. degree programme. The intention has been to provide students with a background in environmental archaeology, rather than to train environmental specialists. The current advanced option course, however, also includes practicals on plant and animal remains and has an assessed component. Over the 25 years that this programme has been running a number of students from Cork have gone on to undertake specialised Masters courses both in Ireland and elsewhere on various aspects of environmental archaeology. Increasing interest in the subject in Ireland as a whole in recent years has also resulted in students from other universities in Ireland similarly leaving the island to acquire specialist training within the broad field of environmental archaeology. Several of these former students from Cork and elsewhere have continued to work within the profession in Ireland and indeed this number has increased in the last few years with the rise of contract archaeology and a slow but sure increase in awareness amongst archaeologists, that the results of environmental archaeology can provide information of central importance to almost all aspects of archaeological field work. Of particular note, in the past, has been Siobhan Geraghty’s study of the plant remains from Fishamble Street, Woodquay, Dublin. With the enthusiasm and encouragement of Patrick Wallace, the site director at the time, and the support of the National Museum and then, later, Trinity College Dublin (as well as the Royal Irish Academy), Geraghty’s work came to

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fruition and was published in 1996 (Geraghty 1996). Shortly after the field component of the Woodquay project was completed, by Siobhan Geraghty, the Department of Archaeology in University College Cork became involved in archaeological field work in advance of the Cork to Dublin Gas pipeline (Cleary et al. 1987). This project provided an opportunity for several environmental archaeologists, including the present author, to initiate work on a number of diverse sites along the route. The Department’s active role in research and rescue excavations both within and outside the city during the early 1980s continued to provide opportunities for environmental archaeological studies. In many ways the results of this work has laid the foundation for much of the subsequent environmental archaeological research that took place during the urban archaeological campaigns of the later 1980s and early 1990s, and which has culminated in several publications, most notably the major report for the Waterford City excavations (Hurley et al. 1997; Tierney and Hannon 1997). The extent of environmental work has been patchy, influenced by the resourcing of the projects, concerns of the project managers, as well as the availability and differing interests of specialists. It is perhaps an indictment of the profession as a whole that in almost 25 years the importance of environmental work has not developed to the extent that it should have. Crucial research work has, however, been undertaken as part of the Discovery Programme and Wetland Unit campaigns in the south and the Palaeoecology Centre, Queen’s University Belfast, in the north of the island. Despite the important work undertaken by these organisations, there has not been the same support for environmental archaeology outside individual efforts within the universities. The

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problem, I believe, lies primarily in the education of archaeologists but also in the lack of consistent support from the institutions of the state in both the north and the south of the island, for which environmental archaeology has not been a priority. Environmental archaeological work has been undertaken on state funded projects (e.g. the excavations at Dublin Castle), but such work has not been consistently undertaken in the face of decreasing resources. State funded laboratories similar to those present in Britain and Holland, for example, or indeed regionally funded university-based environmental archaeologists are non-existent within an Irish context. The lack of consistent employment has up until recently, with the advent of commercial companies, dissuaded potential researchers from investing time in pursuing a career in environmental archaeology. Most of those with Masters’ qualifications in environmental archaeology have either left the subject entirely or have moved into other areas of the discipline. Most work for archaeologists, currently, is in developer-funded fieldwork where increasingly the prime concern has been to ‘stay on the right side of the developer’ who, under planning conditions pertaining to the development, is obliged to pay for the site’s ‘resolution’ before development can take place. This means that the developer is in the position to set the price, hence relatively expensive systematic environmental sampling and studies would not be seen as primary to the resolution of the stratigraphy and dating of the site. In consequence environmental archaeological work often comes low down on the budget for such sites, if it is present at all.

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The theoretical paradigm has also changed. The orthodoxy of processual archaeology was challenged in the 1980s and over the last 20 years the close association with the natural sciences has gone out of fashion. It now seems to be the view that the results of scientific analysis of material evidence of past peoples, including environmental remains, ranks lower ‘in value’ as against the discussion of the social meaning and aesthetics of cultural material remains (artefacts). This has generally slowed down the development of most scientific applications in archaeology, with the exception of DNA analysis and perhaps also areas such as stable isotope analysis of human remains (Ambrose 1993; Richards and Hedges 1999; Richards 2000). In Ireland where there has been minimal education in scientific methods in archaeology, and the more cultural historical inclined humanities approach has been to the fore, the embryonic growth of environmental archaeology remained stunted until recently. It is also a fact that there have been hardly any Irish archaeologists who embraced fully processual archaeological theory. This situation contrasts with the present where the new orthodoxy of post-processual (interpretative) archaeology has attracted the interest of a number of Irish-based archaeologists, including some who have been very supportive of environmental archaeological approaches (e.g. Fredengren 2002). This is easily explicable as the various post-processual theories, derived from European philosophies, fit better the mindset of arts educated archaeologists. There should therefore be no surprise that these ideas have been taken on with some enthusiasm by a number of Irish archaeologists, although this influence is still, at the time of writing, in its early stages and there have been few publications displaying an overt influence. Christina Fredengren’s (2002) pioneering book on crannógs has clearly been informed by 393

post-processual thinking as has Tadhg O’Keeffe’s (2004) book on round towers. Another example is Gabriel Cooney’s Landscapes of Neolithic Ireland, which significantly, draws heavily on results derived from environmental archaeology (Cooney 2000, see pages 34–45 for examples). Writing during the early twenty-first century it is clear that change has been taking place again and, as was the case during the early 1980s, this has been generated by an upsurge in fieldwork in response to the demands of modern developments threatening the archaeological resource. A younger generation of archaeologists, some of whom have gained their first degree in Irish archaeology and then acquired postgraduate training in science-based archaeology outside Ireland, have come back to pursue their careers here. These individuals are finding more regular long-term employment in environmental archaeology within commercial archaeological companies and to a lesser extent in the universities. For the first time in Ireland there is beginning to be a critical mass of consistently employed individuals willing to make a longer-term investment in this area of the discipline. As such, the future of environmental archaeological work in Ireland is brighter than it has ever been before. I feel, however, that it is still necessary to persuade our more culturally inclined colleagues of the fundamental contribution that the results of environmental archaeology can make, not least at the fieldwork level, where environmental studies can provide the context for all other material remains. At the interpretative level such research can provide the broader context for past human behaviour and especially in the interaction of past humans with their environment and with

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each other (and for both in more areas than the subsistence arena). This broader context has been highlighted by the late John Evans (2003), in a recent challenging book, where he argued that our perspective needs to change. His argument is that environmental archaeology is well positioned to provide the evidence, from both sites and landscapes, for what he feels is the main motive for all human endeavour–societal interaction. He sees this as a particularly strong motivating force, for example, in the adoption of the procedures and practices of farming (Evans 2003, 225–9). The lesson of the 1980s upsurge of environmental archaeology in Ireland that needs to be ‘taken on board’ this time is that the level of interest in environmental archaeology both within and outside the profession will not be maintained simply by it acting as a ‘service industry’ for the rest of the profession. It is necessary to produce and publish challenging work in thematic articles and books as well as accessible papers in general publications and local journals. Prompt and regular publications as part of collaborations with colleagues within the profession as a whole will, I feel, play a key role in sustaining the interest in the sub-discipline.

A Personal Reflection on Archaeobotanical Studies: Future Perspectives The legacy I inherited when I came to Ireland consisted of the work of Jessen and Helbaek and their seed imprint studies of the 1940s as well as Frank Mitchell’s individual studies of groups of macro-plant remains; some published and some not (Jessen and Helbaek 1944; Mitchell 1967, 101). I will always be indebted to Frank Mitchell for his generosity of advice and for passing over to me the results of his studies as well as consistently encouraging those colleagues willing to listen in

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regard to the importance of environmental studies in the Republic of Ireland. My intention in the first number of years in Cork was to develop a database of work that had been undertaken on plant remains and develop a framework for interpretation. A number of archaeological directors encouraged and facilitated this project and to them I owe a great deal for their support and access to their archaeological records. Most of this work, but not all, has been published, for example, in M. J. O’Kelly’s (1982) account of the excavations at Newgrange, Co. Meath, and in P. C. Woodman’s (1985) report on the excavations at Mount Sandel, Co. Londonderry. In the mid-1980s I published a paper entitled ‘Evidence from Macroscopic Plant Remains for Crop Husbandry in Prehistoric and Early Historic Ireland: A Review’ within the Journal of Irish Archaeology, the objective of which was to provide a framework for future research (Monk 1986). There were certainly various influences on my approach at that time, not least of these was a perceived need to demonstrate the importance of crop husbandry in Ireland’s past agricultural economy in the face of the pastorally dominated model then current. I also wanted to show how simple it was to get a basic idea of the pattern of crop husbandry in general, but at the same time point out potential biases within the data, especially when it was largely based on individual caches of charred remains. It was also an explicit decision to focus primarily on crop plant remains and not other remains from archaeological sites. This emphasis reflected my own research interests at the time but was also intended to draw the wider discipline’s attention towards the importance of studies on macro-plant remains as opposed to pollen, which had been the focus for environmental studies up until then.

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This paper has indeed provided the base line against which subsequent work has been compared and will continue to do so until those working on archaeobotany synthesise recent work to challenge that framework; this should be a priority. This author’s (1986) paper has also been referenced in general discussions of prehistoric and early subsistence economy and farming (Cooney and Grogan 1994; Waddell 1998). I and others have subsequently followed that work by focusing on the Early Medieval period in Ireland as a whole, and in Munster in particular (Monk 1991a; Monk et al. 1998). The way forward is, at one level, to bring together the disparate pieces of work that have been carried out under the auspices of developer-led archaeology over the last few years and discuss how our knowledge has moved on since the early/ mid-1980s. However, much of this more recent work is, for various reasons, inaccessible because it forms a part of a wider excavation project and is viewed by the directors of those projects as part of the site and in a sense their ‘property’. Under the excavation licensing system it is indeed their responsibility and the presentation of this work, as they see it, can only take its place within the context of the overall excavation report. Current licensing requirements in the Republic of Ireland require the excavator to lodge preliminary reports (some lodge completed reports, although seldom in publishable form) with the licensing authority. Once this has been undertaken, the pressure to bring the work to full publication is reduced and many excavation reports have remained in this limbo, relatively inaccessible, for many years. There is no straightforward way of even making an assessment of how many of these reports contain environmental archaeological work. In advance of publication the annual excavation summary accounts, edited by Isabel

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Bennett and published by Wordwell, provide an invaluable source of information. Without the free flow of such information research developments in environmental archaeology, as indeed in other areas, will remain restricted. There are signs that this situation is changing, however, and many archaeological companies/institutions have developed web-sites from which access can be gained to the results of a diverse range of archaeological projects. They are also increasingly happy to permit access to their work when contacted. The appointment of archaeologists by the National Roads Authority has also enabled easier access to information recovered during excavations in advance of road schemes. Brian Duffy, the chief archaeologist of the Heritage Service of the Department of Environment, Heritage and Local Government, has also announced that he is actively exploring the possibility of putting all archaeological reports, submitted to his office as part of the license requirement, on the internet. Ease of access to recent macro-plant remains’ reports would enable archaeobotanists to identify themes and questions that could develop from such new data. It would then be possible to concentrate on different periods, or on the transition phases between them to see, for instance, whether cultural changes are reflected in non-cultural material. Potential exists for such work for most past time periods not least the Bronze Age and Later Medieval periods. The former period is in fact the subject of Ph.D. research by Meriel McClatchie at the Institute of Archaeology, University College London, and I look forward to the results of her valuable study (see McClatchie, this volume). One theme raised by Geraghty in her study of the Later Early Medieval Fishamble Street, Dublin, remains was the extent to

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which hinterlands of urban centres could be traced and defined by archaeobotanical evidence from those centres (Geraghty 1996, 61–6). Tierney and Hannon (1997, 891–2) also raised this issue in their discussion of plant remains from the Waterford sites but were hampered, as in the Dublin study, by the absence of complementary evidence from contemporary rural sites. A recently completed Masters’ study by Abigail Brewer in the Department of Archaeology, University College Cork, however, has explored this theme further for Kilkenny and Limerick (Brewer 2001a; 2001b). Hinterland studies, if they are to reach their full potential require, by their nature, the integration of different data sources on the lines being developed by myself, Penny Johnston and other colleagues in the Novgorod project in Russia (Brisbane and Gaimster 2001; Monk and Johnston 2001). The study of archaeobotanical remains from the Later Medieval period would also benefit from exploration of documentary sources that make reference to the use and economic status of plants (McClatchie 2003). Such an integration of different data sources is essential. It is particularly relevant, as Wendy Smith (2001) has recently cogently argued, in a line of research that developed in archaeobotany nearly 20 years ago which focused on plant remains as an indicator of whether a site was primarily either producing or consuming agricultural produce (Hillman 1981; Jones 1985; see arguments by van der Veen 1992). This line of research has hardly developed within Ireland but holds a great deal of potential in all environmental studies for the Medieval period where data could be derived from a range sources. In 1998, together with John Tierney and Martha Hannon, I published the results of an assessment of plant remains from a

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series of near contemporary Early Medieval ringfort sites in Munster (Monk et al. 1998). The exercise demonstrated some similar themes but also indicated diversity in the crop plants present from site to site. Many of these sites, however, were occupied over long periods with very little build-up of stratigraphy, creating problems with accuracy in temporal resolution. This problem could be somewhat resolved if a systematic programme of thorough sampling was undertaken at a number of raths in a similar manner to the work undertaken at Deerpark Farms, Co. Antrim, during the 1980s (differential preservation within the mound accepted). Some preliminary results, obtained from a selection of samples derived from the site and studied for insect and macro-plant remains, were published in 1994 (Kenward and Allison 1994, 89–107). Despite the lack of temporal resolution in the Munster cases I do believe in the potential of regional studies of plant remains, either by period or through time, but that requires access to more data than is currently available. Such consistent systematic sampling strategies studies would, however, inevitably need to take into consideration variations in preservation and other taphonomic factors as well as contextual variability, most of which have only been properly considered in the last few years. Ever since the formative ethnographical studies by Hillman (1981) in Turkey and then, slightly later, Jones (1983; 1984) in Greece, archaeobotanists throughout Europe and the Middle East have been discussing the plant remains they have studied in terms of the stage, or stages, in crop processing that the remains had reached before entering the archaeological record and the contexts where they were found. The crop processing models developed from ethnographic studies have served us well and, while applied more easily in Eastern

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Europe and the Middle East, they have also been successfully used in northern Europe (e.g. van der Veen 1992). From ethnographical research it is clear that there are similarities in crop processing practices between the two regions but, because of bioclimatic differences and consequent differential cropping regimes, significant variations from the Greek and Turkish models are evident in temperate Europe. Research on these variations has been undertaken in Scotland (Smith 1994; 1996) and similar studies need to be produced for Ireland using extant sources for traditional farming practices. While crop-processing residues are occasionally found, they are for the most part uncommon. This is partly because few contexts contain undisturbed in situ remains and because most crops are more likely to become charred during the final stages of processing before domestic use. Having said this residues from, or associated with, corn-drying kilns have considerable potential to provide a ‘snap shot’ of crops either post-harvest pre-storage or post storage pre-milling, depending at what stage the remains became charred in the kiln (Monk 1987). More detailed inter-site comparisons also hold considerable potential in this area of study. Following on from this there is a need for more inter-contextual comparative studies, both on the same sites but between different sites. This would be particularly useful for similar context types, such as house walls and post-holes, as well as identifiable corn drying kilns. Broad contemporaneity of context type would, of course, be a variable that would need to be established in order to gain the most from the results of such work. Different periods offer up different context complexes and it is likely that the remains from them would vary. An understanding of the taphonomic

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processes affecting the infilling of features would be crucial before meaningful comparisons could be made of their content (Monk 1991b, 107–8; Monk in progress). Integrated research projects are becoming increasingly common in archaeology, as a survey of many journals will show, for example, Antiquity and Proceedings of the Prehistoric Society. In many cases these studies involve environmental and other scholars from archaeological science, for example, the archaeological and palaeoenvironmental investigations of the Upper Allen Valley in Dorset (French et al. 2003). An important study in the Irish context published recently is the Irish Wetland Unit’s publication of the excavation of the Mountdillon Bogs, Co. Longford (Raftery 1996). These projects had an important interdisciplinary palaeoenvironmental focus. It is very encouraging to note the existence of several similar projects in the final stages of production here in Ireland, where archaeobotanical studies will be even more to the fore than in either of these examples. Drawing together diverse results from different areas of scholarship can be very rewarding even though it may bring forth contrasting and sometimes divergent results that serve to challenge the interpretative basis of our research. I have had some experience of this via the Novgorod project and most recently the study of Early Medieval oatcake fragments recovered from the excavations at Lisleagh, Co. Cork. The study has involved histological and chemical analysis of the remains which have then been interpreted by reference to the documentary and ethnographic sources for the manufacture and consumption of oatcakes in conjunction with the archaeological and archaeobotanical context of the remains

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(McLaren et al. 2004). The potential value of histological and chemical studies combined with archaeobotanical research has been realised for some time (e.g. Hillman et al. 1993). The possibilities to be gained from such research, in conjunction with standard morphological studies of plant remains, have a great deal of potential within the Irish context. The attention of archaeobotanists has been biased towards the purely economic, utilitarian, interpretation of the plant remains they study. Even where macro-remains of so-called ‘wild’ flora are discovered all of us who work in the field tend to prioritise the possible functional economic use of those plants in our interpretations over other uses that may relate to the ways people viewed plants in the past or ritual practices which may have involved them. People in the past, as in the present, had perceived as well as real needs that required fulfilment from environmental resources in their locality, including plants. Although it may not be possible to understand the choice of certain plants for so called ritual practice, a basis for interpretation that has not been fully explored within Ireland is recent folk traditions. While the development of Christianity has probably caused the demise of many such traditions, others have persisted or were adopted by the Church. We in Ireland are fortunate to have a wealth of folklore upon which to draw and research is needed to help inform us of the interpretative possibilities in this arena. An example of how important folklore sources can be is Tony Lucas’ (1960) acclaimed study of furze/gorse (Ulex eurpaeus). Fairbairn (2000, 115, 120–1), has recently highlighted the possible non-utilitarian symbolic ideological significance of cereals amongst the first farmers in a paper on

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the evidence for Neolithic crops in Britain. Similarly, the status value of past crop plants requires exploration as indicated in the early documentary sources (see discussion, for example, of the high status value of wheat relative to other cereals in the Early Irish Medieval sources–Monk 1991a, 318–20; Kelly 1997, Sexton 1993; 1998). Due to the usual random and accidental nature of both preservation of crop plant remains and deposition in the contexts from which they are excavated we can seldom aspire to this level of interpretation. It is, nevertheless, important to appreciate the likely diversity of the place of plants in past human societies even where examples of epigraphic or documentary evidence to make a case for such an interpretation are lacking. It was noted above that hinterland studies around Medieval sites would be best served by an approach involving the integration of evidence from different data sources, including all areas of environmental archaeological research and particularly plant remains. This approach is applicable for most landscape/settlement projects and has been increasingly common practice elsewhere (Kemp et al. 1994; Mathews et al. 1994). An important opportunity has developed in this respect in the Discovery Programme’s Lake Settlement project for which, Ingelise Stuijs, an environmental archaeologist has recently been appointed. Similar research projects would do well to follow suit and indeed our government services should consider appointing such individuals to facilitate environmental archaeological requirements of excavation licenses, thereby, ensuring that it is part of the project design for all future work.

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Conclusion This essay has outlined the beginnings and early developments of environmental archaeology within Ireland from a personal perspective. Needless to say, there is a particular focus on archaeobotanical studies, particularly in the second part of the paper. I have followed this line in order to assess where I see openings for the development of the subject but we can only explore these successfully if these avenues of research are facilitated by the profession as a whole and the statutory bodies in particular. It has been noted that environmental archaeology, as opposed to palaeoecological studies, was slow to develop in Ireland, the former facilitated by the wealth of contexts with exceptional preservation of sequences of palaeoenvironmental material. It has been shown that there have been important developments in what would now be broadly called environmental archaeology. For the most part these developments were undertaken by individual researchers and owe a great deal to outside influences, many of which originally lay within the realm of palaeoecological studies. I have argued that the traditional focus of the archaeological profession, reinforced by the statutory bodies, on descriptive archaeology and culture history has been partly responsible for the slow adoption of environmental archaeology in Ireland. In addition, the arts educated backgrounds of most of our colleagues has meant that the post-processual paradigm has been more readily adopted by them in recent years than its processual predecessor. This has been unfortunate because the importance of the contribution of the natural sciences to archaeological questions was more easily realised within the framework of processual thinking than it has been since.

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However, as indeed was the case in Britain and on the continent in the 1970s, an upsurge in environmental archaeology has occurred at times when there has been a rise in rescue excavation leading to an increase in the recovery of environmental remains. This happened in Ireland during the early 1980s and has again been the case over the last ten years. The point was made that it is important to capitalise on these occasions and for environmental archaeologists to highlight the essential contribution that the sub-discipline can make to archaeology as a whole. Such a realisation did occur in the 1980s and a small group of like-minded people formed a loose discussion group under the umbrella ‘Man and Environment Work Group’. Several informal seminars were held by this group before the impetus behind it ran its course. Nevertheless, it did open up lines of communication between people. By comparison with the 1980s we have a distinct advantage at this time because we are now reaching a ‘critical mass’ of environmental archaeologists and archaeologists trained to appreciate the importance of this aspect of the discipline. As such, the future is much brighter than it has been to date. The mere fact that it has been possible to get other scholars working within Ireland to contribute to this volume is a testament of this. It is necessary, however, to evaluate the evidence we have obtained to date and there is still a problem with accessibility to new data that we need to address with some urgency in order to emphasise the value of existing studies. It is important to assess this new work and isolate emerging trends and issues; in the second part of this contribution I have made an attempt to do this for archaeobotany.

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McCormick, F. 1982. Man and Domesticated Mammals in Early Christian Ireland. Unpublished M.A. thesis, University College Cork (NUI). McCormick, F. 1987. Stockbreeding in Early Christian Ireland. Unpublished Ph.D. thesis, Queen’s University Belfast. McLaren, F. S., Monk., M. A. and Sexton, R. 2004. ‘Burning the biscuit’? evidence from Lisleagh excavations reveals new secrets twenty years on! Archaeology Ireland 18 (3), 18–20. Mitchell, G. F. 1945. The relative ages of archaeological objects recently found in bogs in Ireland. Proceedings of the Royal Irish Academy 50C, 1–19. Mitchell, G. F. 1951. Studies in Irish Quaternary deposits. Proceedings of the Royal Irish Academy 53B, 11–206. Mitchell, G. F. 1965. Littleton Bog, Tipperary: an Irish agricultural record. Journal of the Royal Society of Antiquaries of Ireland 95, 121–32. Mitchell, G. F. 1967. Appendix III, p. 101 in O’Kelly, M. J., Knockea, Co. Limerick, pp. 72–101 in Rynne, E (ed.), North Munster Studies: Essays in commemoration of Monsignor Michael Moloney. Limerick: Thomond Archaeological Society. Molloy, K. and O’Connell, M. 1995. Palaeoecological investigations towards the reconstruction of environmental and land-use changes during prehistory at Céide Fields, western Ireland. Probleme der Kustenforschung un sudlichen Nordseegebiet 23, 187–225.

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Monk, M. A. 1986. Evidence from macroscopic plant remains for crop husbandry in prehistoric and early historic Ireland: a review. Journal of Irish Archaeology 3, 31–6. Monk, M. A. 1987. Appendix II. Charred seed and plant remains, pp. 98–9 in Hurley M. F., Kilferagh, Co. Kilkenny, pp. 88–100 in Cleary, R. M., Hurley, M. F. and Twohig, E. T. (eds.), Archaeological Excavations on the Cork/Dublin Gas pipeline (1981–82) (Cork Archaeological Studies 1). Cork: Department of Archaeology, University College Cork. Monk, M. A. 1991a. The archaeobotanical evidence for field crop plants in early historic Ireland, pp. 315–28 in Renfrew. J. M. (ed.), New Light on Early Farming. Edinburgh: Edinburgh University Press. Monk, M. A. 1991b. The archaeobotanical work carried out for the M3 Project–A retrospective view, pp. 105–10 in Fasham, P. J. and Whinney, R. J. B. (eds.), Archaeology and the M3 (Monograph 7). Stroud: Hampshire Field Club, The Trust for Wessex Archaeology. Monk, M. A. in progress. Formation histories of infill features and the implications for environmental studies: lessons still to be learnt. Unpublished manuscript. Monk, M. and Johnston, P. 2001. Plants, people and environment: a report on the macro-plant remains within the deposits from Troitsky Site XI in Medieval Novgorod, pp. 113–7 in Brisbane, M., and Gaimster, D. (eds.), Novgorod: The Archaeology of a Russian Medieval City and its Hinterland (The British Museum Occasional Paper Number 141). London: The British Museum.

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Monk, M. A., Tierney, J. and Hannon, M. 1998. Archaeobotanical studies and Early Medieval Munster, pp. 65–75 in Monk, M. A. and Sheehan, J. (eds.), Early Medieval Munster: Archaeology, History and Society. Cork: Cork University Press. O’Connell. M. and Molloy, K. 2000. Farming and woodland dynamics in Ireland during the Neolithic. Biology and Environment. Proceedings of the Royal Irish Academy 101B, 99–128. O’Connell, M., Molloy, K. and McMahon, H. 2001. Reconstructing prehistoric farming activity and human impact at fine spatial resolution: palaeoecological investigations at Mooghaun, Co. Clare, Western Ireland, pp. 161–86 in P. Schauer (ed.), Beitrage zur Siedlungsarchäologie and zum Landschaftswandel. Regensburger Beiträge zur Prähistorischen Archäologie 7. O’Keeffe, T. 2004. Ireland’s Round Towers. Stroud: Tempus. O’Kelly, M. J. 1951. Some soil problems in archaeological excavation (with notes by S. Graham, B. Berks and F. J. North). Journal of Cork Archaeological and Historical Society 56, 29–44. O’Kelly, M. J. 1982. Newgrange: Archaeology, Art and Legend. London: Thames and Hudson. Pilcher, J. R. 1969. Archaeology, palaeoecology and C14 dating of the Beaghmore Stone circle site. Ulster Journal of Archaeology 32, 73–91. Pilcher, J. R. and Smith, A. G. 1979. Palaeoecological investigations at Ballynagilly, a Neolithic and Bronze Age

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settlement in County Tyrone, Northern Ireland. Philosophical Transactions of the Royal Society 286, 345–69. Raftery, B. 1996. Trackway Excavations in the Mountdillon Bogs, Co. Longford, 1985–1991 (Irish Archaeological Wetland Unit Transactions Volume 3). Dublin: Crannog Publication. Richards, M. P. 2000. Human consumption of plant foods in the British Neolithic: Direct evidence from bone stable isotopes, pp. 123–35 in Fairbairn, A. S. (ed.), Plants in Neolithic Britain and Beyond (Neolithic Studies Group Seminar Papers 5). Oxford: Oxbow. Richards, M. P. and Hedges, R. E. M. 1999. A Neolithic revolution? New evidence of diet in the British Neolithic. Antiquity 73, 891–97. Sexton, R. 1993. Cereals and Cereal Foodstuffs in the Early Historic Period. Unpublished M.A. thesis, University College Cork (NUI). Sexton, R. 1998. Porridges, gruels and breads: the cereal foodstuffs of Early Medieval Ireland, pp. 76–86 in Monk, M. A. and Sheehan, J. (eds.), Early Medieval Munster: Archaeology, History and Society. Cork: Cork University Press. Smith, H. 1994. Middening in the Outer Hebrides: An ethnoarchaeological Investigation. Unpublished Ph.D. thesis, University of Sheffield. Smith, H. 1996. An investigation of site formation processes on a traditional Hebridean farmstead using environmental and geoarchaeological techniques, pp. 195–206 in Gilbertson, D.

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D., Kent, M. and Gratton, J. (eds.), The Outer Hebrides: The last 14,000 years. Sheffield: Sheffield Academic Press. Smith, W. 2001. When method meets theory: the use and misuse of cereal producer/consumer models in archaeobotany, pp. 283–98 in Albarella, U. (ed.), Environmental Archaeology: Meaning and Purpose. The Netherlands: Klumer Academic Publishers. Tierney, J. and Hannon, M. 1997. Section 22: Plant remains, pp. 854–93 in Hurley, M. F., Scully, O. M. B. and McCutcheon, S. W. J. (eds.), Late Viking Age and Medieval Waterford: Excavations 1986–1992. Waterford: Waterford Corporation. Veen, van der M. 1991. Consumption or production? Agriculture in the Cambridgeshire Fens?, pp. 349–61 in Renfrew, J. M. (ed.), New Light on Early Farming: Recent Developments in Palaeoethnobotany. Edinburgh: Edinburgh University Press. Veen, van der M. 1992. Crop Husbandry Regimes: An archaeobotanical study of farming in Northern England 1000 BC to 500AD (Sheffield Archaeological Monographs 3). Sheffield: J. R. Collis Publications. Waddell, J. 1978. The invasion hypothesis in Irish prehistory. Antiquity 52, 121–8. Waddell, J. 1998. The Prehistoric Archaeology of Ireland. Galway: Galway University Press. Weir, D. A. 1993. Dark Ages and the pollen record. Emania 11, 21–30.

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Wijngaarden-Bakker, L. H. van 1974. The animal remains from the Beaker Settlement at Newgrange, Co. Meath: first report. Proceedings of the Royal Irish Academy 74C, 313–83. Wijngaarden-Bakker, L. H. van 1986. The animal remains from the Beaker settlement at Newgrange, Co. Meath: Final Report. Proceedings of the Royal Irish Academy 86C, 17–111. Woodman, P. C. 1985. Excavations at Mount Sandel 1973–1977. Belfast: HMSO.

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Acknowledgements I would like to thank Penny Johnston, Eileen Reilly and Judith Monk who read over and commented on earlier drafts of this text. My present and past students have been a source of inspiration to me. I would particularly like to acknowledge those who are now my colleagues, not least those whose published and unpublished research I have referenced here–Abigail Brewer, Martha Hannon, Penny Johnston, Meriel McClatchie, Finbar McCormick, Regina Sexton and John Tierney. Helen Smith also allowed me to reference her unpublished Ph.D. In addition I would like to thank Geraldine Murphy for her typing of the penultimate draft and the editors for their patience and advice. Two anonymous referees also offered editorial advice and made encouraging suggestions. However, responsibility for the content of this paper and the views expressed within rest with me.

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10 Wood and Charcoal Research in Ireland Ingelise Stuijts

Abstract This paper explores the value of wood and charcoal analysis to archaeological investigation. Following a description of former research, a short introduction into the methodology is given, together with a section on sampling strategies. Wood and charcoal are among the most frequent materials found during archaeological excavations. Wood was readily available in prehistoric times and hence was used for a range of purposes, from the building of structures to the crafting of domestic and artistic objects. Much of this wood ultimately ended up in domestic fires, leaving behind charcoal and ashes. Outside Ireland, the study of wood and charcoal has long been an integrated part of archaeological excavations. These studies have provided much insight into wood usage, woodland management and woodland changes over time. In Ireland, however, there have been few studies of large wood assemblages until recently. Investigations have concentrated mostly on species identification and wood working. Wooden artefacts, because of their archaeological value as objects, have tended to remain within the arena of the archaeologist rather than the wood specialist. Species identification has

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been the main goal of charcoal analysis, notably prior to radiocarbon dating. The last ten years has seen a growing interest in environmental archaeology, however, including wood and charcoal analysis. This has resulted in some very interesting studies. Three examples of wood and charcoal research in Ireland are presented; a wetland site, an urban site and research on material from marginal areas. Understanding wood usage goes beyond species identification, however. Future archaeological research in Ireland should incorporate more aspects of wood analysis, such as the examination of annual ring patterns, wood quality and insect damage. There is also a need for more research of vernacular sites. It is only through the full integration of environmental analysis and archaeological excavation that a deeper understanding of the life and environment of prehistoric people will be realised.

Introduction to the Study of Wood and Charcoal from Archaeological Sites The identification of wood is of great importance for archaeological research as wood was one of the most significant raw materials in prehistoric and early historical times. From a biological point of view, the anatomical study of wood may provide information on vegetation history, especially woodland history. However, trees not only grew in woodlands and bog margins, but also on field boundaries and in pasture woodland. These resources may have been exploited when found in the living environment of prehistoric people. Within a prehistoric community wood was used for a multitude of purposes, indoors as well as outdoors. It can be assumed that large timbers, used for the building of houses and farms, were obtained as close to a settlement as possible

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to avoid transport problems. The choice of a specific wood species depended on the quality, the strength, the speed and regularity of growth and the durability. The choice of wood also depended on the availability of a tree species. This could be physical (was the tree species growing locally?) or social (who owned the woodland?). In most cases oak was used for large constructions. Inside a settlement many objects were needed for normal household functions, from tools to kitchen utensils and furniture. These objects were all used for specific tasks and therefore required particular qualities from the wood from which they were made. The requirements varied from durability in dry and wet environments (ovens, hearths, fishing equipment, buckets and scoops), flexibility (axe handles, bows) and smoothness (bowls and spoons) to beauty (the use of burr wood for bowls). It is clear that this group could include a greater variety of wood species than structural timber, and this is reflected in the selection of certain wood species. Objects with the same function were usually made of the same or similar wood species. Firewood was usually gathered as close as possible to, or even within, a settlement. It is for this reason that the wood species found within charcoal hearths often provides information on the local vegetation directly surrounding settlements or activity areas. Other activities could also produce wood suitable for firing purposes. Local felling of trees for timber, for example, would leave a large proportion of the tree available for other purposes, such as firewood. If convenient, waste material such as chips or discarded building material or woodworking waste could also be used. The composition of charcoal assemblages might thus be

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influenced by other patterns of wood use. Charcoal studies can often give evidence for the kind of wood usage, through, for example, the presence of charred chips or twigs. It should be mentioned, however, that especially in historical times part of the local woodland may have been managed specifically to provide wood fuel or material for charcoal burning for metalworking. Oak and ash both produce good fuel, and are also excellent trees for timber. It is likely therefore, that ash and oak would have been encouraged in managed woodland.

History of Wood Identification and Analysis in Ireland Prior to the 1980s, there was limited research on wood and charcoal in Ireland. Mitchell (1986; 1989) analysed charcoal from Valencia Island. Other charcoal identifications occurred prior to radiocarbon dating of samples. In general, however, little attention was given to this research area, until the initiation of Barry Raftery’s excavations of bog trackways in Co. Longford in the late 1980s and the establishment of a student training course in wetland archaeology. This was coordinated by University College Dublin (UCD) and Exeter University and funded by the European Social Fund. From this group, some students emerged who have since been involved in wood and charcoal studies. These developments are exemplified by the work on Corlea Bog, Co. Longford (Raftery 1996), which can be considered one of the first major adventures in multi-proxy research in Ireland. This study incorporated the results of the impressive Iron Age trackway as well as detailed descriptions on wood working by Aidan O’Sullivan, wood identification by Aonghus Moloney, pollen work by Chris Caseldine and Jackie Hatton and peat stratigraphical research by Wil

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Casparie (Raftery 1996). This work was the inspiration for later work on, for example, Derryville Bog, Co. Tipperary, aspects of which are described below. A further development from Raftery’s work was the establishment in 1990 of the Irish Archaeological Wetland Unit (IAWU) as a joint initiative between UCD and the then Office of Public Works. The IAWU performed extensive research in the bogs of the Midlands of Ireland. Over the years, this group collected important information on the archaeology of bogs including wooden remains, and they have published the results on a regular basis (IAWU 1993a; 1993b; 1995). The IAWU ceased operations in 2005. Since the mid 1990s, there has been a growth in the number of projects carried out in wetlands and bogs. Besides institutions such as Queen’s University Belfast, where wetland research was already being carried out, other research institutions such as the Discovery Programme have developed an interest in wetland studies (e.g. the Lake Settlement Project). A number of other agencies and companies have developed wetland expertise and have undertaken significant projects, such as ADS, CRDS, Headland Archaeology and Margaret Gowen and Co. Ltd. amongst others. There is now a broader recognition of the importance of wetland research (see Plunkett and McDermott, this volume). Excavations in towns and cities have been carried out on a regular basis in advance of building activities and drainage works since the 1970s and 1980s. These produced large quantities of material including wood from the Viking, Norman and Medieval periods. In recent years many of these results have been published. These publications mostly concentrate on the wood identifications of artefacts. Examples

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include publications on Cork (Hurley and Tierney 1994; Hurley and Jones 1997), Dublin (Cross 1997; O’Sullivan and Deevy 2000) and Waterford (Hurley and McCutcheon 1997). Articles on aspects of woodworking and woodmanship were published by Wallace (1982) and O’Sullivan (1998; 2000). Other publications on wood and charcoal research include, amongst others, Hawthorne (1991) and O’Carroll (2001a; 2002b). McKeown (1994) worked on material from the Bronze Age mining site at Mount Gabriel, Co. Cork, and was also involved in work on Mesolithic material from Ferriter’s Cove, Co. Cork (1999). Her charcoal studies are among the few that used sampling of charcoal following a regular grid system. This grid system is used on the continent on a regular basis in archaeological excavations (Johansen et al. 2000; Carrion 2002; Dufraisse 2002). Due to the pressures of commercialisation, a significant amount of work that is currently undertaken by wood and charcoal specialists is not being published. This is a regrettable situation that is also developing on mainland Europe at the moment. There is a need for a centralised structure within Ireland where unpublished (and published) wood and charcoal data can be stored for future studies.

Methodology Microscopes are needed for the identification of wood and charcoal. Only wood from oak (Quercus) can be identified on site by trained archaeologists. Observations of growth patterns and the number of annual rings or age of the wood are usually made using stereo microscopes with low magnifications of up to x 40. For the identification of non-charred wood, thin slices are cut with razor blades and put onto a microscopic slide beneath a cover slip. For

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temporary slides, water is used as a medium, while for more permanent slides glycerine is used. Magnifications of x 100 to x 200 are generally sufficient for identification. For specific characteristics, magnifications of x 400 times are needed. Charcoal is broken along the three major axes (cross-section, radial and tangential) to expose a clear surface. After temporary mounting on clay, or in sand the surfaces are studied under indirect light. Magnifications of x 200 to x 400 times are normally required. There are some very good publications that describe the methodology of wood identification and include photographs of microscopic sections. The best known of these is Schweingruber’s (1978) Microscopic Wood Anatomy. In Ireland, relatively few wood species occur naturally in the prehistoric period when compared with assemblages from mainland Europe. In historic times, with imported wood species and plantations, a more diverse pattern can be expected.

Sampling Strategies Archaeological sites in themselves often determine the conditions of wood and charcoal survival. Most wood will be found in waterlogged conditions. Charcoal is also found in dry conditions, provided roots have not been able to penetrate too much. Wood can also be mineralised. This is often the case in river sediments, cesspits or lime-rich areas. When charcoal incorporates minerals such as calcium and iron it becomes almost stone-like in character. This occurs, for example, in waterlogged conditions at the bottom of troughs in fulachta fiadh and may make identification impossible. How much attention is given to the study of wood and charcoal depends to a large extent on the information

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archaeologists would like to receive from the material. In itself, the study can be very interesting from a biological point of view, but this aspect has not yet been fully explored in Ireland. Before a razor blade comes in contact with wooden remains, a license is required. For wood and charcoal identifications a ‘License to Alter’ should be obtained. For identifications leading to radiocarbon or dendrochronological dating a ‘License to Export’ may also be required. These licenses are obtained through the National Museum of Ireland. When wood and charcoal are sampled for dating purposes, the sampling area should be clean, as should the tools used to take samples. There should be no eating or smoking in the area. Chemicals should not be used. Identification should take place prior to conservation of artefacts because these techniques and chemicals permanently alter the structure of the wood. Based on wood research in Ireland over the last ten years, the following suggestions for wood and charcoal sampling can be made.

Wood Ideally all wood should be sampled. When large areas are excavated, this is not feasible. A discussion with the wood specialist is advisable when large excavations are planned to determine a budget and the formulation of a strategy. This consultation should occur prior to excavation. Several sampling methods are possible. One may choose to sample randomly one third of the exposed area. In this way, a

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good overview will be obtained. Otherwise, one may choose to sample a limited area including a few structures in detail (such as Viking wattle-work houses). For prehistoric sites with limited wood remains the preference may be to sample using a grid system, following a fixed pattern. This system is often used for shallow sites with unclear features, such as activity areas with flint and charcoal or an area with many pits. Small features, such as troughs from fulachta fiadh, should be sampled in their entirety. Ditches or moats can be bulk sampled to get maximum information on the local vegetation. Analysis of small environmental charcoal remains requires considerable work because of the small size and condition of the pieces, but can be very informative, especially when combined with the analysis of other macro-remains, such as beetles and molluscs. It is important to pack any sampled wood carefully. Generally, a plastic bag should contain a single wood item. In some cases more pieces, such as rods or sails, can be rolled in plastic with the number of pieces to be identified noted on the bag. Prehistoric wood is soft and fragile, and therefore should not be packed too tightly. This is to prevent the wood being broken. It is good practice to put some water inside the bag, or protect objects by embedding them in stone-free sediment (peat or clay). Storage should be cold and dark (such as in a refrigerator at 4 °C). The size of the wood samples may vary, depending on the questions to be answered. For the identification of brushwood, pieces with a width up to 6 cm and a hand length are sufficient. A length of 20 cm from larger timbers is advisable. Both can serve later for radiocarbon dating and/or dating through dendrochronological methods. Woodworking

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aspects are usually studied separately from the identification process. Identifications can be made using tiny slivers of wood, barely visible to the naked eye, and there is thus no excuse for not identifying artefacts.

Charcoal It is important to stress that charcoal should not be sampled by collecting individual pieces. The usual method is bulk sampling. Standard plastic buckets of 10 litres with lids are very suited for this purpose. For conventional radiocarbon dating, 5 gm are generally necessary, and this may require a large bag of charcoal (but see caveats of dating charcoal, as outlined in Barratt and Reimer, this volume). Charcoal research usually follows after the samples are examined for macrofossil remains. Sieving can be undertaken through wet sieving or flotation or a combination of both. This procedure can be performed on site after consultation with the macrofossil specialist. For charcoal, the larger sieves (2 or 4 mm) are used. The floating pieces and residues are usually dried on paper and stored in strong plastic bags. After macrofossil analysis the charcoal is forwarded to the charcoal specialist for identification. The sampling strategy depends on the questions to be addressed and on the budget. A single context may contain charcoal from a single event, and its composition may therefore be biased by one particular factor. If the objective is to gain information on which species were generally being used for fuel it is probably better to take bulk samples for charcoal from a wide range of contexts rather than just from one charcoal-rich hearth. The preferred method for charcoal

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research is sampling following a grid system, such as has been used for Palaeolithic and Mesolithic sites (Johansen et al. 2000; Stuijts 2006). For structures such as fulachta fiadh, bulk samples from a few areas such as the mound, the bottom of the trough and the top of the trough, are advisable.

Irish Case Studies The assemblages cited were studied by the author and are as yet unpublished with the exception of the Bronze Age aspects of Derryville Bog (Stuijts 2001; Stuijts and Gowen 2003).

Wetland site: Derryville Bog, Co. Tipperary Derryville Bog lies in Co. Tipperary, close to the county boundaries with Kilkenny and Laois. Between 1995 and 1998, Margaret Gowen and Co. Ltd. carried out extensive excavations in this area, on behalf of the Minorco-Lisheen mining company. The excavations in Derryville Bog, revealed horizons dating from the Late Neolithic to the Medieval period, and produced large quantities of wood, of which more than 8000 pieces were identified from 56 sites. Wood sampling occurred in close co-operation with the archaeologists, Sarah Cross, Cara Murray, John Ó Néill and Paul Stevens. Almost all of the wood assemblage was derived from structural wood. Most of the structures were not intended to cross the bog but instead to provide access to the marginal areas. Only three trackways were more substantial in length because these attempted to cross the bog, although they failed to do so. Most of the samples were derived from small access paths leading into the bog, platforms and fulachta fiadh. 428

A number of observations were made on the material from Derryville Bog. Apart from wood identification, the annual rings were counted. The tree ring counts served to establish how old the actual trees were rather than to produce the precise date of the samples. For dating purposes, dendrochronology should be used (see Brown and Baillie, this volume). In Derryville Bog it was noted whether the pieces were of fast growth or slow growth, and whether there were specific periods of extremely slow growth. These qualities may indicate the most likely origin of the wood, for example from bog margins or dry land. The condition of the wood, the degree of rot and the presence of roots in the samples was also noted. The quantity of roots indicates the degree to which the wood was exposed to oxygen. The wood identifications from Derryville Bog provided considerable information on the individual sites excavated. Thanks to the quantity of wood analysed, it was also possible to look at the overall trends in wood usage at Derryville Bog. These were compared with the results of wood analysis of un-worked (prehistoric) wood remains from Derryville Bog, sampled from trees preserved in peat and originally growing in situ in bog margins (Fig. 10.1), dated to the Bronze Age.

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Figure 10.1: Wood identifications of natural wood from peat deposits. More than 3500 identifications from 25 sites across Derryville Bog can be dated to the Bronze Age, based on radiocarbon dates and dendrochronological analysis (Gowen et al. 2005). However, when the wood identifications are grouped into the Early, Middle and Late periods (Figs. 10.2–10.4), some surprising results emerge. In the Early Bronze Age (Fig. 10.2), the general wood picture closely resembled the pattern shown by natural wood samples derived from peat deposits, with a dominance of alder (Alnus) and low values for hazel (Corylus). This period produced the only archaeological find of pine (Pinus sylvestris). The Early Bronze Age was the only period in which yew (Taxus) was represented in quantity. The Middle Bronze Age (Fig. 10.3), was characterised by a marked reduction in alder and an expansion of hazel. Yew had virtually disappeared. This period also saw conspicuously 430

low values for oak. Willow (Salix) was used much more frequently, which might indicate increased wetness. The Late Bronze Age (Fig. 10.4) witnessed a strong reduction in alder and further expansion of hazel accompanied by a noticeable rise in the use of oak. Quantities for ash (Fraxinus) declined. Although the quantity of natural wood samples was low compared with the archaeological wood remains, it is here assumed that the natural wood samples are representative of the woodland composition on the fringes of Derryville Bog in the past. It is suggested that the changes observed in wood usage over time may point to the impact of anthropogenic changes in the local landscape in the marginal areas surrounding Derryville Bog. The Early Bronze Age exploitation mirrors the natural environment where the marginal woodland was still fairly intact. There was, however, some human impact in the area based on the use of ash in the archaeological material. Ash is usually found in dry-land contexts in mixed woodland with oak and elm. An expansion of ash is noted in pollen diagrams from Ireland, especially after woodland cover is opened (Caseldine et al. 1996). It should be mentioned, however, that ash, with its colonising abilities, often expands into bog margins, especially when enough nutrients are available. It has been suggested that ash may have formed an integral part of the fen vegetation (Koot and Bakels 2002). It is thus possible that during the Early Bronze Age ash was collected from the fen margins.

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Figure 10.2: Early Bronze Age wood identifications (N=601).

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Figure 10.3: Middle Bronze Age wood identifications (N=2265).

Figure 10.4: Late Bronze Age wood identifications (N=809). Based on the wood identifications, the usage of the local landscape appears to have changed in the Middle Bronze Age. During this period, part of the marginal woodland disappeared, resulting in open areas for easier access or pasturage. This is particularly witnessed by the increased use of hazel and a reduction in alder. Also, an increase in the number of fulachta fiadh suggests that prehistoric people were living close to the margins of the bog. There are strong indications of management in the form of coppicing by the Late Bronze Age, shown not only by the high values for hazel but also the age distribution and growth pattern of this wood species. The bog margins appear to have

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been cleared to a large extent, as evidenced by the low values for alder, and there may have been direct access to the bog. The increased usage of oak is notable. It remains to be seen to what extent this feature is restricted to Derryville Bog and whether other Late Bronze Age sites will show a similar pattern.

Figure 10.5: Charcoal from fulachta fiadh total weight. Marginal Areas: Charcoal from Fulachta Fiadh These are one of the commonest monuments in Ireland and many are excavated every year. Their function was to capture clean water that was subsequently heated. Their purpose may have been varied as suggested by the range of structures found associated with them. Fulachta fiadh are usually poor sites for the recovery of environmental material, apart from some exceptions, as discussed below. Usually neither pollen nor seeds are associated with them and macro-remains often

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post-date the sites’ use. Some hazelnuts and leaves have occasionally been found. Remnants of the trough may be present and these are usually made from wood, roundwood, posts, planks or rods. Charcoal is usually found in all fulachta fiadh and is one of the defining characteristics of this site type (Brindley et al. 1989/90, 25). In some troughs bone fragments have been found, while other finds include fragments of grinding stones and some flints. Generally few artefacts are associated with these features. Because fuel tended to be collected as close as possible to the firing spot, these monuments lend themselves well to charcoal studies of the immediate landscape surrounding the sites. Archaeologists working for Margaret Gowen and Co. Ltd. (Edmond O’Donovan, Ian Doyle, John Ó Néill, Red Tobin and Paul Stevens) provided most of the material that has been analysed so far by the author. Steven Reed, working for Judith Carroll and Co., excavated Cootehill in Co. Cavan, while Fiona Reilly, for Valerie J. Keeley Ltd., directed the excavation of the site at Carrigoran in Co. Clare. Charcoal from 25 fulachta fiadh has been analysed by the author, most of which has been dated. Most samples were from Counties Dublin, Tipperary, Kilkenny and Cork. The results show a great difference between the counties and offer considerable potential for further study. It can be said that a variety of wood species occurred in most fulachta fiadh. Figure 10.5 shows collated results of the charcoal analyses to date. Although a wide range of species has been identified, only a limited number of wood species are of significance. These include hazel, alder, oak, ash, apple type (Pomoideae) and to a lesser extent yew and willow. Many charcoal fragments were parts of twigs or small branches of poor quality; it can therefore be assumed that most material was locally gathered.

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The charcoal assemblage of the fulacht fiadh sites includes some species that are not represented in wood assemblage from Derryville Bog such as gorse (Ulex), ling (Calluna), traveller’s joy (Clematis), spindle-tree (Euonymus) and ivy (Hedera). These can be explained by the fact that twiggy brush-woods such as gorse and ling do not lend themselves well for building purposes for trackways in bogs and therefore were not selected. In this sense, the wood results from Derryville Bog show a bias towards wood species growing in marginal woodlands surrounding the bog with diameters larger than 1–2 cm. and smaller shrub species are under-represented. In contrast, the charcoal assemblages from fulachta fiadh very often reflect the preference for smaller-sized brush-woods.

Urban Sites: West End, Dublin Linzi Simpson, on behalf of Margaret Gowen and Co. Ltd., carried out extensive excavations in West End, Dublin, in the 1990s. The site was in use over a long period of time, and included houses dating to the Viking Age, but also more recent structures, such as plank-lined pits from Anglo-Norman contexts (Simpson 1999). Most of the wooden remains examined derived from wattle houses, cattle pens, pathways and floors associated with the period roughly from 860–1100 cal. AD, based on radiocarbon dates and archaeological artefacts. A large part of the structural wood was of hazel, and the general wood usage pattern, based on the analysis of wood from houses, was unremarkable (Fig. 10.6). Apart from hazel, the only other 436

significant wood species were alder, ash and willow. Oak was almost completely absent. In contrast, a much more dynamic picture emerged when the wooden artefacts were examined. Approximately 200 objects were available for wood identification. Dowels hammered into artefacts, bucket staves and worked planks were also included in the analyses of artefact composition (Fig. 10.7). The proportion of artefacts made of oak was higher when compared with the structural wood results. Considering that oak is usually one of the three most commonly used wood species in urban sites on the Continent (along with alder and ash), this is a fact that deserves further study. Equally important amongst the artefacts was the use of yew. The occurrence of some non-indigenous wood species, such as spruce (Picea), silver fir (Abies), box (Buxus), possibly juniper (Juniperus) and Scots pine is also noteworthy. These clearly represent imported objects or wood. It is worth pointing out that the imported artefacts might not have been identified as such without the species information. In conclusion, it can be said that although the analysis of the wood used in construction indicated the usage of local wood species and a scarcity of oak, the identification of the wooden artefacts suggested a more complex picture. Perhaps oak was reserved for specific purposes or people or was scarce and therefore especially prized. The use of oak may have been regulated by those who owned the rights to the woodland, and especially the rights to the use of larger timber from such woodland. The artefact analysis points to the presence of trade goods, re-used timbers from overseas and wood working in situ (wood turning). The artefacts made of yew and oak possibly reflect transport to Dublin of these wood

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species from the local woodlands rather than imports, in either raw form or as finished articles. It should be noted that not all of the objects were dated to the Viking Age, and that some came from later periods.

Figure 10.6: Identifications of structural wood from West End, Dublin.

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Figure 10.7: Identifications of the wood derived from artefacts from West End, Dublin.

Conclusions Wood and charcoal research in Ireland has increased in recent years, with a consequent increase in the number of publications. The examples presented here have concentrated on species identification to highlight the possibilities of this kind of research. It should be stressed that other aspects of wood research such as annual ring counts, measurements, abnormalities in growth patterns etc. offer even greater potential for the interpretation of a wood assemblage. Although the number of native wood species in Ireland is relatively low, this does not diminish their potential for further research. The large stretches of bog, for example, preserve a vast wealth in wood remains containing information on the environments of prehistoric peoples. When exposed, this material should be collected and investigated 439

not only for identification purposes, but also for information on woodland management. The level of preservation of wooden remains can also be informative, indicating a horizontal or vertical position in the ground, the length of exposure on the bog surface and usage or the degree of wetness on the mire. Species identification and ring counts can be useful for identifying suitable samples for dendrochronological analysis. Although dendrochronology tends to rely on oak dating, it is possible to use the same method for other wood species, such as ash or pine. This may be especially fruitful when establishing a relative internal chronology of a given site. There is a clear need for a landscape approach, where the wood assemblage is used to reconstruct the local woodland composition. To achieve this, large quantities of wood are required and bogs in Ireland lend themselves well to this type of study. The future for landscape studies may lie in a multi-proxy approach, in which a series of environmental disciplines, each with its own particular strengths, produces independent data sets. These studies may include pollen analysis, plant and seed studies, dendrochronology, beetles and molluscs. As shown in this article, wood and charcoal studies would certainly benefit this type of research. From an urban point of view, much research remains to be undertaken. The focus has been on large structural timbers at the expense of brushwood assemblages. The latter lend themselves well to the reconstruction of local environments. To achieve this, remains from well-dated contexts such as moats, ditches and wells should be bulk sampled and fully investigated. Wells in particular are suitable for such studies

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as they also provide complementary plant and insect macrofossil assemblages. It has also become clear that there is need for further work on imported wooden artefacts. It is curious that on the one hand, Ireland seems to have been very outward looking, yet on the other hand, only a limited number of imported wooden objects have yet been identified. The wooden vessels made of fir and spruce, which were in widespread use on the Continent over a prolonged period and which so far have not been identified in Ireland, demonstrate this.

References Brindley, A. L., Lanting, J. N. and Mook, W. G. 1989/90. Radiocarbon dates from Irish fulachta fiadh and other burnt mounds. Journal of Irish Archaeology 5, 25–33. Carrion, Y. 2002. Charcoal analysis at La Falaguerra rockshelter (Alcoi, Alacant, Spain) from the Mesolithic to the Bronze Age: landscape and the use of plant resources, pp. 103–8, in Thiébault, S. (ed.), Charcoal Analysis. Methodological Approaches, Palaeoecological Results and Wood Uses (BAR International Series 1063). Oxford: Archaeopress. Caseldine, C. J. and Hatton, J. M. 1996. Early land clearance and wooden trackway construction in the third and fourth millennia BC at Corlea, Co. Longford. Proceedings of the Royal Irish Academy 95 B, 1–9. Cross, S. 1997. Wooden objects, pp. 159–62 in Walsh, C., Archaeological Excavations at Patrick, Nicholas and Winetavern Streets, Dublin. Dingle: Brandon Book Publishers.

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Dufraisse, A. 2002. Charcoal analysis in a lake dwelling site (Chalain 19, Jura, France): a sampling model for Neolithic lacustrine contexts, pp. 17–24 in Thiébault, S. (ed.), Charcoal Analysis. Methodological Approaches, Palaeoecological Results and Wood Uses (BAR International Series 1063). Oxford: Archaeopress. Gowen, M., Ó Néill, J. J. and Phillips, M. (eds.) 2005. The Lisheen Mine Archaeological Project 1996–8. Bray: Wordwell. Hawthorne, M. 1991. A preliminary analysis of wood remains from Haughey’s Fort. Emania 8, 34–8. Hurley, M. F. and Jones, P. 1997. Wooden artefacts, pp. 274–310 in Cleary, R. M.; Hurley, M. F. and Shee Twohig, R. (eds.), Skiddy’s Castle and Christ Church, Cork Excavations 1974–77 by D. C. Twohig. Cork: Cork Corporation. Hurley, M. F. and McCutcheon, S. W. J. 1997. Wooden artefacts, pp. 553–636 in Hurley, M.; Scully, O. and McCutcheon, S. (eds.), Late Viking Age and Medieval Waterford, Excavations 1980–1992. Waterford: Waterford Corporation. Hurley, M. F. and Tierney, J. 1997. Wooden artefacts, pp. 136–41 in Hurley, M. F. and Cleary, R. M. (eds.), Excavations at the North Gate, Cork, 1994. Cork: Cork Corporation. Irish Archaeology Wetland Unit, 1993a. Survey of the Raised Bogs of County Longford (Transactions of the Irish Archaeology Wetland Unit 1). Dublin: Crannóg Publications.

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Irish Archaeology Wetland Unit, 1993b. Excavations at Clonfinlough, County Offaly (Transactions of the Irish Archaeology Wetland Unit 2). Dublin: Crannóg Publications. Irish Archaeology Wetland Unit, 1995. Blackwater Survey and Excavations, Artefact Deterioration in Peatlands, Lough More, Co. Mayo (Transactions of the Irish Archaeology Wetland Unit 4). Dublin: Crannóg Publications. Johansen, L., Lanting, J. H., Lauwerier, R. C. G. M., Niekus, M. J. L. Th., Stapert, D. and Stuijts, I.-L. M. 2000. De Federmesser-vindplaats bij Doetinchem (Gld.): natuurwetenschappelijk ondersoek. Paleo-aktueel 11, 9–14. Koot, C. W. and Bakels, C. C. 2002. Wood resources and their exploitation during the Iron Age occupation of the Fens of Midden- Delfland, the Netherlands. Journal of Wetland Archaeology 2, 1–23. McKeown, S. 1994. Wood remains, pp. 265–81 in O’Brien, W., Mount Gabriel: Bronze Age Mining in Ireland. Galway: Galway University Press. McKeown, S. 1999. Charred wood, pp. 213–7 in Woodman, P.; Andersen E. and Finlay, N. Excavations at Ferriter’s Cove, 1983–95: Last Foragers, First Farmers in the Dingle Peninsula. Bray: Wordwell. Mitchell, G. F. 1986. The Shell Guide to Reading the Irish Landscape. Dublin: Country House. Mitchell, G. F. 1989. Man and Environment on Valencia Island. Dublin: Royal Irish Academy. O’Carroll, E. 2001a. Analysis of archaeological wood found in Irish bogs, pp. 27–35 in Raftery B. and Hickey J. (eds.),

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Recent Developments in Wetland Research (Seandálaíocht: Monograph 2, Department of Archaeology, University College Dublin and WARP Occasional Paper 14). Dublin: Department of Archaeology, University College Dublin. O’Carroll, E. 2001b. The Archaeology of Lemanaghan. The Story of an Irish Bog. Bray: Wordwell. O’Sullivan, A. 1998. Woodmanship and the supply of underwood and timber to Anglo-Norman Dublin, pp. 59–71 in Manning, C. (ed.) Dublin and Beyond the Pale. Bray: Wordwell. O’Sullivan, A. 2000. The wooden waterfronts: a study of their construction, carpentry and use of trees and woodlands, pp. 62–92 in Halpin, A., The Port of Medieval Dublin. Dublin: Four Courts Press. O’Sullivan, A. and Deevy, M. 2000. Wooden Artefacts, pp. 162–7 in Halpin, A., The Port of Medieval Dublin. Dublin: Four Courts Press. Raftery, B. 1996. Trackway Excavations in the Mountdillon Bogs, Co. Longford, 1985–1991 (Transactions of the Irish Archaeological Wetland Unit 3). Dublin: Crannóg Publications. Schweingruber, F. H. 1978. Microscopic Wood Anatomy. Birmensdorf: Swiss Federal Institute of Forestry Research. Simpson, L. 1999. Director’s Findings–Temple Bar West. Dublin: Temple Bar Properties. Stuijts, I. 2001. Bronze Age landscape changes in the Midlands of Ireland, pp. 527–37 in Metz, W. H., van Beek, B. L. and Steegstra, H. (eds.), PATINA, Essays Presented to J. J.

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Butler on the Occasion of His 80th Birthday. Drachten: Metz, Van Beek and Steegstra private publishing. Stuijts, I. 2006. Charcoal sampling sites and procedures: practical themes from Ireland, pp. 25–33 in Dufraisse, A. (ed.), Charcoal Analysis: New Analytical Tools and Methods for Archaeology. Papers from the Table-Ronde held in Basel 2004 (BAR International Series 1483). Oxford: Archaeopress. Stuijts, I. and Gowen, M. 2003. Trackways and Fulachta fiadh in rural Ireland: wood results from Derryville Bog, County Tipperary, Ireland, pp. 13–24 in Bauerochse, A. and Haßmann, H. (eds.), Peatlands; Proceedings of the Peatland Conference 2002 in Hannover, Germany. Rahden/Westf: Verlag Marie Leidorf. Wallace, P. F. 1982. Carpentry in Ireland AD 900–1300: the Wood Quay evidence, pp. 263–99 in McGrail, S. (ed.), Woodworking Techniques Before AD 150 (BAR British Series 129). Oxford: British Archaeological Reports.

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Acknowledgements The author would like to thank the support of the Discovery Programme. Special thanks go to Conor McDermott (UCD), Dr. Annaba Kilfeather and the anonymous referee for improving the English text and valuable comments. Much appreciation goes to all the archaeologists who extracted the wood and charcoal from their sites and allowed the author to use the results for this publication. Here, the author is especially grateful to Margaret Gowen and Linzi Simpson.

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11 The Study of Non-Wood Plant Macro-remains: Investigating Past Societies and Landscapes Meriel McClatchie

Abstract This paper provides an Irish perspective to approaches and techniques in the retrieval, identification and interpretation of non-wood plant macro-remains from archaeological deposits. The range of information that can be gleaned from the study of plant macro-remains preserved through various mechanisms is explored. The benefits of integration with a range of other archaeological and environmental approaches are also considered. Development of the study of plant macro-remains in Ireland is reviewed. A guide towards the selection and processing of samples is presented, and methods relating to the extraction and identification of plant macro-remains are examined. A case study is then presented, demonstrating an approach in the interpretation of plant macro-remains by assessing the significance of material from prehistoric and Early Medieval deposits at Kerlogue, Co. Wexford. The paper concludes by considering future opportunities for the study of plant macro-remains in Ireland.

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Why Study Plant Macro-remains? A General Introduction Archaeobotany is the study of past societies and environments through the analysis of preserved plant remains, the plant remains usually being derived from archaeological deposits. The terms ‘archaeobotany’ and ‘palaeoethnobotany’ are both used to refer to the study of preserved plant material deriving from archaeological deposits. The term ‘palaeobotany’ does not encompass cultural interactions and is therefore unsuitable in an archaeological context, but the term ‘palaeoethnobotany’ is also inappropriate, as it emphasises human-plant interactions, while paying less attention to evidence for past environments. The term ‘archaeobotany’ will therefore be used throughout this paper. Archaeobotany demands expertise in both archaeology and botany. The archaeologist must learn about vegetation systems, plant taxonomy and anatomy, and must also have the relevant skills necessary for the recovery and identification of preserved material. The botanist must learn how to communicate effectively with archaeologists, the ways in which preserved material might be interpreted in an archaeological context, and also how to deal with fragmentary material and the partial record that archaeology will almost always provide.

Range of study A broad range of preserved plant remains is studied in archaeobotany, including seeds and fruits of higher plants, vegetative components of plants, parenchymatous tissues (underground storage organs of plants, such as roots and tubers), fibres, phytoliths, wood, pollen and starch grains, as

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well as lower plants, such as mosses and fungi. Most archaeobotanical workers focus their analyses on a small range of these various types of remains. The term ‘plant micro-remains’ refers to material that requires high-power magnification for observation and identification. Phytoliths are an example of micro-remains, ranging in length from 0.005 to 0.25 mm. This paper will focus on non-wood plant macro-remains. The term ‘plant macro-remains’ usually refers to plant structures that can be seen with the naked eye when extracted from archaeological deposits, but these remains are often not discernible during excavation. Plant macro-remains can usually be identified using low-power magnification, in the range of x 6 to x 40. The use of other microscopy techniques, such as scanning electron microscopy, may also be required, for example in the determination of cell patterns. Seed, fruit and nut remains represent the most commonly encountered non-wood plant macro-remains, and delicate chaff from arable crops is also frequently recovered. Cereal bran is part of the periderm of the grass caryopsis and can be preserved in certain conditions (Dickson 1987). Other plant components, such as leaves, bud-scales and thorns can also be preserved, and criteria for the identification of vegetative parenchyma have been determined in recent years (Hather 1993; 2000).

Deposition and Preservation of Plant Macro-remains Plant macro-remains can be deposited by human and animal action, or can be naturally incorporated in deposits, for example through silting and other methods of accumulation. Processes involved in the use, discard and deposition of

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material may greatly affect the potential for material to survive. Site-formation processes (taphonomic factors that include burial and post-burial processes and events) are also often significant (Gifford 1981; Huntley and Stallibrass 2000). A range of preservation methods–including charring, waterlogging, desiccation and mineralisation–will result in the survival of plant remains, and archaeological deposits can sometimes incorporate remains preserved by a combination of such methods (Boardman 2000; Holden 2000; Smith 2003). On many occupation sites in Ireland–particularly on well-drained soils–plant macro-remains are most commonly preserved as a result of charring. Charring (also referred to as carbonisation) occurs during a burning event when the supply of oxygen is insufficient for combustion to occur and the plant material is transformed into a chemically-inert carbon. Preservation is less likely when plant material is incorporated into the oxidising conditions of the open flame, resulting in its combustion and reduction to mineral ash, perhaps leaving traces of silica skeletons (Robinson and Straker 1991). Various components of plants can be subject to differential preservation when charred; cereal chaff is, for example, less likely to be preserved than denser, more robust cereal grains (Wilson 1984; Boardman and Jones 1990). Charred plant macro-remains are generally stable–being carbon-rich, they are resistant to chemical and biological breakdown. Remains can, however, be degraded by mechanical damage, such as post-deposition trampling and careless handling during recovery, as well as by a continuous cycle of wetting and drying and/or freezing and thawing of deposits. A range of plants in the original thatch of Medieval and Post-Medieval structures can also be preserved through smoke-blackening (Letts 1999).

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Charring can result from a range of activities, which may be either purposeful or incidental. Incidental burning may have occurred when cereals were dried after a damp harvest, prior to storage, during the separation of grains from chaff or in advance of malting (Hillman 1981; 1984a; 1984b; 1985; Jones 1984; Dineley 2004). Incidental charring of plant materials can also result from episodes such as catastrophic fires, for example in the burning of grain stores (Jones et al. 1986) or house and roofing structures. Purposeful burning may result from activities such as military actions, for example in the burning of an enemy’s arable crops (Calendar of State Papers Ireland 1600, 67). Purposeful burning may also result from the burning of stubble in fields and other traditional agricultural techniques such as graddaning (Fenton 1976, 94–5), which is the purposeful burning of cereal ears off their stalks in the field to facilitate less threshing of the crop. Repeated use of grain-storage pits may require occasional burning of the pits for sterilisation, which may result in the charring of material lining the pits. The burning of domestic waste, including floor sweepings and food debris such as nutshells, as fuel or to reduce its mass may also lead to the preservation of remains. Plants that are more likely to come into contact with fire during food processing, preparation and discard activities, such as cereals, pulses, arable weeds and nuts, will therefore often dominate assemblages of charred plant macro-remains. Another potential source for charred seeds is from burnt dung. While the use of dung as fuel has been considered a likely source for semi-arid environments of the Near East (Miller 1984; 1996; 1997; Miller and Smart 1984; Charles 1998), it may be less significant in north-western Europe, due to climatic constraints on drying dung and increased availability of wood fuels (Hillman et al. 1997; Fuller et al. in press). 451

Another method of preservation–evident especially in Irish urban deposits–occurs when material is incorporated into anoxic conditions, whereby air is excluded from deposits, and plant tissues do not break down and become degraded. Anoxic preservation is also referred to as waterlogging and anaerobic preservation, and this mechanism can occur in areas with a high water table, in deposits of a very organic nature, and occasionally when deposits are well-sealed, for example by a heavy clay (Weir and Conway 1988; Geraghty 1996; Tierney and Hannon 1997; McClatchie 2003). Anoxic preservation is also often encountered in natural deposits from environments such as peatlands, rivers and lakes. Mineral replacement typically occurs in cess pits and deposits where there is a high concentration of calcium salts, principally phosphates, thus rendering the plant remains resistant to decay (Green 1979; McCobb et al. 2001). Desiccation is a mechanism of preservation rarely seen in Irish material, but commonly encountered in arid regions, and the range and quality of remains preserved can be superior to that encountered with waterlogged preservation (Van der Veen 1998; Smith 2003). As well as actual plant macro-remains, proxy evidence in the form of seed and other plant impressions can be observed in ceramic vessels, clay products and metal slag (Jessen and Helbaek 1944; Willcox and Fornite 1999; Reid and Young 2003). Preserved stomach contents and palaeofaeces (Hillman 1986) can supply direct evidence of foodstuffs consumed, providing information on the composition of meals. When compared with charred remains, material preserved under waterlogged and desiccated conditions can provide more information about contemporary environments. Wider

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varieties of plants may be preserved in waterlogged and desiccated deposits, as they do not require exposure to fire. When considering assemblages preserved under waterlogged conditions, one must remember, however, that some categories of plants appear to be very susceptible to degradation and rarely preserve, while others are extremely durable. More durable material may therefore be recovered in relatively larger quantities from deposits, such as certain fruit seeds, perhaps resulting in biased interpretations relating to their significance in the diet.

Interpretation of Data Recovery, identification and interpretation of plant macro-remains will provide information on past activities and environments (Fig. 11.1). The combination of diverse datasets of environmental remains and multi-proxy investigations will produce enhanced interpretations, when compared with any single approach. Where a range of remains is preserved, plant macro-remains data can be integrated with pollen, beetle and wood remains data to explore vegetation at various spatial scales (Weir and Conway 1988; Kenward and Hall 1995; Mason and Hather 2002).

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Figure 11.1: The interpretation of plant macro-remains’ data can provide a range of information on past societies and environments. A selection of references is provided for examples of studies, with a focus on those relating to Ireland: (1) Van der Veen 1992; (2) Kenward and Hall 1995; (3) Mitchell 1979; Connolly 1994; Lewis 2002; (4) Hather 1993; 2000; Van der Veen 1999; (5) Dennell 1976; Charles et al. 1998; (6) Zohary and Hopf 2000; (7) Hurcombe 2000; (8) Hall et al. 1984; (9) Hillman 1981, 1984a; Jones 1985; Van der Veen 1992; Smith 2001; Stevens 2003; (10) Zvelebil 1994; (11) Morrison 1994; Leach 1999; Stone 2001; (12) Dickson 1994; (13) Smith et al. 2001; (14) Dickson 1996; (15) Greig 1996; (16) Hillman 1982; Dineley 2004; (17) MacLean 1993; Dark 2004; (18) Monk 2000; (19) Fairbairn 2000; (20) Behre and Jacomet 1991.

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Stable-isotope analysis of human and animal bone collagen, particularly nitrogen isotopes, can provide information on the diets of mammals from which they were taken (for example, Schulting and Richards 2000). Molecular residue analysis of charred cooking residues can also indicate foodstuffs consumed (Copley et al. 2003), as can analyses of skeletal indicators relating to diet and health (Power 1993). The integration of documentary and ethnographic sources has been utilised to explore issues such as production methods, yields and social issues relating to the consumption of plants (Green 1984; Hillman 1984a; Jones 1984). Data from zooarchaeological records can also be useful when investigating arable farming systems, perhaps demonstrating interdependence between arable agricultural systems and animal husbandry (Charles et al. 1998). Most importantly, plant macro-remains analyses must be integrated with other elements of archaeological investigations, from artefact studies to theoretical narratives (Fredengren et al. 2004).

A History of Plant Macro-Remains Research Early Studies Renfrew (1973) has provided a general review of early plant macro-remains analyses, while Pearsall (2000) offers a more wide-ranging review of studies beyond Europe and the Near East. The comprehensive study of archaeological non-wood plant macro-remains commenced during the nineteenth century with the analysis of material such as the desiccated remains recovered from Egyptian tombs (Kunth 1826) and the waterlogged remains from Swiss Neolithic lakeside villages (Heer 1866). Analyses began in the Near East from around the middle of the twentieth century, with studies often focussing upon the evolution and domestication of crop plants

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(Helbaek 1966; 1969). Early plant macro-remains studies were often carried out by botanists without the implementation of systematic sampling strategies–archaeobotany tended to be a secondary study rather than one of the primary research aims of projects at this time.

‘New Archaeology’ and Innovative Approaches Plant macro-remains studies entered a new phase with the arrival of processual archaeology in the 1960s, heralding a period when archaeological investigations increasingly made use of ecological approaches, and specialist analyses of environmental remains became progressively more widespread. Archaeological studies became more rigorously descriptive, and cultural behaviour came to be viewed as adaptive, hence the focus on economic systems and resource exploitation. There has been a significant increase in the quantity of work being carried out worldwide since this period, coinciding with the introduction of innovative processing and identification techniques, such as the use of flotation in the processing of soil samples (Struever 1968; Van Zeist and Casparie 1984). In recent years, plant macro-remains studies have become more self-critical, with increased debate and discussion relating to issues such as taphonomy (Huntley and Stallibrass 2000). Ethnographic studies have been carried out to investigate issues relating to crop-processing techniques (Hillman 1973; 1981; 1984a; Jones 1984), while experimental archaeology has been utilised in the exploration of farming systems (Reynolds 1979; Robinson 1990). More recent

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approaches have established the use of Functional Interpretation of Botanical Surveys (FIBS), which is the application of functional attributes of weeds in order to distinguish between various agricultural regimes (Jones et al. 2000).

Post-processual Archaeology and Environmental Studies The advent of post-processual and more recent theoretical approaches in archaeology has prompted a shift towards the investigation of subjective behaviour in studies of material culture. Processual studies were considered by some to be overly-deterministic, with too much emphasis being placed upon societies being adaptive and responsive to environmental change. Environmental archaeology, together with its perceived ecological approaches, was unfortunately viewed as being too closely associated with processual archaeology, resulting to some extent in its marginalisation (Shanks and Tilley 1992, 34–6; Albarella 2001). The remains of plants such as cultivated crops are, however, cultural products (Thomas 2001, 56) and plant remains data have much to contribute in the construction of post-processual narratives. This has been cogently demonstrated with regard to the variety of ways in which plants relate to social practice (Hastorf 1993; 1996; 1998; Hastorf and Johannessen 1996; Skoglund 1999; Fairbairn 2000; Albarella 2001; Evans 2003; Fredengren et al. 2004). Studies relating to wild plants can also be used in the exploration of people’s engagement with landscapes, and in how people perceived and culturally modified landscapes in which they existed (Tilley 1994; 1996; Evans 2003). While an approach that is

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overly-environmentally deterministic is obviously inappropriate, it must, however, be considered that some environmental events may have been hugely influential in human activities (O’Connell 1990; Baillie 1998).

A History of the Study of Plant Macro-remains in Ireland As in other parts of the world, the earliest studies of plant macro-remains in Ireland were carried out by botanists and scholars investigating the Quaternary period (Mitchell 1946). The recovery of preserved plant material from archaeological deposits was occasionally mentioned in appendices to excavation reports (O’Connor 1941), but the material was often unquantified and presented without contextual information or interpretation. One of the first major studies to be carried out on Irish material was by Jessen and Helbaek (1944), when they undertook a comprehensive survey of prehistoric plant husbandry in Britain and Ireland, concentrating on the earliest occurrences of various cereals. Frank Mitchell also carried out a number of early studies, beginning in the 1930s. Mitchell’s main focus was on Quaternary issues and vegetation history sequences, but he also had a keen interest in archaeobotany, producing a volume on plant macro-remains recovered from Medieval excavations in Dublin (Mitchell 1987). Approaches to plant macro-remains research in Ireland have regularly been influenced by activities in neighbouring Britain. British workers such as Greig (1991) have produced studies that include Irish macro-remains data, but such studies are usually primarily focussed on British material, with few comparisons drawn with Irish and European assemblages.

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Mick Monk, a British worker specialising in the analysis of plant macro-remains, came to Ireland during the late 1970s, introducing more systematic methods for the sampling and recovery of archaeobotanical material in Ireland. Monk has authored a significant number of reports on plant macro-remains from Irish sites dating to a variety of periods, and has fostered the training of archaeobotanists with an archaeological background. An important study of Monk’s consists of a general review of material recovered from Irish archaeological sites (Monk 1986), while a number of his articles promote more sophisticated approaches to the interpretation of archaeobotanical data, particularly in relation to cultural issues (Monk 2000).

Current Issues Well-funded, interdisciplinary projects combining archaeological excavations with a range of environmental analyses including non-wood plant macro-remains have, unfortunately, only occasionally been carried out in Ireland (for example in Discovery Programme projects). The small number of archaeobotanists specialising in the analysis of plant macro-remains in Ireland has resulted in a situation where interpretations suggested by individual workers often fail to be critically discussed within the Irish community. Many Irish publications consist of reports on individual site assemblages. Such analyses are rarely fully integrated with archaeological evidence when overall excavation reports are being produced, as archaeobotany is often perceived as dealing with interactions between plants and various ecological factors rather than interactions between people,

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plants and environments. As a result, archaeobotanical data are not interpreted in a way that is meaningful to archaeology and the study of past social systems. Archaeobotany has great potential to be part of a larger study of cultural histories, and a small number of more wide-ranging Irish studies have illustrated this point (for example, Geraghty 1996; Tierney and Hannon 1997; McClatchie 2003; Fredengren et al. 2004). The utilisation of documentary sources and ethnographic data has also proved to be helpful in exploring the roles of various plants (Lucas 1960; Kelly 1997; Feehan 2003). Research areas have, however, been dominated by individual interests rather than any integrated and communally-constructed research strategies. This lack of cohesion in research, combined with the small number of studies being published, may go towards explaining why international audiences are often not well-informed about recent and current work in Irish archaeobotany.

Dissemination of Information There exist a variety of organisations that provide regular opportunities for discussion and publication of plant macro-remains analyses. The International Work Group for Palaeoethnobotany was established in 1969 in order to provide a forum for archaeobotanical research, with proceedings of these meetings being published in Vegetation History and Archaeobotany. The British-based Association for Environmental Archaeology holds regular meetings, the proceedings often being published, and also produces a journal, formerly Circaea, and more recently Environmental Archaeology. The Journal of Archaeological Science and organisations including the Quaternary Research Association

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provide further opportunities for discussion and publication. In Ireland, the Irish Quaternary Association, the recently formed Agri-History Society and the Association for Environmental Archaeology also provide opportunities for the presentation of current research.

Selection and Processing of Samples Archaeological fieldwork has the potential to generate enormous quantities of data (Orton 2000, 6–7) and the prioritisation of certain deposits through sampling allows us to focus on selected material best suited to the research aims of the project. The method of sampling employed will strongly influence later phases of analysis and interpretation (Van der Veen 1984, 193), and will depend on the project’s research questions, labour availability and the nature of deposits on individual sites. Sampling strategies must be planned in advance and be well-structured, while still retaining some flexibility in order to allow re-evaluation as the excavation progresses. Sampling for various analyses must also be co-ordinated. Practical concerns such as budgetary constraints, storage implications and the possibility of on-site processing will affect the chosen methodology. The suggested stages in the analysis of plant macro-remains are shown diagrammatically in Figure 11.2.

Sampling Methods It is often not practical to follow a ‘blanket sampling’ strategy, whereby all deposits are sampled. Blanket sampling can be inappropriate on sites, for example where there is evidence for intense long-term activity with complex stratigraphy. ‘Systematic sampling’, the term being used in its

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archaeological rather than statistical sense, is instead a popular methodology that can include various approaches, for example the sampling of a specified range of deposit types. ‘Simple random sampling’ occurs where deposits are sampled in a statistically random manner, perhaps using random number tables. Random sampling must be rigorously followed to be effective, but may miss significant deposits such as large concentrations of charred material. ‘Judgement sampling’ focuses on deposits that appear to be potentially rich and informative, such as concentrations of charred material. Judgement sampling is, however, heavily biased towards larger, more visible remains, such as nut shells and cereal grains, and other taxa such as cereal chaff and smaller seeds can be under-represented or absent. This is obviously an approach that should not be used on its own, but judgement sampling can be used along with random or systematic strategies. Another issue to consider is that plant macro-remains may not be homogenously distributed throughout a deposit. It is sometimes helpful to take a number of samples from a single deposit, particularly when the deposit is large, such as a ditch fill, in order to determine whether there is spatial patterning within a deposit. This is known as ‘scatter sampling’ (Lennstrom and Hastorf 1992).

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Figure 11.2: Suggested stages in the analysis of plant macro-remains. If the deposit contains charred material, it is suggested that 40 litres should be sampled from each deposit, or as much of the deposit as possible if its volume is below 40 litres (English Heritage 2002). Less can be taken when dealing with material preserved as a result of waterlogged conditions, in which case a sample of around 20 litres is appropriate, and such samples must remain moist after being collected. All samples should be kept in a cool, dark area and long-term storage should be 463

avoided to prevent deterioration of the sample. Deposits that are clearly disturbed, such as those affected by rodent burrows and modern plough zones, are not suitable for sampling, as their contents will be too mixed to allow interpretation.

Processing of Samples The sedimentary matrix in which the plant macro-remains are contained is disaggregated in order to extract the relevant material for analysis. The methodology followed for extraction will depend on the process by which the plant macro-remains have been preserved. Carbonised material is usually recovered by flotation, and this can often be carried out in the field. There is not a strong tradition of on-site flotation in Ireland, but this approach can be cost-effective, eliminating the need for storage of bulky samples prior to their delivery to the plant macro-remains analyst, and can be helpful in assessing the suitability of chosen sampling strategies when the excavation is still in progress. Differences in the density of organic and inorganic material mean that flotation is good method of separating the two from each other, as the specific gravity of water lies between that of organic and inorganic material. Flotation involves the placing of a soil sample into a container, then immersing the sample in water. When agitated, organic material such as charred plant macro-remains will be released from the soil matrix and float to the surface, or be suspended in the water, whereas inorganic material will sink to the bottom of the container. When dealing with heavy clays, the addition of ‘pre-treatments’ can sometimes be helpful in disaggregating the matrix. The floating organic material, or the ‘flot’, is

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poured into a bank of sieves containing various mesh sizes, the smallest being around 0.3 mm. This process is repeated until no more material is seen floating in the water. Inorganic material, as well as some denser organic material, will have collected at the bottom of the container. This is known as the ‘residue’ or ‘retent’ and can be decanted directly into a sieve containing mesh of 1 mm, and the contents washed in a concentrated flow of water. The flot and residue can be left to dry in sieves or on tightly woven cloths, such as muslin, while ensuring that the charred material is not handled when wet. Flotation systems of this type are reliant on human labour for the actual process of disaggregation. Mechanised flotation systems utilise air or water pressure that passes through the sample from below, the sample being held on mesh, in order to separate the sample. Pearsall (2000, 14–65) describes various flotation machines that have been developed. The development of flotation in the 1960s as a method for extracting remains resulted in a significant increase in the range and quantities of plant macro-remains recovered, as well as the increased recovery of artefacts from non-flot residues (Struever 1968). Remains preserved under waterlogged conditions can be extracted using the fine-sieving technique, and this method is best practised in a laboratory–such material must be kept wet, or will shrink and crack when dried. Fine-sieving is required as waterlogged material will not always separate and float when the flotation technique is applied. The sample should be placed into a sieve with mesh measuring 0.3 mm, or into a bank of sieves with the smallest mesh measuring 0.3 mm and the sample washed in a concentrated flow of water. When fine-sieving has been carried out, waterlogged material must be kept in watertight containers containing water or alcohol

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(Kenward et al. 1980). Flotation of samples prior to fine-sieving may sometimes be carried out in deposits where significant quantities of charred remains are mixed with waterlogged remains and, in this case, the residue only is fine-sieved. Fine-sieving can also be carried out without the use of water, which may be preferable when processing samples containing desiccated remains. Impressions of seeds, leaves, cordage and other organic material on a range of fabrics can be cast using various casting agents, such as silicone or casting gels used in dentistry, and it is the experience of this author that this work can be easily carried out in the field.

Scanning, Sorting and Identification The scanning, sorting and identification of plant macro-remains following sample processing must only be carried out by trained workers familiar with the various changes in appearance that the preserved remains may have undergone. Cereal grains may, for example, decrease in length, while increasing in width (Renfrew 1973, 13). Although whole cereal ears and fruits can occasionally be recovered (Maier 1996), fragmentation of material often occurs, and the analyst must therefore be trained in recognising fragments of preserved material and in distinguishing diagnostic breakage patterns. Depending on the quantity of processed material, it may be desirable to introduce sub-sampling with the use of a Riffle box, perhaps analysing only 50% or less of the sample, while still ensuring the examination of a representative quantity (Van der Veen and Fieller 1982).

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Scanning and Sorting The scanning and sorting processes aim to extract any non-wood plant macro-remains from the flots and fine-sieving material, and then sort the plant macro-remains into broad groupings. In the case of flots for example, non-wood remains must be separated from other organic materials, such as fragments of charred wood. The use of magnification may not be required for the scanning and sorting of remains larger than 2 mm. Any fractions under 2 mm can be examined using magnification of at least x 6–x 40, with an external light source such as fibre-optic lights.

Identification The identification of plant macro-remains is usually carried out by comparing gross morphological features and internal anatomies with those of modern plant components. Identification may also require the examination of cell patterns and various anatomical characteristics. A regional comparative collection of modern specimens (Nesbitt et al. 2003) and botanical illustrations (Beijerinck 1947; Katz et al. 1965; Berggren 1969; 1981; Anderberg 1994) are necessary for the identification of preserved material. Access to examples of non-native species that may have been imported, such as Ficus carica L. (fig), must be available. Collections of modern specimens should also include charred and dissected material. Identification of most plant macro-remains can be carried out using a light microscope, with magnification ranging from x 6 to x 40. Some remains may benefit from the application of other microscopy techniques such as scanning electron microscopy, which provides

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excellent depth of field and is used to determine minute anatomical structures (Butler 1991). Characteristics that will aid in identification include size and shape, texture, colour (if un-charred) and presence of scars and attachments. Sketching seeds can also be helpful in highlighting characteristics that might assist in securing identification. More careful description, measurement and illustration of remains can be useful in allowing comparisons of materials between sites, particularly when dealing with issues such as crop evolution in the analysis of cereals and pulses (Körber-Grohne 1991). Identification of vegetative parenchyma is enabled by the analysis of diagnostic morphological and anatomical characteristics, although this is possible for only a small percentage of fragments, as many are too small or poorly preserved to be identified (Hather 2000, 4). Features such as stomata cells, leaf outline and venation can aid in the identification of leaves. Leaf arrangement and bud-scales can also provide a guide to identification of stem material (Tomlinson 1985). The level of identification reached may depend on the state of preservation, the ability to determine differences in various species–which sometimes is difficult in genera such as Carex (sedges)–and on the completeness or otherwise of the reference collection used.

Quantification Numerical analyses of plant remains’ data can be carried out inductively and deductively in order to determine patterns in data (Jones 1991; Van der Veen 1992; Shennan 1997; Orton 2000). Such analyses do not necessarily depend on large

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datasets (Colledge 2001, 183). Quantification of data has the potential to determine patterns and trends, for example relating to landscape use at different times and in different locations by grouping samples from the same activity area, geographical region or chronological phase. Numerical analyses based upon the utilisation of raw counts of plant components recovered may, however, be inappropriate, as counting fragments can overstate levels of representation, thereby distorting statistical significance (Orton 2000, 149). Some species, such as fig, also produce very large numbers of seeds, again possibly contributing to biased interpretations.

An Irish Case Study: Tracing Agricultural Change at Kerlogue, Co. Wexford When recovery and identification of the plant macro-remains are completed, the next stage of analysis is interpretation of the data. All relevant contextual, phasing, dating and other archaeological information must be made available to the plant macro-remains analyst at an early stage to aid in interpretation of the plant material. The plant macro-remains assemblages analysed for this paper derive from the excavation of archaeological deposits at Kerlogue townland, Co. Wexford (excavation licence number 02E0606), which were investigated by Stafford McLoughlin archaeological consultancy in advance of a business park development (McLoughlin 2002a; 2002b). The site is located less than 2 km to the south of Wexford town and around 0.7 km from the modern shoreline (Fig. 11.3). Four areas of archaeological activity were recorded –Sites 2, 3, 4 and 5 (Fig. 11.4). Site 2 comprised a circular structure of Iron Age date, with numerous associated internal features. Excavations at Site 3 revealed Early Neolithic pits,

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an undated Iron Age gully and evidence for cultivation in the form of ard-marks. Sites 4 and 5 produced a range of features, including Early Neolithic pits, an Early Bronze Age pennanular ring ditch, undated gullies and Early Medieval pits. Animal bone was not recorded in deposits at Kerlogue. Cereal or possible cereal remains were, however, found in deposits dating to each period, and this section will focus on the significance of these remains in reconstructing activities at Kerlogue over several millennia.

Figure 11.3: Location map of archaeological site at Kerlogue, Co. Wexford.

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Figure 11.4: Plan of archaeological features at Kerlogue, Co. Wexford (after McLoughlin 2002a). Archaeological features shaded grey; modern furrows in white.

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The sampling strategy undertaken at the site was systematic, whereby efforts were made to sample a wide range of deposits, with judgement sampling being imposed in areas where concentrations of burning were recorded. Scatter sampling was also undertaken in some deposits (Table 11.1). Processing of the soil samples was carried out by the excavators, following consultation with the author. Approximately eight litres of soil were processed from each sample using the flotation method, with meshes ranging from 0.25 mm to 2 mm. The well-drained soils at the site resulted in the recovery of plant macro-remains that were preserved by charring, and the taxa recorded are presented in Tables 11.1 and 11.2. Plants are referred to by their Latin names, following nomenclature in Flora Europaea (Tutin et al. 1964–83) when mentioned for the first time, and are thereafter referred to by their common names if available. The modern ecology of plants, as indicated by regional floras, has been drawn upon in order to provide a general basis for the consideration of past plant communities. It should, however, be noted that modern descriptions of habitat preferences and ecological groupings cannot necessarily be applied to archaeological data without modification.

Early Neolithic Material The Early Neolithic deposits at Kerlogue consisted of pit fills at Site 3 and Site 5. A series of pits was recorded at Site 3, some of which contained worked flint and Early Neolithic pottery, the latter dated on typological grounds to the first half of the fourth millennium BC (McLoughlin 2002b). A series of ard marks was also located less than 5 m to the east of these pits, although they did not provide datable evidence. Ard

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marks thought to be associated with Neolithic activity have, however, previously been found elsewhere in Ireland (Byrne 1992). Three samples from two of the pit fills (Contexts 3a and 6a) at Site 3 contained shells of Corylus avellana L. (hazelnut) and grains of Triticum sp. (wheat). Some of the wheat grains were identified as possible Triticum dicoccum L. (emmer wheat) and a poorly-preserved glume base of a hulled wheat variety was also recorded (Fig. 11.5). Site 5 also produced a series of pits, some of which contained worked flint. Four fills from three of the pits (Contexts 6a, 10a, 11a and 11b) contained hazelnut shells and cereal grains. A fill of one of the pits (Context 10a) produced a large quantity of hazelnut shell fragments (Fig. 11.5), which were radiocarbon dated to 4970±45 BP (3810–3650 cal. BC; WK-13726). Significantly smaller quantities of hazelnut shell fragments were recovered from other Early Neolithic pit fills at Site 5. The pit fills also produced possible emmer wheat grains, a grain of Hordeum sp. (barley), cereal grains that could not be identified to genus, and a culm stem node and culm fragment of Gramineae (grass). The culm node and culm fragment may represent cereal remains, but both are poorly preserved. Many of the plant macro-remains recorded in Early Neolithic deposits at Kerlogue were poorly preserved, which may result from movement and fracturing of the remains prior to and post-deposition. Cereals were mainly represented by the recovery of grains, and relative to the grains, more fragile plant components, such as cereal chaff, may not have survived. The cereal remains recovered in these pits are likely to have been charred in fires elsewhere and would have been deposited in the pits at some later stage, thereby representing secondary or even tertiary refuse.

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Table 11.1: Taxa recovered from prehistoric deposits at Kerlogue. N=Neolithic; BA=Bronze Age; IA= Iron Age; UN= Undated. 474

Table 11.2: Taxa recovered from Early Medieval deposits at Kerlogue, Co. Wexford.

Figure 11.5: Examples of plant macro-remains recovered from Kerlogue, Co. Wexford. Left: Hazelnut shell fragments from an Early Neolithic deposit at Site 5 (Context 10a, Sample 17); Middle: Possible emmer wheat grains from an Early Neolithic deposit at Site 3 (Context 3a, Sample 3);

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Right: SEM image of hulled barley grain from an Early Medieval deposit at Site 5 (Context 1 d, Sample 24). Arable farming is thought to have been introduced into Ireland around 4000 BC, earlier dates than this having failed to gain widespread acceptance (O’Connell and Molloy 2001). The introduction of arable agriculture into Ireland represents not just the movement of crops, but also the transportation of knowledge involved in crop husbandry. The main significance of the Kerlogue material lies in its date and location, as it represents the earliest published macro-remains evidence for cultivated cereals in the Wexford region. Wexford is not an area that regularly appears in discussions relating to Early Neolithic activities in Ireland (Cooney and Mandal 1998; Cooney 2000) due to the comparative lack of archaeological remains discovered to date, although Green and Zvelebil’s work (1990; 1993) in nearby Co. Waterford has identified a number of Neolithic sites, as well as evidence for early agriculture. Excavations being carried out under the auspices of the National Roads Authority are also likely to enhance our knowledge of Early Neolithic activities in the south-east of Ireland. Emmer wheat has regularly been recorded in Irish Early Neolithic deposits (Monk 2000), for example at Tankardstown, Co. Limerick (Monk 1988), and Corbally, Co. Kildare (Purcell 2002), while barley has also been recovered (Jessen and Helbaek 1944; Monk 2000). Hazelnut shells are also regularly recorded in Neolithic deposits (McComb and Simpson 1999). The hazelnut shells recorded from Kerlogue are likely to represent food-waste that was burnt in order to reduce its mass, or could be the remains of material thrown onto the fire to increase its heat output. It has been suggested 476

that hazelnut shells are over-represented on Early Neolithic sites (Jones 2000, 80–1), as the shells are waste and are therefore likely to be burnt, which can lead to an over-estimation of the extent to which early farming communities relied on gathered foods.

Early Bronze Age Material An Early Bronze Age pennanular ring-ditch was recorded at Sites 4 and 5. A fill of the ditch, Context 3a, produced hazelnut shell fragments and a possible cereal grain. Cereal cultivation during the Bronze Age is thought to have been focused on the production of barley, with the occasional presence of wheat (Monk 1986), although this hypothesis is based mainly on evidence from seed impressions in ceramic vessels rather than charred remains. A more recent study focused on charred remains from Bronze Age sites in Ireland and suggests that whilst barley was certainly a significant crop at this time, evidence for wheat can also regularly be found (Fuller et al. in press).

Iron Age Material A circular structure at Site 2–comprising a slot trench, an internal ring of post-holes and other interior features–was dated to the Iron Age. Fills of the slot trench, Context 1, contained grains of wheat, wheat/barley and Avena sp. (oat), as well as a glume base of hulled wheat, a grass culm node and culm fragments. Hazelnut shell fragments and seeds of Polygonum sp. (knotgrass) were also recorded in Context 1, the latter representing a genus that can be seen growing in

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disturbed ground and arable fields. Prunus spinosa L. (blackthorn) and Salix sp. (willow) charcoal from Context 1 were radiocarbon dated to 2237±67 BP (410–110 cal. BC; WK-15498). The slot trench enclosed a number of features, including pits and post-holes. Context 7 was a sub-rectangular pit that contained cremated human bone, burnt stone and charred plant remains. Grains of wheat and barley were recorded in a fill of Context 7, in addition to grass culm node and culm fragments. A hazelnut shell fragment and a seed of Galium cf. aparine L. (cleaver) were also recorded. Cleaver can be found growing in range of habitats, including arable fields. Quercus sp. (oak) charcoal from Context 7 was radiocarbon dated to 2217±38 BP (390–170 cal. BC; WK-15497). Fills of two interior postholes, Contexts 2 and 71, also contained charred plant remains. Context 2 produced a barley grain and a grass culm fragment, while Context 71 contained burnt stone and a wheat grain. The Iron Age material from Kerlogue is significant, as a relatively small number of cereal grain assemblages dating to this period have been published in Ireland (Monk 1986). When compared with the Neolithic assemblage, a wider range of cereals is represented in Iron Age deposits at Kerlogue, possibly representing changes in agricultural techniques and strategies. There is evidence for the introduction of a range of new farming tools from the Bronze Age in Ireland (Eogan 1994), and soil-improvement techniques, such as manuring, may also have become more widespread. There is also further evidence for the management of landscapes, demonstrated, for example, by the increase in construction of field systems. The diversification in cereal types recorded is accompanied

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by a dramatic reduction in the occurrence of hazelnut shell when compared with Neolithic deposits at Kerlogue, suggesting that the gathering of this latter foodstuff had declined in importance. The quantity of cereal remains recorded in Iron Age deposits at Kerlogue is, however, similar to that present in Neolithic deposits. Naked and hulled barley are commonly recorded in late prehistoric deposits in Ireland, while oat occurs less frequently (Monk 1986). It has been suggested that oat was not cultivated until the Early Medieval period (Monk 1986), and its presence in late prehistoric deposits may therefore represent a wild variety. The cereal remains recorded in Iron Age deposits at Kerlogue are likely to represent secondary or tertiary refuse, having been charred in fires elsewhere prior to deposition in the slot-trench, pit, post-holes and gullies. The presence of cremated human bone in pits within the Iron Age circular structure suggests that this area may have been the focus of ceremonial activities associated with disposal of the dead. Cereal foodstuffs may have been an integral part of such activities, being consumed by the living and perhaps accompanying the dead.

Early Medieval Material Two Early Medieval pits that may have functioned as hearths in Sites 4 and 5 contained a substantial quantity of plant remains (Table 11.2). Contexts 1 and 2 were large, oval pits, and the base of each pit was burnt. The quantity of cereal remains observed after flotation of fills of Context 1 was substantial, and it was decided that the identification of a maximum of c. 500 whole seeds/grains from each layer in Context 1 would be representative of the cereal remains

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present. The sample from Context 1a was examined in its entirety and, with the use of a Riffle Box, sub-samples of two other deposits in Context 1 were analysed: approximately 50% of Context 1b and approximately 15% of Context 1d. It is estimated that Context 1b therefore contained c. 3500 components and Context 1d contained c. 13,000 components. Hulled barley grains were predominant in both pits, including both asymmetrical and symmetrical grains. The recording of asymmetrical grains indicates the presence of six-row barley, as two-row barley crops consist solely of symmetrical grains. The ratio of asymmetrical grains to symmetrical grains in a six-row barley crop is 2:1. The ratios of asymmetrical to symmetrical grains encountered in Contexts 1b, 1d and 2a range from 1.18:1 to 1.56:1, reflecting the predominance of six-row barley in these deposits. The recovery of asymmetrical grains in Context 1a also reflects the presence of six-row barley in this deposit. Smaller quantities of Triticum sp. (possible free-threshing wheat) and oat grains were recorded in both pits, as well as more substantial quantities of poorly-preserved cereal grains that were indeterminate to genus. Context 1 contained a small quantity of hazelnut shell fragments, a grass culm node, and seeds of knotgrass and Polygonum persicaria L. (redshank). Context 2 also contained redshank seeds, representing a species that can be found growing in a variety of environments, including disturbed ground and arable fields. Charred cereal grains from Context 1 were radiocarbon dated to 1541±38 BP (420–610 cal. AD; WK-13725). Hulled wheat was not recorded in the Early Medieval deposits at Kerlogue, providing a contrast with prehistoric deposits at this site. In common with Iron Age deposits at Kerlogue, there are also very few occurrences of hazelnut shell in Early Medieval deposits.

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Despite the large number of fragmented cereal grains in Contexts 1 and 2, many of the whole cereal grains were relatively well-preserved when compared with prehistoric cereal remains at Kerlogue (see Fig. 11.5). If the grains were burnt within these pits, some of them may not have been subject to a great deal of movement after being burnt, thereby explaining their better condition. Although large numbers of cereal grains were recorded, a very small quantity of chaff and weed seeds was present in Early Medieval deposits at Kerlogue, suggesting that the cereal crops were well cleaned of contaminants before entering these deposits. The relatively small quantity of cereal grains, as well as weed seeds and chaff, in prehistoric deposits at Kerlogue precludes such a comparison. When pit fills produce substantial quantities of cereal remains, it is sometimes assumed that the pits functioned as grain-storage pits. Such an interpretation is, however, problematic, as cereal remains can often comprise secondary and tertiary deposits emanating from fire-waste, rather than primary deposits (Fuller et al. in press). The evidence for in-situ burning in these Early Medieval pits, and the relative lack of other food debris does, however, suggest that these pits may at some time have been used in the processing of crops or preparation of foodstuffs. There is a significantly higher quantity of cereal remains in Early Medieval deposits at Kerlogue when compared with prehistoric deposits. This may result from the Early Medieval cereal remains being located in their primary context, but may also indicate changes in farming strategies over time. Archaeological and documentary evidence from many parts of Ireland suggest a general increase in arable farming dating

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to the Early Medieval period (Fredengren et al. 2004). It seems that the climate from the second to the mid-sixth century AD in Ireland was well suited to crop cultivation (Lamb 1981). Despite the possibility of climatic deterioration occurring around the middle of the sixth century (Baillie 1993), there seems to have been further arable expansion during the eighth and ninth centuries, with many horizontal mills being constructed at this time (Rynne 1998). The operation of these mills suggests changes in the management of agriculture and larger-scale production. In addition to the substantial quantity of cereal grains from Early Medieval deposits at Kerlogue, there is a clear focus on production or consumption of one type of cereal–six-row hulled barley–perhaps reflecting larger-scale production of this cereal type for the creation and eventual redistribution of crop surpluses. Six-row hulled barley is a relatively hardy crop that can be used in human and animal foodstuffs. Early Medieval documentary sources indicate that differing levels of status were attached to various cereal types. Bretha Déin Chécht, an eighth-century law text, provides a list of seven cereal types, whose order is based on the relative prestige of each type of grain, which is correlated with a particular grade in human society (Bretha Déin Chécht §1–2; Binchy 1966; Kelly 1997). Triticum aestivum L. (bread wheat) and then Secale cereale L. (rye) are placed at the top of the list, with different types of hulled wheats and barley further down, and finally oat. Bread wheat is equated with the rank of superior king, bishop or chief poet, whereas at the other end of the scale, oat is equated with the commoner. Oat and barley are more regularly recovered from archaeological deposits in Ireland, therefore reflecting their lower status (Monk 1991). Bread

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wheat and rye are rarer in the archaeological record, as their status was perceived as being higher. Cereals were therefore regarded not just as a source of sustenance, but also as cultural symbols that could distinguish social classes. The recovery of possible free-threshing cereal grains at Kerlogue, which may be of bread wheat, indicates that people involved with activities at this site had access to higher-status cereals. Six-row barley is, however, second-last in the eight-century list of cereals, and the recovery of a far more substantial quantity of six-row barley grains demonstrates that activities at Kerlogue were more usually associated with the lower end of the social scale. A number of undated gullies was also recorded at Site 3 and Site 4/5. Context 7 at Site 3 was interpreted as a gully, and this deposit contained flint and grains of barley, including Hordeum nudum L. (naked barley), in addition to culm node and culm fragments. Context 16 at Site 4/5 was also interpreted as a gully, containing burnt stone and six-row hulled barley.

Overview of Material from Kerlogue Archaeobotanical analysis of deposits at Kerlogue provides evidence for activities associated with arable agriculture at this site over several millennia. Changes can be observed in the types of cereals encountered over time, and also in the quantities of cereals preserved. Hulled wheat is only represented in prehistoric deposits, particularly in Early Neolithic deposits, whereas free-threshing wheat is confined to deposits of the historic period. Indeed, archaeobotanical 483

evidence from other sites suggests that large-scale production of free-threshing wheat is not observed until the Medieval period in Ireland (Monk 1986). Six-row hulled barley meanwhile, appears to be of far greater significance during the Early Medieval period. It has been suggested in this paper that these changes may result from a range of factors, including improved soil management and harvesting techniques, climatic influences, market requirements and social constraints. The nature of activities on the site is also likely to have been influential. Smaller quantities of remains were recorded in Iron Age deposits associated with ceremonial activities, while more substantial quantities were present in Early Medieval pits that may have been linked to more domestic pursuits. Ard marks at Kerlogue provide evidence for the cultivation of crops at this site, although the phase in which this activity was carried out is unclear. There is also regular evidence for gathered foodstuffs at Kerlogue in the form of hazelnut remains. Large quantities of hazelnut shell were recorded in early prehistoric deposits, but this resource seems to have decreased in significance during later periods. There is little archaeobotanical evidence for plants growing in the local environment surrounding the site at Kerlogue. Seeds of the knotgrass genera and cleaver were occasionally recorded, but these plants may have been growing alongside cereals in arable fields, and their seeds inadvertently harvested. The value of any plant is, however, determined by the perceptions of its viewers. Many plants that we would consider to be weeds may have been considered useful in past societies, for example in contributing to food resources and medicines. Such plants may not have been prepared in the vicinity of fires, thus reducing their likelihood of being

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charred and preserved. Similarly, the absence of vegetable and fruit remains from Kerlogue does not indicate that such foodstuffs were not utilised, as they may also have been consumed without coming into contact with fire.

Potential, Prospects and Opportunities It seems clear that the analysis of plant macro-remains has the potential to inform us on an ever-widening range of archaeological issues. But who sets our agenda? Research pursued often seems to be structured chiefly by archaeological work, and while the need to ensure relevance to the archaeological community is essential, plant macro-remains analysts must also form regionally-based research agenda that are known throughout the archaeobotanical community in Ireland, as well as by archaeologists and other environmental analysts. This must be carried out with regard to the restricted budgets and timeframes that now affect much archaeological practice within Ireland. The integration of plant macro-remains analyses with other approaches could also contribute to more widespread current interests in Ireland, for example in the recreation of traditional farming practices and in assessing the impact of humans on various ecosystems, thereby contributing at some level to social policy. Other opportunities for future research in Ireland include the more comprehensive integration of ethnographic information with plant macro-remains data. Archives can be consulted from a number of sources in Ireland, including the Congested Districts Boards, folklife sections of museums, farming organisations such as Teagasc, the Folklore Commission, the Schools Folklore Collection and photographic archives. Studies in Ireland would also

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greatly benefit from being broadcast more regularly to wider international audiences, and also in receiving increased peer-review and feedback from such audiences. Many plant macro-remains analyses are, unfortunately, unpublished, and there is an urgent need for an injection of funding in order to collate and assess the data that are being accumulated. The validity of comparisons drawn between various assemblages represents another area that should be focussed upon. Government organisations with responsibility for the monitoring of methods used in archaeological excavations have not given sufficient attention to the implementation of structured sampling strategies on archaeological excavations, resulting in a situation where the quality of plant macro-remains data is extremely variable. It is through the increased dissemination of data and interpretations relating to plant macro-remains analyses that such problems can be tackled, thereby demonstrating the relevance and necessity for the continuation and improvement of archaeobotanical investigations.

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Stevens, C. J. 2003. An investigation of agricultural consumption and production models for prehistoric and Roman Britain. Environmental Archaeology 8, 61–76. Stone, G. D. 2001. Theory of the square chicken: advances in agricultural intensification theory. Asia Pacific Viewpoint 42, 163–80. Struever, S. 1968. Flotation techniques for the recovery of small-scale archaeological remains. American Antiquity 33, 353–62. Thomas, K. 2001. Environmental archaeology is dead: long live bioarchaeology, geoarchaeology and human palaeoecology. A comment on ‘Environmental archaeology is not human palaeoecology’, pp. 55–8 in Albarella, U. (ed.), Environmental Archaeology: Meaning and Purpose. Dordrecht: Kluwer Academic Publishers. Tierney, J. and Hannon, M. 1997. Plant remains, pp. 854–93 in Hurley, M. F., Scully, O. M. B. and McCutcheon, S. W. J., Late Viking Age and Medieval Waterford Excavations 1986–1992. Waterford: Waterford Corporation. Tilley, C. 1994. A Phenomenology of Landscape: Places, Paths and Monuments. Oxford: Berg. Tilley, C. 1996. An Ethnography of the Neolithic: Early Prehistoric Societies in Southern Scandinavia. Oxford: Oxford University Press. Tomlinson, P. 1985. An aid to the identification of fossil buds, bud-scales and catkin-bracts of British trees and shrubs. Circaea 3, 45–130.

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Tutin, T. G., Heywood, V. H., Burges, N. A., Valentine, D. H., Walters, S. M. and Webb, D. A. 1964–83. Flora Europaea (Volumes 1–6). Cambridge: Cambridge University Press. Van der Veen, M. 1984. Sampling for seeds, pp. 193–9 in Van Zeist, W. and Casparie,W. A. (eds.), Plants and Ancient Man: Studies in Palaeoethnobotany (Proceedings of the 6th Symposium of the International Work Group for Palaeoethnobotany). Rotterdam: Balkema. Van der Veen, M. 1992. Crop Husbandry Regimes: An Archaeobotanical Study of Farming in Northern England 1000 BC –AD 500 (Sheffield Archaeological Monographs 3). Sheffield: J. R. Collis Publications. Van der Veen, M. 1998. A life of luxury in the desert? The food and fodder supply to Mons Claudianus. Journal of Roman Archaeology 11, 101–16. Van der Veen, M. 1999. The economic value of chaff and straw in arid and temperate zones. Vegetation History and Archaeobotany 8, 211–24. Van der Veen, M. and Fieller, N. 1982. Sampling seeds. Journal of Archaeological Science 9, 287–98. Van Zeist, W. and Casparie,W. A. (eds.) 1984. Plants and Ancient man: Studies in Palaeoethnobotany (Proceedings of the 6th Symposium of the International Work Group for Palaeoethnobotany). Rotterdam: Balkema. Weir, D. A. and Conway, M. 1988. Haughey’s Fort: a preliminary palaeobotanical analysis. Emania 4, 28–31.

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Willcox, G. and Fornite, S. 1999. Impressions of wild cereal chaff in pisé from the 10th millennium uncal B.P. at Jerf el Ahmar and Mureybet, northern Syria. Vegetation History and Archaeobotany 8, 21–4. Wilson, D. G. 1984. The carbonisation of weed seeds and their representation in macrofossil assemblages, pp. 201–6 in Van Zeist, W. and Casparie, W. A. (eds.), Plants and Ancient Man: Studies in Palaeoethnobotany (Proceedings of the 6th Symposium of the International Work Group for Palaeoethnobotany). Rotterdam: Balkema. Zohary, D. and Hopf, M. 2000. Domestication of Plants in the Old World (third edition). Oxford: Oxford University Press. Zvelebil, M. 1994. Plant use in the Mesolithic and its role in the transition to farming. Proceedings of the Prehistoric Society 60, 35–74.

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Acknowledgements I would like to thank Phil Austin, Sue Colledge, Dorian Fuller, Gordon Hillman, Mark Keegan, Mick Monk, Clive Orton and Ken Thomas for discussion relating to issues raised in this paper. I am very grateful to Allan Hall for helpful comments on an earlier draft of this paper, and would also like to thank this volume’s editors, Eileen Murphy and Nicki Whitehouse, for their advice and patience. The production of illustrations was enabled by the creativity and expertise of Mark Keegan, and thanks also to Sandra Bond and Kevin Reeves for assistance with production of photographs. I would finally like to thank Catherine McLoughlin and Emmet Stafford of Stafford McLoughlin Archaeology for their enthusiasm and ready provision of information regarding archaeological deposits at Kerlogue, Co. Wexford.

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12 Pollen Analysis and Archaeology in Ireland Gill Plunkett

Abstract Pollen analysis is a well-established technique that enables the reconstruction of past vegetation changes in the landscape. From an archaeological perspective, pollen records contain an important history of human interference with the natural environment and provide further insights into human activity that can greatly complement and augment the archaeological record. This paper examines the role pollen analysis has played in archaeological research in Ireland and draws on three cases studies to illustrate the diverse contributions it can make to the study of past human activity. The debate concerning the Elm Decline and the earliest farming in Ireland portrays the complexity of interpreting the pollen record, but also draws attention to the potential of the technique to shed light on activity not evidenced in the archaeological record. Recent findings from pollen studies near Late Bronze Age hillforts are also discussed that reveal the economic basis underlying the construction and occupation of these sites. Finally, extensive pollen evidence from the Late Iron Age and Early Medieval periods shows that a widespread expansion in farming pre-empted the

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arrival of Christianity in the island, although further intensification of agriculture is associated with the founding of monastic enclosures and the proliferation of secular sites in the seventh century. The pollen record during this period complements the available archaeo-environmental and literary evidence for a well-developed, mixed agricultural economy, highlighting the extent of the anthropogenic impact on the landscape at this time.

Introduction Pollen is the collective name for the gametophyte produced by all flowering plants. The cell walls of pollen are composed of sporopollenin, a compound that is highly resistant to decay and becomes subfossilised under suitable conditions. The morphology of the wall structure varies from plant to plant, making it possible to distinguish pollen grains of particular families, genera and sometimes species of plants (Fig. 12.1). Produced in abundance, an assemblage of subfossil pollen grains can provide an indication of the vegetation that once grew in a locality. Changes in the relative representation of plants over time can therefore be related to changes in the vegetation cover. Pollen analysis was first described as a technique for reconstructing vegetation histories in a lecture by Swedish geologist Lennart von Post in Oslo in 1916 (von Post 1967) and was subsequently employed to reconstruct climate change (e.g. Iversen 1944). The term palynology refers to the related but broader study that includes also plant spores, fungal, algal and other microscopic remains frequently encountered in subfossil pollen samples and referred to as ‘palynomorphs’.

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Figure 12.1: Images of some commonly encountered pollen types: (a) Pine (Pinus sylvestris), (b) Oak (Quercus), (c) Ash (Fraxinus excelsior), (d) Hazel (Corylus avellana), (e) Grass (Gramineae), (f) Goosefoot (Chenopodium album). Note: not to scale.

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By far the greatest amount of palynological research in Ireland is conducted on lake and peat deposits. As sediments build up gradually year after year in lakes and bogs, they capture a record of changing pollen influx in stratified sequences sometimes spanning long periods of time. Lake and peat deposits, by virtue of their anaerobic conditions, also tend to provide an ideal preservation environment for pollen and other microfossils. In raised and blanket bogs, pollen deposition is predominantly through aeolian processes, and will derive from a combination of local, intermediate and regional vegetation. In lakes and fens, pollen can also be carried to the site via rivers and streams that feed into the lake, and the pollen record therefore includes a representation of the lake catchment. While such sequences mainly register vegetation histories of an area, from an archaeological point of view, it is primarily the recognition of human-induced changes in the vegetation that are of concern. These changes can be manifested through alterations or reductions in forest cover, an increase in apophytes (native plants promoted by human activity, e.g. ribwort plantain (Plantago lanceolata), sheep’s sorrel (Rumex acetosella)) and/or the appearance of anthropochores (plants that could only have been brought in by human agencies, e.g. cultivars such as cereals or alien weeds such as cornflower (Centaurea cyanus)). Microscopic charcoal is also frequently encountered on pollen slides and, although this can be produced by natural fires, it too can be an indicator of human activity. Expressions such as ‘palynoarchaeology’ (Groenman-van Waateringe 1988) and ‘anthropopalynology’ (Edwards 1991) have sometimes been coined to describe the specific application of pollen analysis to address archaeological questions although such terminology has not gained currency.

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Pollen analysis can be conducted on archaeological sediments (for example, occupation layers or pit fills) but pollen preservation in mineral soils is often poor due mainly to biological attack by bacteria and fungi (Havinga 1971). It is not uncommon to find overrepresentation of the more resistant types, such as thistles (Compositae Subfam. Cichorioideae) and polypody (Polypodium) fern spores, while pollen from some of the main arboreal taxa such as hazel (Corylus), alder (Alnus) and ash (Fraxinus) can disappear almost entirely in certain soil types. The movement of pollen grains through a soil profile by faunal activity (e.g. earthworms, ants) can also be problematic (Havinga 1974). Waterlogged sediments, on the other hand, provide more suitable conditions for pollen preservation. In the inner ditch fill at Haughey’s Fort, Co. Armagh, Weir (1993a) recorded a high incidence of cereal-type (Cerealia-type) pollen, suggesting crop processing at the site, and the subsequent increase of scrub vegetation most likely reflects abandonment of the hillfort. At Newgrange, Co. Meath, pollen recovered from turves used in the construction of the main passage tomb suggested that the turves derived from damp pastures in the river valley (Groenman-van Waateringe and Pals 1982). The pollen spectra revealed a fairly open landscape with some evidence for crop cultivation in the area. Since the outset of pollen studies in Ireland, their value to archaeological research has been prominent. This paper will provide an outline of the leading personalities who have played a role in the integration of pollen and archaeological research through the last century. The main methodological considerations in pollen analysis, ranging from site selection to the construction and interpretation, will be summarised. Finally, three case studies will be presented to illustrate some

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of the diverse contributions pollen studies can make to the understanding of past human activity. The examples chosen focus on the Early Neolithic and the first emergence of farming, the economic basis of Late Bronze Age hillforts and the agricultural expansion that heralds the Early Medieval period.

A Brief History of Archaeology-Related Pollen Studies in Ireland The first application of pollen analysis in Ireland was undertaken by Gunnar Erdtman, who examined 15 sites and put forward the earliest scheme outlining the main post-glacial vegetation developments for the island (Erdtman 1928). The primary archaeological find to be the focus of pollen investigations was the wooden cauldron from Altertate, Co. Monaghan, for which it was hoped that the new technique would resolve the question of its age (Mahr 1934a). The Committee for Quaternary Research, established in 1933, firmly embodied the fusion of natural sciences and archaeology. From its outset, the Committee aimed to examine pollen records at no less than 30 archaeological sites across Ireland (Mahr 1934b). Its pollen analyst was Knud Jessen, who had undertaken the Altertate study, and who anticipated that archaeological remains would in turn contribute to the establishment of chronologies for distinctive peat horizons in Irish bogs (Jessen 1934). Recognising that pollen analysis was not limited to providing relative dates for archaeological features, Mahr (1934b) envisaged a more substantive role in which the technique would provide a new dimension to the study of past human activity, by throwing light on past settlement patterns and social organisation. The publication of the results 15 years later (Jessen 1949) brought Irish pollen analytical studies to the forefront in Europe. 511

From the 1940s, work by Johannes Iversen in Denmark on the identification of the pollen of herbs, and specifically agricultural weeds, greatly advanced the understanding of past human impact on forests (Iversen 1941). Through much of the early and mid-twentieth century, Frank Mitchell, a multi-talented Quaternary scientist who trained under Jessen and Iversen, became the leading Irish palynologist. Mitchell’s work included pollen records at more than 100 localities, on the basis of which he redefined the scheme for Irish post-glacial vegetational developments (Mitchell 1951; 1956). Many of the studies related directly to archaeological sites or finds, such as those at Lough Gur, Co. Limerick (Mitchell 1953–1954), Clonsast, Co. Offaly (Mitchell 1956), and Littleton Bog, Co. Tipperary (Mitchell 1965), and Mitchell’s interest in archaeological questions brought him to conduct several excavations, including those at Rockmarshall, Co. Louth (Mitchell 1947; 1949), Toome, Co. Derry (Mitchell 1955), and Lough Derravaragh, Co. Westmeath (Mitchell 1972). Although rudimentary in comparison to later pollen investigations, the research conducted by Jessen and Mitchell substantially outlined the major post-glacial vegetation history for the greater part of Ireland (Fig. 12.2). In the 1950s, the Nuffield Foundation, the forerunner of today’s Palaeoecology Centre at Queen’s University Belfast, was established. Alan Smith, the palynologist in the Centre, took a special interest in discerning evidence for early agriculture. From the 1960s, and with the aid of radiocarbon dating, Smith and his student Jonathan Pilcher identified in the pollen record patterns of vegetation change relating to human activities associated with the now renowned archaeological sites of Ballynagilly and Beaghmore, Co. Tyrone (Pilcher 1969; 1970; Pilcher et al. 1971; Pilcher and

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Smith 1979), and Newferry, Co. Antrim (Smith 1975; 1981; 1984). Importantly, Smith (1970; 1984) drew attention to the possibility of human impacts on vegetation prior to the onset of farming about 6,000 years ago, an aspect of enquiry that had previously been given little consideration.

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Figure 12.2: Schematic pollen diagram illustrating the main vevgetation changes in post-glacical Ireland. From the Neolithic period onwards, human interference with the forests leads to significant variations in vegetation patterns across Ireland. The re-introduction of pine and the appearence of non-native spruce and sycamore ca usually be seen foolowing the seventeenth century Plantation of Ireland. In the 1980s, the Palaeoenvironmental Research Unit was established at the National University of Ireland, Galway, with Michael O’Connell as the principal palynologist, joined later by Karen Molloy. Both researchers significantly extended the study of prehistoric farming into the west of Ireland (Molloy and O’Connell 1987; 1991; 1993; 1995; 2004; O’Connell 1980; 1986; 1990; 2001; O’Connell et al. 1988; 2001; O’Connell and Molloy 2001), with numerous detailed investigations relating to pre-bog field systems in Counties Mayo and Galway. In the south-west of Ireland, Ann Lynch’s (1981) study of the vegetational history at a number of locations in southern Kerry and Cork was the first to challenge the prevailing notion that this region was largely unpopulated during the earlier prehistoric period, while Mitchell (1989) reconstructed the complex history of human interaction with the environment on Valencia Island through the post-glacial period. More recently in the region, palynological investigations have been conducted by Tim Mighall and his colleagues in the vicinity of Bronze Age copper mines, enabling yet another aspect of past human activity to be examined within a palaeoenvironmental context (Mighall et al. 2000; Timpany et al. 2002). From the late 1980s, studies by Valerie Hall at Queen’s University Belfast turned attention to landscape change in the 514

historic period (Hall 1989a; 1990; 1994; 1998; 2003; Hall et al. 1993; Hall and Bunting 2000), with the dating of pollen studies greatly enhanced by the application of tephrochronology since the 1990s (see Pilcher, this volume). The identification of tephra horizons of known age (e.g. ash from the AD 1104 eruption of Hekla, Iceland) within peat deposits meant that pollen records from these sequences could be compared within a robust framework of precise, time-stratigraphic boundaries.

Methodologies in Pollen Analysis The first consideration in any pollen investigation must be the selection of an appropriate sampling site, and this will be governed by the research questions being posed as much as the availability of suitable deposits. Samples taken from the centre of a large bog or lake will record the major vegetation trends within a wide region, and are suitable for generalised or broad landscape studies that can demonstrate that human activity took place in the surrounding area. Such a record, however, can substantially obscure small-scale or localised changes. Profiles from the periphery of a bog, from bogs or lakes with smaller pollen catchments, or from small peat-filled depressions such as tree throw pits are better suited for the detection of more restricted human impacts if, for example, they are located, judiciously or by chance, in proximity to a known archaeological site. In optimal situations, a series of pollen records from multiple locations in a given bog or lake can be compared to enable the approximate location of the activity to be deduced (Turner 1975). Peat and lake sediments are typically collected for pollen studies by coring (Fig. 12.3), and a range of corers have been

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developed for precisely this purpose. In bogs that have been subject to peat extraction, open sections can facilitate the collection of material in monolith tins (Fig. 12.4). These have the advantage of enabling a large, intact block of peat to be sampled, which can then be used for multiple proxy studies, eliminating the need to cross-correlate series of non-contiguous cores. Open sections, however, rarely expose the entire depth of the bog, and complete sequences may not be obtainable in this manner.

Figure 12.3: Collection of peat samples for pollen analysis by coring from an intact bog surface using a Russian corer. Figure 12.4: Collection of peat samples for pollen analysis by extracting a monolith tin from an exposed peat face.

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Methods for the extraction of subfossil pollen from sediments are well-established (see Faegri and Iversen 1989; Moore et al. 1991) and the main procedures are outlined in Table 12.1. Samples are mounted on slides and examined under high power microscopes, typically at magnifications of x 400 for routine counting, and x 1,000 for critical identifications. Numerous keys exist to aid pollen identification (e.g. Faegri and Iversen 1989; Moore et al. 1991; Punt et al. 1976– Stage

Meth od

Pur pose

Subsampling

sample depth ideally confined to 1 cm or less

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Volume measurement

typically 1–2 cm3

for concentration calculations

Addition of exotic spores

Lycopodium clavatum tablets or solution; tablets dissolved with a few drops of hydrochloric acid

for concentration calculations

Deflocculation of sediment

dilute potassium hydroxide

for use on peat or organic-rich material

sodium pyrophosphate

for use on mineral-rich sediment

120 μm (filtrant retained)

removes coarse material

10 μm (residue retained)

removes finest material

acetolysis mixture (9 parts acetic anhydride: 1 part sulphuric acid); preceded and followed by glacial acetic acid wash to prevent reaction

breakdown of plant cellulose in sample

Sieving

Acetolysis

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with water in sample Hydrofluoric acid treatment

hydrofluoric acid; preceded by dilute hydrochloric acid treatment if samples are carbonate-rich

dissolution of minerals and silica

Staining

safranin or fuchsin

helps to bring out the surface sculpturing features of the pollen grains

Mounting medium

glycerol or silicon oil (preceded by series of alcohol washes to dehydrate sample)

for transference of sample to slide and storage

Table 12.1: Outline of the main stages of sample preparation in pollen analysis.

2003), but a reference collection of modern specimens is essential to distinguish many of the rarer taxa. A minimum pollen sum of 500 land pollen should be counted to gain a statistically valid representation of the flora, but sums in excess of 1,000 grains are preferable to address questions relating to human impacts. Sampling intervals will vary 519

according to the purpose of the study and the accumulation rate of the deposit, but should generally aim to represent as small a time interval as possible. Contiguous samples may be required in instances where the identification of human activity is central to the study. Specialist software has been developed for the drawing and analysis of pollen diagrams, such as Tilia, Tilia.Graph (Grimm 1991–93) and the more user-friendly TGView (Grimm 2004), and Psimpoll (Bennett 1994). Until the 1950s, the dating of pollen diagrams was determined by the recognition of main vegetational events such as the arrival of alder c. 7000 BP (c. 5800 cal. BC). Radiocarbon dating has since highlighted the non-synchronous nature of these events in different areas (Smith and Pilcher 1973), but has at the same time made it possible to obtain independent dates for horizons in a peat or lake profile. From the 1990s, the recognition of tephra horizons both in peats and lake sediments has also provided ready time-stratigraphic markers that have the additional benefit of allowing profiles from different sites to be matched precisely where the same tephras are present (e.g. Hall et al. 1993; Hall 2003). Ireland’s location in proximity to Iceland is especially favourable in this respect as ash clouds from Icelandic eruptions frequently extend across north-west Europe. Interpretation of anthropogenic activity through pollen analysis requires an understanding of the ecological preferences of the plants encountered, as well as an appreciation of the limits of the technique, as not all plants are equally represented in the pollen record due to variations in pollen production rates, dispersal mechanisms and resistance to decay. The distinction of various types of human activity

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must take into consideration the range of taxa present, the possible plant communities from which they derive and also the edaphic conditions surrounding the study area (Behre 1981). Where large datasets are available, such distinctions can be aided by statistical analyses to identify recurrent plant groups and by a comparison of these groups with modern human-influenced vegetation types (e.g. Birks et al. 1975; Turner 1986; Prøsch-Danielsen and Simonsen 1988; Gaillard et al. 1992). A good knowledge of the archaeological record of a region is also indispensable for reconstructing the nature of human impact on the landscape.

The Pollen Record and Archaeology in Ireland: Some Case Studies The application of pollen analysis to archaeological questions in Ireland has often tended to focus on establishing patterns of human activity around a given location, in some instances in the immediate vicinity of archaeological sites. As pollen records have grown in number, as methodological considerations have been refined and as chronological control has increased, however, the scope of information that can be gleaned by this record extends far beyond individual site studies. Palynological studies offer a further dimension to archaeological research, providing glimpses of past human activities that cannot always be reconstructed on the basis of archaeological evidence alone; at times the pollen record has even challenged archaeological assumptions and stimulated important debate. The following case studies outline some of the many ways in which pollen analysis has contributed to our understanding of the cultural past. The locations of the sites referred to in this section are shown in Figure 12.5.

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The Beginnings of Farming and the Elm Decline The beginnings of the Neolithic period in Ireland have long been characterised by the appearance of monumental burials and a new material assemblage including pottery, as well as a change in subsistence economy entailing the introduction of animal husbandry and arable agriculture. Radiocarbon dating evidence places the emergence of this new culture at c. 4000 cal. BC, although there has been considerable discussion amongst archaeologists in Britain and Ireland about whether the transition to the new way of life was fairly abrupt (Kinnes 1988), or somewhat more gradual (Cooney and Grogan 1994). In Ireland, the progenitors of the domesticated plants and animals, with the exception of pig, are absent prior to the Neolithic and represent introductions to the island.

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Figure 12.5: Map of Ireland showing the principal sites referred to in the text–1: Cashelkeelty; 2: Ferriter’s Cove; 3: Navan Fort, Haughey’s Fort and Loughnashade; 4: Downpatrick; 5: Rathgall; 6: Mooghaun Fort, Mooghaun Lake and Caherkine Lough; 7: Dún Aonghasa; 8: Ballylin Fort and Moyreen Bog; 9: Mayo Abbey and Lough Fark; 10: Abbeyknockmoy; 11: Clonmacnoise and Mongan Bog; 12: Ballywillin Lough; 13: Lios Lairthín Mór. As the primeval forest was opened up for pasture and crop-growing, the impact of farming on the Irish landscape from c. 4000 cal. BC is evidenced in numerous pollen diagrams by reductions in arboreal pollen and corresponding expansions in grasses, herb and weed taxa, including sometimes cereal-type pollen. In Ireland and Britain, the initial large-scale clearances are frequently associated with the Elm Decline. This phenomenon, observed across north-west Europe, involves a marked and rapid fall in elm (Ulmus) pollen representation and marks the boundary between the classic Atlantic and Subboreal pollen assemblage zones. Smith and Pilcher (1973) found that, within the limits of radiocarbon dating precision, the occurrence of the Elm Decline was by and large synchronous in Britain and Ireland. A more recent examination of 138 dates for the event emphasises the close timing of the decline throughout the two islands (Parker et al. 2002). Laminated lake sediments at Diss Mere, Norfolk, England, enabled Peglar (1993) to establish that the decline at this location took place in as little as six years. Long believed to be the outcome of selective clearance of elm by the first farmers, possibly for use as fodder (Troels-Smith 1960), the Elm Decline is now more commonly perceived as 523

the likely result of a pathogen akin to Dutch Elm Disease (Molloy and O’Connell 1987; Perry and Moore 1987). Support for this hypothesis has come from the identification of the remains of Scolytus scolytus L. beetles, one of the present day vectors of the pathogen, in mid-Holocene contexts in Britain (Girling and Greig 1985; Rasmussen 1993; Clark and Edwards 2004). The spread of the disease may have been facilitated by farming activities such as foddering or clearance, as the elm bark beetles are generally attracted to trees under stress (Clark and Edwards 2004). Indeed clearings in the forest may have been a prerequisite for the beetles’ penetration of primary, closed woodland (Parker et al. 2002). Climate change, too, may have played a role either directly by adversely affecting the flowering of elms (Parker et al. 2002) or by inducing stress in the trees (Clark and Edwards 2004), or indirectly by creating optimum conditions for the uptake of agriculture (Parker et al. 2002). Interestingly, recent research by Caseldine et al. (2005) on Achill Island, Co. Mayo, suggests that farming became established here during a prolonged period of dry conditions, which could indeed have facilitated a shift to agricultural regimes by extending the length of the growing season for cereals and fodder. A similar stimulus has been proposed for the spread of agriculture in Scotland and northern Europe (Bonsall et al. 2002). Aside from the issue of what caused the Elm Decline, increasing palynological evidence since the 1980s suggests that cereal farming both in Ireland and Britain may have first begun several centuries earlier than the archaeological evidence indicates (see Groenman-van Waateringe 1983; Williams 1989). These findings have sparked one of the hottest debates within the archaeological and palynological communities. Detecting reliable evidence for agriculture in

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the pollen record can be complicated. While reductions in tree cover and increases in ‘weed’ taxa typify human activity, other factors, such as tree-throws or intensive grazing by herbivore populations, can produce comparative pollen signals. Thus, only the identification of true cultivars provides dependable confirmation of human activity. The distinction of cereal pollen from that of wild grasses is based on grain measurements, pore diameter, annulus diameter and degree of protrusion and surface sculpturing (Beug 1961; Andersen 1979) and this in itself is problematical. Certain wild species, such as flote and marram grass, produce large pollen grains that morphologically overlap with cultivated varieties and ‘cereal-type’ pollen (i.e. grains that satisfy all the physical criteria for cereal pollen) have been reported from early Holocene contexts in Ireland and Britain, long before cultivated grasses could have reached these islands (O’Connell 1987; Tweddle et al. 2005). Furthermore, most cereals, with the exception of rye (Secale cereale), are self-pollinated and their pollen is not widely dispersed. Using modern pollen studies, Hall (1989b) has shown that the proportion of cereal pollen falls to less than 1% beyond 20 m from the arable field. The chances of cereal pollen reaching a typical palynological sampling site, possibly some distance from the nearest settlement or arable field especially if the sampling site is located at the centre of a large bog, are slim. Particularly high pollen counts (>1,000 grains) are needed if such scarce pollen is to be detected. Despite these issues, it has been argued that the coincidence of cereal-type and weed pollen with disturbances in woodland vegetation presents convincing evidence for an early establishment of farming in Ireland and Britain (Groenman-van Waateringe 1983; Edwards et al. 1986;

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Edwards and McIntosh 1988; Williams 1989). The earliest of these occurrences in Ireland is at Cashelkeelty, Co. Kerry, and dates to c. 4700 cal. BC, with a second episode at c. 4250 cal. BC (Lynch 1981). At present, the earliest independent dates for actual cereal remains from Irish archaeological sites fall around 3800 cal. BC (Hedges et al. 1989; Purcell 2002) and investigations at Neolithic sites continue to produce radiocarbon determinations that post-date 4100 cal. BC. These findings tend to reinforce the position that the pollen evidence for a ‘pioneer’ phase of agriculture is tenuous. However, the recovery of cattle bones, one of which was dated to c. 4350 cal. BC, at the Mesolithic site of Ferriter’s Cove, Co. Kerry (McCarthy 1999), now provides convincing evidence that some elements of farming had reached Ireland well before the ubiquitous appearance of manifestly Neolithic cultural material and sites across the island. Although the debate about the reliability of the pollen record for early agriculture in Ireland continues to rage, the domesticate animal remains from Ferriter’s Cove add weight to the case for an initial, unobtrusive farming phase and similar discoveries in the future may yet vindicate the palynological evidence. Given the preponderance of Neolithic megalithic tombs in the northern half of Ireland, it is intriguing to note that the first indications of domesticated animals and possibly plants are both to be found in the far south-west of the country.

Late Bronze Age Hillforts and their Economic Context

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Long considered to be an Iron Age phenomenon, Irish hillforts are increasingly yielding evidence for Late Bronze Age origins. In some instances (e.g. Downpatrick, Co. Down: Proudfoot 1954; 1956), the relationship of the occupation levels to the enclosing defences remains unclear, but at sites such as Haughey’s Fort, Co. Armagh (Mallory 1991; 1995), Rathgall, Co. Wicklow (Raftery 1976) and Mooghaun, Co. Clare (Grogan 1996), these features were clearly an aspect of the Later Bronze Age activity. The available dating evidence from several hillforts now indicates their emergence in the period between the late thirteenth and tenth centuries BC. What was the nature of activity at these sites? Are the often impressive ditch and bank constructions a symptom of an aggressive socio-political climate? Internal structural remains at Mooghaun include two-four house foundations, and the primary phase of occupation appears to have taken place towards the end of the tenth century cal. BC (Grogan 1996; 1999; 2005). Several houses were also recorded at Dún Aonghasa, Co. Galway (Cotter 1995; 1996). At Rathgall, extensive internal features include a large circular house, wicker-lined storage pits, a bronze-working area and cremation burials, illustrating a wide scope of activities at this site. The presence of large boulders within the ditches, however, apparently compromises the defensive character of the hillfort (Raftery 1976). Finds such as the remarkable composite glass and gold bead from Rathgall and bronze rings, gold beads and wire, and a disc-headed pin from Haughey’s Fort insinuate that these were sites of high status. Large caches of charred barley (Hordeum spp.) at Haughey’s Fort were free from chaff and weeds seeds, suggesting that they were processed elsewhere (Weir 1993a), and perhaps

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implying that the site was the focus of political or ritual tributes. A growing number of pollen records from the vicinity of hillforts add a new dimension to our understanding of the economic context of these sites. At Navan Fort (Emain Macha), Co. Armagh, a pollen profile from the adjacent lake of Loughnashade reveals substantial land clearance in this area beginning at 1409–1265 cal. BC, with increasing evidence for crop cultivation until c. 1000 cal. BC (Weir 1993a). Cereal caches from the nearby site of Haughey’s Fort corroborate the importance of arable crops at this time. At Loughnashade, however, a reduction in farming activity can be seen after 1000 cal. BC, and there appears to be a possible change in emphasis towards pastoralism. At approximately the same time as this shift, the pollen evidence from the inner ditch fill of Haughey’s Fort suggests abandonment of the site (Weir 1993a). Mooghaun hillfort also seems to have been associated with an extensive opening of the landscape from c. 1100 cal. BC and an intensification of activity after 1000 cal. BC during which total woodland clearance in the site’s catchment seems likely (Molloy 1997; O’Connell et al. 2001). High levels of cereal-type pollen indicate that arable agriculture was practiced. The agricultural phase comes to an end at c. 750 cal. BC with a rapid regeneration of woody vegetation. Interestingly, at Caherkine Lough located only 1.1 km to the east on the other side of a ridge, this phase of intensive agriculture is not evident (O’Connell et al. 2001), emphasising that the activity was concentrated in the vicinity of the hillfort. To the south-west of Mooghaun beyond the Shannon Estuary, Ballylin hillfort, Co. Limerick, is a large, trivallate enclosure

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and although undated, the site is comparable in construction to Mooghaun (Cody 1981). A pollen profile from Moyreen Bog, c. 7 km north-west of Ballylin, shows an intense phase of agricultural activity remarkably similar to that recorded at Mooghaun (Plunkett 1999; Fig. 12.6). The profile is dated by tephrochronology and the timing of the initial forest clearance is estimated to be c. 1200 cal. BC. Arable crops appear to have been more important in the earlier stages, followed by a shift to pastoralism after c. 1000 cal. BC. By 850 cal. BC, however, the activity subsides and woodland taxa become dominant. Could this phase of farming reflect activity associated with the Ballylin hillfort? If so, it suggests that the pollen record may be able to provide clues to the Late Bronze Age occupation of hillforts that have yet to be excavated. Certainly, the emerging pollen evidence seems to suggest that, whatever role the hillforts played, some of these sites at least were supported by a thriving, mixed farming economy that persisted for several centuries.

Agricultural Expansion in the Early Medieval Period Pollen diagrams from across Ireland show a remarkably similar pattern of woodland regeneration in the period between approximately 200 cal. BC and cal. AD 200, generally referred to as the ‘Late Iron Age lull’ in agriculture (Mitchell 1976). With few archaeological remains dating to this time, the lull has been considered symptomatic of reduced population pressure (Weir 1993a; 1993b; 1995). From approximately cal. AD 200–300, however, a resurgence of anthropogenic activity, frequently including the appearance

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of rye pollen, can be seen at many sites (e.g. Mitchell 1965; O’Connell et al. 1988; 2001; Hall 1990; Weir 1993a; 1995). At Loughnashade, Co. Armagh, unprecedented levels of cereal-type pollen feature from c. cal. AD 340 (Weir 1993a). The pollen records clearly demonstrate that the initiatives for these expansions pre-date the arrival of Christianity in the fifth century. Nevertheless, in many instances, these trends are amplified following the establishment of monastic centres throughout the island. At Lough Fark, Co. Mayo, woodland clearance begins c. cal. AD 400, with a notable increase in the presence of cereals after the founding of the nearby early Cistercian monastery of Mayo Abbey c. AD 670 (Fuller 2002). At Abbeyknockmoy, Co. Galway, initial anthropogenic activity is dated to c. cal. AD 450, with a further increase in agricultural indicators at cal. AD 700, well before the construction of the twelfth century monastery at this location (Lomas-Clarke and Barber 2004). At Mongan Bog, Co. Offaly, conversely, deforestation is not recorded until cal. AD 800, although the large monastic site located close by at Clonmacnoise was established in the mid-sixth century (Parkes and Mitchell 2000).

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Figure 12.6: Simplified pollen diagram from Moyen, Co. Limerick, showing an expansion of farming activity in the Late Bronze Age (Plunkett 1999). The Early Medieval agricultural boom observed in pollen records is not confined to monastic centres, however, and the increase in ringforts and crannogs from the sixth century has

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been seen as an indication of population expansion facilitated by an increase in farming output (Stout 1997). Indeed, the vegetation records from near such sites confirms the close relationship of the settlements and farming activity. The construction of a crannog at Ballywillin Lough, Co. Longford, c. cal. AD 650, for example, was preceded by a substantial reduction in surrounding woodland (Selby et al. 2005) and a pollen profile from next to Lios Lairthín Mór ringfort, Co. Clare, shows intense pastoral-based activity from about the same time (Jeličić and O’Connell 1992). The pollen evidence also refutes any suggestions that the intensification of cereal production is due to the introduction of new farming technology such as the mouldboard plough in probably the seventh century (Mitchell 1976). The same intensification, on the other hand, almost certainly warranted the construction of horizontal mills, indicative of large-scale cereal processing, that dendrochronological dating places mainly in the seventh to tenth centuries (Baillie 1995). Cereals were, of course, only one component of what faunal, plant macrofossil and documentary evidence show to have been a thriving, mixed economy in the Early Medieval period (see Kelly 1997), and the extensive forest clearances evident in pollen records through much of the island also reflect the large-scale establishment of pastures. The duration of activity varies from site to site, but there is no doubt that this period marks the first major stage in the widespread decline of Irish forests.

Conclusions The now largely deforested landscape of Ireland is the product of millennia of repeated human impacts on the environment. The abundant peat and lake deposits found

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throughout the island contain a history of those impacts recorded through the preservation of countless pollen grains that bear testimony to past vegetation cover and the ways in which anthropogenic interference has altered natural vegetation ecosystems. The pollen record has therefore played an important role in effectively documenting aspects of human settlement, economy and population dynamics that both complements and adds to our understanding of the archaeological record. Indeed, the pollen record has frequently stimulated important discussion and has on occasion provoked archaeologists to examine their perception of past human cultures. Considerable opportunities remain for both archaeologists and palynologists alike to integrate the two fields of study towards a more holistic reconstruction of former human interactions with the landscape. Research in pollen analysis has recently turned to the development of methods to assess quantitatively the nature and scale of past vegetation changes observed in the pollen record (e.g. Bröstrom 2002; Bunting 2003; Nielsen and Odgaard 2005). This has entailed the collection of data from modern and historical vegetation types to calibrate pollen assemblages with the surrounding landscape and to examine issues relating to pollen productivity and dispersal. A further important advance has been the development of computer models that predict the source areas and enable a more informed visualisation of past vegetation complexity (Middleton 2004). These initiatives, led by the Nordic Academy for Advanced Studies POLLANDCAL network are still at a developmental stage and require collaborations over wide areas, as the environmental variables affecting pollen production, plant communities and ultimately the fossil pollen record will not be uniform under varying climatic, edaphic

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and culture-influenced regimes. Such approaches present an exciting opportunity for palynologists to look at past landscapes from a new perspective.

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13 Alluvial Geoarchaeology in Ireland Anthony G. Brown, Gerard Aalbersberg, Martin Thorp and Peter Glanville

Abstract Due to its predominantly low relief and high rainfall a large proportion of the area of midland Ireland is characterised by a patchwork of lakes, raised mires and alluvial floodplains. This provides the potential for multi-proxy and multi-scale environmental reconstruction. The linkage of lakes, bogs and alluvial sequences has the potential to provide less equivocal information on key questions in Irish archaeology including; the transition from foraging to farming, regionality, ritual use of the landscape and climatic impact on prehistoric activity. This paper demonstrates the potential of this approach through several case-studies. These include studies of raised mire and alluvial data from the Little Brosna Valley in the middle Shannon Basin, the Liffey Basin in Co. Kildare and the Lee in Co. Cork. These, along with selected other studies illustrate both the relative lack of archaeological excavations in Irish floodplains and the potential that exists herein. The conclusion reached is that, despite a lack of geoarchaeological excavations, the geology and climate of Ireland has produced and preserved large areas of buried

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floodplain and alluvio-lacustrine landscapes and also provides an almost unique opportunity to compare alluvial geoarchaeology with other data sources pertinent to the making of the Irish landscape.

Introduction: The Geological and Geomorphological Context Ireland is a low, eroded landscape dominated by lakes, bogs and rivers. Its highest peak, Mount Carrentuohill in the Macgillycuddy’s Reeks, reaches only 1041 m above sea level, whilst the majority of the Irish landscape lies beneath 200 m above sea level. Geologically, Ireland is old, largely composed of Palaeozoic rock cut by Mesozoic and Tertiary palaeosurfaces upon which there is a discontinuous covering of Quaternary glaciogenic sediments. The hydrogeomorphic result is that most drainage is surficial, except on the limestone outliers, and, except on the mountain blocks, rivers are of low slope with Quaternary deposits being the most erodible sediments. Many of the lowland rivers are really glacially cut channels linking staircases of lakes which themselves are small remnants of earlier, much larger lake systems. The climate, which is oceanic and dominated by persistent low intensity rainfall, provides the ideal conditions for peat accumulation. Upland areas with more than 1250 mm rain per year carry blanket peat, whilst in the lowlands, hydromorphic and topographic basins often carry raised ombrogenous bogs. The result are rivers with high discharges per unit area, but with relatively un-flashy regimes, although peat-dominated catchments have moderately flashy regimes. Although the postglacial ecological and climatic changes will have been common to all Irish rivers, the response to such changes will have varied from catchment to catchment

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1. 2.

3.

4.

because of their great diversity in geomorphological properties (Glanville et al. 1997). On the basis of criteria such as rainfall and discharge, topography and stream power and the nature and availability of surface materials, it is possible to suggest there may be four broad classes of river basins in Ireland: Those of high rainfall and high power and low sediment availability, characterised by the western mountains and epitomised in Donegal. Those with moderate rainfall and moderate power, moderate to high sediment availability and characterised by upland and hilly areas of glacigenic sediments such as the Lee, Blackwater and Foyle. Those with moderate to low rainfall, low energy but moderate to high sediment availability characteristic of the glaciated lowlands and exemplified perhaps by the Suir, the Liffey and the Boyne. Those with moderate rainfall, low energy, negligible clastic sediment availability but with extensive mires and peatlands, such as the lower Shannon. Only Type (2) and (3) can be expected to contain alluvial records of environmental change and the accessibility of such records may be best in Type (3). A review of the Quaternary geology of Ireland has recently been provided by Coxon (2001). The key factor for Holocene alluvial development is the coverage of much of the island by unconsolidated, generally coarse sediments (sands and gravel) of glacial and glaciofluvial origin and a topography largely fashioned by the glacial processes of erosion, deposition and periglacial processes. These factors delimit the degrees of freedom of Irish fluvial systems and therefore their

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development since human arrival. When humans arrived in the Early Mesolithic, Ireland was largely forested and rivers would have been the main arteries of transport–indeed, they remained so until relatively recently. A variety of field methodologies have been employed in the studies reviewed in this paper, however, most follow standard geoarchaeological methodologies based on survey, coring and palaeoenvironmental analyses. Dates are quoted as in the original published text.

The History of Alluvial Studies in Ireland The first systematic observations on alluvial deposits can be traced back to the founding of the Geological Society of Ireland in 1831, the geological mapping by the father of Irish geology Richard Griffiths, and the activities of the Geological Survey of Britain and Ireland which had been founded in 1845. A persistent problem was the representation of both the solid and drift (Quaternary and Holocene) on one sheet (Herries-Davies 2001). Therefore Irish geology has always required an interest in the Quaternary and so it is unsurprising that Ireland has produced or attracted outstanding figures in the field of Quaternary Science such as Charlesworth, Farrington, Praeger, Jessen and G. F. Mitchell. Many of these scientists had an interest in archaeology and most particularly G. F. Mitchell (1912–1997), who combined these interests in his classic Reading of the Irish Landscape, first published in Ireland in 1986. In many ways G. F. Mitchell could be regarded as the father of Irish geoarchaeology, although in comparison to Britain, alluvial geomorphology has, until recently been an under-researched area; however, recent studies of river behaviour and alluvial stratigraphies include

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Croke (1991; 1994), Gallagher and Thorp (1995), Glanville et al. (1997) and Thorp and Gallagher (1999).

Lakes, Rivers, Bogs and Archaeology At the end of the Last Glacial period, Ireland presented a landscape of bare tundra mountains surrounded by marshy, deglaciated lowlands with moraines, eskers, outwash and meltwater complexes and often poorly integrated river systems. There were a large number of lakes of varying size, which had resulted from the impoundment of meltwater. Major lacustrine basins included Lough Boora-Ree, Lough Derg, Lough Erne and Lough Allen, Lough Gara, Sheelin, and Derravaragh in the Shannon system, as well as Lough Neagh in the north (Fig. 13.1). These large lake systems still existed when Ireland was occupied in the Early Mesolithic and would probably have been accessed by river. The shores of these lakes and rivers were of particular importance to Early Mesolithic forager-gatherer-hunters living in a largely wooded environment. Unsurprisingly, Mesolithic sites such as Mount Sandel, Co. Londonderry, detail the exploitation of freshwater resources such as salmon, trout, eels and even the seeds of the White Water Lily (Nymphae alba) (Woodman 1985). The greater aquatic dependency of the Irish Mesolithic is clearly a function of the lack of native mammals, including the Red Deer (Cervus elaphus). The distribution of sites of the Early Mesolithic type (Sandelian) shows a marked bias to major river valleys, lakes and the coast (then an inland cliff) with the densest concentrations around Lough Neagh and down the Bann Valley, the coast north of the Boyne Valley and along the Blackwater Valley in Co. Cork (Anderson 1993). There is little evidence to suggest this is a reflection of sampling bias and recent studies in Denmark have shown that differential sampling typically alters the absolute densities of 553

sites but not relative differences across the landscape (Odgaard and Rasmussen 2000). It would be more realistic to regard the geoarchaeological context of the Irish Early Mesolithic as alluvio-lacustrine in nature.

Figure 13.1: The major rivers of Ireland and the study areas discussed in the text. The boxes are the River Lee/ Gearagh study area (Brown et al. 1995), the Barrow (Zvelebil et al. 1996), the Shannon (Hooyer 1991; Vader 1993; Aalbersberg 1994) and the Liffey (Thorp and Glanville 1999). Sites of Later Mesolithic date, on the other hand, whilst still clustering around major valleys and lakes, appear to have been more widely dispersed. In a recent survey of the Lough

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Swilly region, Co. Donegal, Kimball (2000) notes a bias of Later Mesolithic sites towards estuarine and lowland floodplain ecozones. However, there remains a major visibility problem caused by the expansion of peatlands in the Middle Holocene (Littletonian period). Early landscapes are buried, such as the Neolithic field systems of Co. Mayo (Caulfield 1983), by expanding blanket bog and raised mires, and evidence of later activities entombed. This expansion of peatlands even constrained some rivers (see The Shannon System below) and thus the area of alluviation and so, although indirectly, influenced the location and local pattern of early farming. The oldest sites interstratified by alluvial sediments have been found to date from the Later Mesolithic-Early Neolithic (c. 6000–5000 cal. BC). Historical examples include the sites interstratified with diatomite in the Bann Valley excavated by Hallam Movius in the 1930s (cited in Mitchell and Ryan 2001). In the Neolithic, large lake systems linked by rivers still existed and travel may well still have been predominantly by water as illustrated by finds such as the 15 m long Lurgan logboat found in Addergoole Bog near Tuam, Co. Galway, in 1902 and now on display in the National Museum, Dublin. Recently there has been a re-evaluation of Irish linear monuments and the recognition of cursus-type monuments (Newman 1999). Cursus monuments appear to be particularly associated with river valleys and water, with terminations close to the river or tributary stream–a factor some have implicated in the interpretation of their meaning (Barclay and Hey 1999). The most striking Later Bronze Age and Iron Age aspect of alluvial environments appears to be the ritual deposition of artefacts and occasionally skulls in rivers as well as lakes. The record may be particularly rich for Ireland

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due to a relative lack of channel change in the Later Holocene (as discussed later). In the Early Christian era, both lake and larger riverine islands become favoured sites for ecclesiastical establishments including hermitages, chapels, monasteries and convents. This variable association with lakes and rivers provides intellectual justification for geoarchaeological studies.

Recent Palaeoenvironmental and Geoarchaeological Studies The Shannon System The Shannon is an unusual European river being a series of channels linking lakes (Fig. 13.2). Draining much of midland Ireland, and although only 205 km in length, the Shannon is the largest river in Ireland. The longest alluvial section, the Middle Shannon, connects Lough Ree to Lough Derg (60 km) and is characterised by a floodplain of bogs and seasonally flooded lands called callows (Heery 1993). The callows are of international importance for wildfowl, harbouring several endangered species including the Corncrake as well as 17 rare plant species (Heery 1993). This ecological heritage, along with its vulnerability has been recognised by the European Union (EEC-STEP Programme; Hooyer 1991; Vader 1993). This ecological value has originated through the interaction of natural alluvial hydrological and sedimentary processes and human activity. The channel of the Middle Shannon repeatedly bifurcates around alluvial islands–probably a residual element of an earlier multiple-channel (anastomosing) form. This is unsurprising given the extremely low slope and fine calibre sediment supply (Smith and Smith 1980; Nanson and Knighton 1996). Indeed, anastomosing channels seem to have been far more common

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in the lowlands of north-west Europe before Late Holocene alluviation and channel engineering (Brown 1997). On the valley floor are a number of raised (ombrotrophic) mires, some of which constrain the alluvial floodplain. Both the floodplain and bogs have developed in between several esker ridges orientated across the valley, especially well-developed south of Athlone. The bogs result from the low relief, ubiquity of glacial basins and high rainfall distributed throughout the year. The stratigraphy and developmental history of the callows has been revealed in a number of ditch sections and core transects. The general stratigraphy consists of basal sand and gravels of glaciofluvial origin, grey lacustrine silts and clay capped by a sand unit, white lake marls beneath peats and, in some areas especially close to the river, superficial units of clay, silt and fine sand. Detailed work in the Little Brosna Valley (Fig. 13.3) by Aalbersberg (1994) suggests the basal lake clays are of Late-Glacial age with the sand unit marking a sudden drop in lake level at the beginning of the Holocene. The white lake marl is highly calcareous containing abundant shells as well as ostracods, diatoms, Characeae (calcareous algae), insect and plant remains. The lakes were shallow and highly productive, although oligotrophic, due to a lack of nitrogen. The upper stratigraphy of the Little Brosna Valley, and large areas of the Shannon callows, shows hydroseral development with lakes being succeeded by reedswamp, sedge/fen, wet woodland and in some places Sphagnum dominated raised mire. Typical Brosna cross-sections reveal fine sands, silt and clay feathering out over the peat in the channel/levee zone. This stratigraphy reveals a high degree of channel stability during the period of peat growth and alluvial deposition. This alluviation is regarded by Aalbersberg (1994) as being the

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result of deforestation and cultivation in the catchment which contains the Slieve Bloom Mountains. In some places, such as Pollagh Bog on the Shannon, flood layers interdigitate with Sphagnum peat (Heery 1993). In other areas, the upper stratigraphy is locally variable, such as at Clonmacnoise where the peat accumulated to 3 m without evidence of alluviation, whilst only 9 km to the south at Bishops Islands the peat is covered by 1 m of silt and clay (Turbridy 1987). The stratigraphic work by Aalbersberg (1994) in the most downstream reaches of the Brosna has provided a chronology and record of environmental conditions during mire and floodplain development. He suggests that the shallow calcareous lake terrestrialised to Cladium-Phragmites swamp with a ‘diffuse’ multiple-channel river pattern around 6200 BP (5300–5000 cal. BC). Subsequently, secondary channels silted leaving a single channel system until a second phase of anastomisis began around cal. AD 1200 and a final contraction to a largely single channel system around cal. AD 1750 (Fig. 13.4). Palaeoecological analysis of Lusmagh Bog in the Brosna Valley reveals a phase of local burning prior to the elm decline after which occur the first large-scale anthropogenic impacts on the vegetation. The pollen diagram reveals a strong increase in herbs and some cereal-type pollen grains in zone BPLMBPZ-4, c. 4300–4150 BP (3100–2500 cal. BC). There is also abundant proxy-palaeoclimate data from the Brosna/Middle Shannon area. From Lusmagh Bog itself, there are five recurrence surfaces which Aalbersberg (1994) has correlated with the continental sequence (RYV-RYI) and in nearby Annagh Bog there are four recurrence surfaces (RYIV-RYI). Studies by Barber et al. (2003) at Mongan Bog near Clonmacnoise suggest the wettest period in the records occurred c. 2650 years BP (830–800 cal.

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BC) and c. 1000 BP (cal. AD 990–1030) with dry periods c. 5500 BP (4360–4260 cal. BC) and 1800 BP (cal. AD 130–320). The 830–800 cal. BC date may correspond with the Iron Age/Bronze Age (Subboreal/Subatlantic) climatic deterioration associated with reduced solar activity at the start of the so-called ‘Homeric Solar Minimum’ (van Geel et al. 1996). A site to the east of the Shannon catchment in the headwaters of the River Boyne, Carbury Bog, displays an abrupt appearance of the oceanic species Sphagnum imbricatum which has been dated by AMS wiggle matching at 850 cal. BC and also coincides with the sharp rise in δ14C (van Geel et al. 1998).

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Figure 13.2: Map of the Shannon catchment showing sites mentioned in the text (adapted from Hooyer 1991). The box is the study reach of the River Little Brosna (Aalbersberg 1994).

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Figure 13.3: A geomorphological map of the lower Little Brosna river valley (adapted from Aalbersberg 1994). The landscape archaeology of the Shannon Valley has, until recently, received less attention than its palaeoecology. Prehistoric structures, particularly barrows, occur on the alluvial callows, and occasionally on present and past alluvial 561

islands, as at Long Island near Clonown, a location that may have had special ceremonial significance (Brown 2004). In relation to prehistoric domestic archaeology, the potential of the area is illustrated by the excavations by the Irish Wetland Unit at Clonfinlough, Co. Offaly (Maloney et al. 1993; O’ Sullivan 1998). Clonfinlough was an enclosed farmstead built in wetlands on the south side of a small lake. It lies just to the east of the River Shannon, from which it is separated by an esker ridge upon which there is evidence of Bronze Age activity (O’Sullivan 1998). The site is palisaded with an associated trackway and was constructed between 917 and 899 BC (dendrochronology date). The site has excellent organic preservation and has yielded two boat paddles presumably for use on the Shannon. Recent excavations of the Clonmacnoise Bridge (O’Sullivan and Boland 2000) have dated its construction via dendrochronology to AD 840, making it the oldest recorded bridge in Ireland. Associated with the bridge were 11 dugout boats, axes, a copper-alloy basin and many other industrial and agricultural artefacts. The bridge was constructed of 50 oak posts fitted with base-plates to prevent further subsidence into the clay riverbed. Further analysis may reveal environmental details but it would appear that the location, width and depth of the river were similar in the ninth century as it is today. The historical stability of the planform of the Shannon (and probably other Irish lowland rivers) is probably due to the combination of low slope and therefore energy and high resistance from clay and peat riverbanks. The archaeological result is a continuity of landscape affording high potential for studies of alluvial landscape change due to a high probability of long-term preservation of artefacts and environmental records.

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Figure 13.4: Sumary didagram of the developmental phases and palaeoecological information from Lusmagh Bog. Little Brosna Valley (adapted from Aalbersberg 1994).

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Figure 13.5: A map of the Liffey catchment with sites mentioned in the text. The River Liffey The River Liffey, sourced in the north-west Wicklow Mountains and, flowing west, north and then east to Dublin, passes through at least four distinct reaches–in the mountains, the now flooded Blessington Basin, through the intensively farmed lowlands of Co. Kildare underlain by a complex of deglaciation tills and outwash sands and gravels, and finally the strongly urbanised reach from Leixlip to the sea (Fig. 13.5). In all reaches, save those above 300 m, settlement and agriculture have been almost continuous since Neolithic times, but of the river behaviour very little is known save for the Dublin city and the mountain reaches. The following account relates entirely to the mountain reach where the effects of environmental controls and human activities can, in part, be analysed. The 100 km2 upper River Liffey catchment, on the north-western side of the Wicklow Mountains, is defined by

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600–850 m encircling ridges. Long valley side slopes sweep smoothly down to narrow valley floors which lie at 220–350 m. The underlying granite rocks have provided the glacial till smearing the lower slopes and valley floors. Along the valley floors, the Post Glacial rivers have eroded a narrow pan-shaped trough countersunk 2–5 m into tills, moraines and outwash trains. This trough contains Holocene alluvial sediments which have been sourced mainly, but not entirely, from the glaciofluvial deposits. There are three sub-basins to the catchment wherein the valley floors are sufficiently wide to contain alluvial floodplains–the Coronation Plantation, the Ballydonnell and the Athdown Basins. Between these, the valley floor passes through gorge-like narrowings. Today, blanket peat covers the ridges and valley sides but in the lower part of the valley, where slopes are gentler and the till thicker, farmland and coniferous forests are extensive. Here and in the adjacent Blessington Basin there is some indirect archaeological evidence for Neolithic and Bronze Age settlement and more direct evidence for settlement from the Late Iron Age and onwards. Above 300 m in the upper basins, however, the harsh climate and small extent of mineral soils have always limited farming to several small areas.

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Figure 13.6: A schematic cross-section of the terraces of the River Liffey after Glanville et al. (1997). Pollen analysis (Glanville 1999) of blanket peats and peaty soils within the Holocene alluvial terraces show that the mountain catchment, between c. 7000 and 2000 cal. BC, was dominated by closed forests (initially oak, elm, pine then alder and birch) and that blanket peat did not begin extending until after 2000 cal. BC, although it had formed in wetter valley floor locations by 5000 cal. BC and on high plateaux by 7000 cal. BC. After 2000 cal. BC, the vegetation began changing as woodlands were opened up for agriculture, grasslands expanded, Ericaceae appeared and blanket peat began spreading downslope and thickening. Between 500 cal. BC and cal. AD 1000, a vegetation pattern not unlike the present day, but without the conifer plantations, had developed–small areas of birch, alder and oak woodlands and scrub, large areas of grasslands and pastoral agriculture with limited cereals, and extensive blanket peat on the upper slopes and on valley floor alluvia. ‘Intensive’ agriculture appears to have been located on the more freely draining tills and outwash deposits on the lower slopes in the Athdown Basin and on the limited alluvial terraces in the upper parts of the catchment. Stout (1994) has summarised what little is known of the archaeology in the north-west Wicklow Mountains. Whilst no evidence has been found in the upper part of the mountain catchment for pre-Medieval settlement, settlement of Neolithic and later date is suggested from the Athdown area and especially from the Blessington Basin reach of the Liffey. The most direct evidence for settlement in the mountain

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catchment, however, comprises ring forts of supposed Early Christian age in the Athdown Basin. In the valley floor widenings of the mountain reach there are two Holocene alluvial terraces flanking the current floodplain (Fig. 13.6; Glanville et al. 1997). These have been extensively dated using radiocarbon analysis and dendrochronology and by pollen spectra correlations with dates on pollen ‘master’ curves. The oldest terrace spans 5800–100 cal. BC whilst the younger is dated from c. 100 cal. BC–cal. AD 1600. Both terraces comprise several layers of sandy alluvium separated by palaeosols and the floodplains appear to have been constructed by episodic overbank flows and vertical accretion. Construction of the first floodplain was terminated by one or several major flood events c. 100 cal. BC when parts of the floodplain were stripped down to the underlying coarse gravel sheet that is present under all Holocene alluvia in the valley floors and when the river bed was scoured into this gravel by c. 5 m. Floodplain rebuilding over the wide, exposed gravel bars followed. A similar event or group of flow events terminated the second floodplain between c. cal. AD 1450 and 1800. Floodplains built post c. cal. AD 1600 comprise numerous thin laminae of coarse sand and peat laid down on a quasi-annual basis. This sedimentation style is associated with the onset of blanket peat gullying on the interfluves during the ‘Little Ice Age’ and of accelerated peat fuel cutting after c. cal. AD 1750 (Thorp and Gallagher 1999). Rates of sediment accumulation on the floodplains began to increase after c. 2000 cal. BC at an exponential rate, stabilising somewhat between cal. AD 400 and 1100 after which the rate dramatically increased. The initial increase in

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sedimentation rate seems roughly coeval with both the beginnings of vegetation modification by people and with climatically induced soil paludification and blanket peat expansion. Undoubtedly, the several sedimentation events that constructed the two floodplains were caused by rainfall-run-off events but the sediment yield may reflect, at least in part, an increasing access by run-off to soil and sediments induced by growing agricultural activity, both spatially and intensively, from the Bronze Age onwards. The two incision events, on the other hand, occurred when specific flood discharges exceeded the sedimentation–erosion threshold, a threshold which had itself been shifted by the increasing floodplain height. This was such that the next overtopping flow was so powerful as to have induced massive channel erosion rather than additional overbank sedimentation. The floods of ‘Hurricane Charlie’ in 1986 crossed analogous thresholds and produced similar effects to those of c. 100 cal. BC and c. cal. AD 1600–1800. Post cal. AD 1750, settlement and agricultural activity in the mountain reach of the Liffey has concentrated on the free draining gravel-dominated tills and outwash sediments veneering the lower hillside slopes and it may be reasonable to assume that previous farming generations made similar resource judgements; the terraces are generally devoid of signs of prehistoric settlements. However, in an exposure of the Mid-Holocene terrace at Kilbride, a circular hearth was seen with indications that it was used to fire crack blocks of vein quartz to make crude stone tools. Samples of the charcoal gave dates of 4043 and 3951 cal. BC, indicating a Neolithic age. The most extensive area of floodplain terrace surface is from the mid-Holocene in the Athdown Basin. However, soil paludification and hydromorphic peat

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development commenced on this surface c. 700 cal. BC and thereafter put this area beyond intensive use. In the upper part of the catchment the small terraces may have been mainly used for grazing although in the nineteenth century the mid-Holocene terrace was cultivated by the three farms which then existed there. It would appear that prehistoric settlement in the mountain Liffey catchment was not on the floodplains, which were of limited spatial extent and often wet, but on the adjacent well-drained valley footslopes. However, in the higher parts of the catchment in the areas marginal to settlement, the small floodplain terraces were perhaps the only sites for habitation. Enhanced sediment yields from cultivated and habited lower valley sides seem to have contributed to floodplain formation after c. 2000 cal. BC. It is difficult, however, to judge a discernable distinct effect upon run-off and river discharge of colonisation although it would be reasonable to assume run-off coefficients were enhanced by the reductions in vegetation bulk mass. There is some suggestion in the alluvial stratigraphies that the increase in sedimentation rate after c. 2000 cal. BC was caused mainly by increased frequency of overbank sedimentation events. This is certainly the case after c. cal. AD 500. The latter relates primarily to the development of peat erosion systems and to increased storm frequencies during the Little Ice Age but it is not clear what the relative roles of natural climate moistening and human created vegetation modifications were between those two periods.

The Lee Valley and the Gearagh

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The River Lee in south-west Ireland drains the Boggerach, Derrynasaggart and Shehy Mountains of west Cork (Fig. 13.7). Its source is a glacial lake at Gougane Barra and it flows 70 km to the sea at Cork through a series of reservoirs. Until 1954, a large tract of the floodplain upstream of Macroom was covered by a dense pattern of hundreds of wooded islands divided by small channels. This area of anastomosing river, called the Gearagh, was of international biological importance. A small surviving fragment has recently received attention from a bio-geomorphological perspective as it is one of the few wooded anastomosing reaches left in the British Isles and Ireland (Harwood and Brown 1993; Brown et al. 1995). More recent studies have also produced evidence of human activity in and around the floodplain. The upper Lee catchment is rich in standing archaeology with a dense cluster of wedge tombs (O’Brien 1993), stone rows and stone circles (Walsh 1993). The rows and circles are particularly common on the north side of the catchment and especially along the Foherish tributary. A stone circle sits on a spur of terrace gravels overlooking the Gearagh. Some palaeoenvironmental data is now available for this area. During the Late- Glacial, the River Lee bifurcated around a bedrock knoll in this reach leaving two tracts of outwash gravels. Only the most northerly of these tracts became the Holocene floodplain, whilst the southerly tract developed into raised mire. Pollen analysis of Annahala Bog, only 1 km from the Gearagh, reveals little or no signal of the alluvial woodland, probably due to the dominance of the mire and regional pollen signal. Stratigraphic investigations within the Gearagh have shown that the islands are typically composed of a felted organic-rich peat upon which lie the superficial sandy silt-clays (Fig. 13.8). Dating from two islands indicate that island formation began around the 570

thirteenth–fourteenth centuries AD and may have been caused by the confinement of the multi-channel river by a southerly flood embankment. More work is needed in order to define the relationship between channel alterations, land use change and the geomorphological development of the River Lee.

Figure 13.7: A map of the upper Lee catchment showing archaeological sites and the location of the Gearagh.

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Figure 13.8: Stratigraphic sections across islands in the Gearagh. Other Alluvial-related Studies Interdisciplinary studies in the Barrow Valley, south-east Ireland, have been aimed at reevaluating the so-called Riverford Culture (Zvelebil et al. 1996). Stratigraphic studies, particularly in the Athy Basin (Fig. 13.9) have revealed two periods of widespread alluviation, the first in the Early Holocene c. 8000–6000 cal. BC and the second after c. 2000 cal. BC. The dominant controls on the later period are not clear although based on earlier radiocarbon dating of an oak,

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Mitchell (1986) had speculated that Bronze Age farming could be implicated. However, as Zvelebil et al. (1996) point out c. 2000 cal. BC is also a period of climatic deterioration in Ireland and Britain. Adjacent studies of raised mire records could be used to explore these factors further. The study also has a strong taphonomic aspect revealing how the distribution of Mesolithic and Neolithic flints is biased by the sedimentation history of the basin. Another illustration of the alluvial geoarchaeological potential in Ireland can be taken from the prehistoric monumental complex in the Boyne Valley. The Neolithic monuments of Newgrange, Knowth and Dowth are some of the most researched sites in Ireland. Studies have also expanded to include the surrounding landscape (e.g. satellite tombs). Cooney (2000) uses the indications from on-site pollen and seed studies and the character of the local area (topography, soils etc.) to produce a hypothetical land use map. There are also monuments on the valley floor (e.g. satellite tombs and a henge) and both the topography and aerial photographs suggest a palaeochannel to the north of these sites and the present channel. The use of palaeochannels for deriving local land use and land management data has been neglected in Ireland almost certainly because of the wealth of potential sites from raised mires. However, the palaeo-data that maybe derived from palaeochannels, although of local origin, is almost certainly more sensitive to clearance, management and farming on the floodplain, terraces and surrounding slopes and hence more valuable at the spatial scale of landscape archaeology (Brown 1999). The Irish Discovery Programme’s current Lake Settlement Project will hopefully go some way towards exploiting this alluvial potential as many lake sites are located at the junction of rivers with lakes, or in or by

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lakes which exist within alluvial landscapes (see Whitehouse, this volume). An example of such an area is Lough Derravarragh, Co. Westmeath, where excavations and exposures at Clonava 1 have revealed Neolithic chert-knapping (Mitchell 1972; Woodman 1978). The landscape:

Figure 13.9: An annotated cross-section of the Athy Basin of the Barrow Valley (adapted from Zvelebil et al. 1996).

‘was a stretch of fen beside the lake, which had been dissected by numerous channels as the river Inny entered Lough Derravarragh’ (O’Sullivan 1998, 49). Mesolithic scatters have also been found at Clonava which, during the Mesolithic, was a large island surrounded by a large area of wetlands. Indeed there appears to be a bias to the location of Mesolithic finds towards lake islands, promontories and lake-river junctions. Whilst these locations offer both good visibility and a variety of resources they are also the most accessible by boat. The use of islands is particularly significant and geoarchaeology has considerable potential in relation to the identification, delimitation and 574

characterisation of past alluvial, alluvio-lacustrine and lacustrine islands. This is not simply a contextual matter as it has been argued that the location of some types of archaeological sites on islands, particularly Early Christian sites, may have far more than functional significance (Brown 2004). Most upland rivers in Ireland are small and apart from the Liffey have received little geomorphic attention. However, some work has been done on the alluvial fans of the Macgillyguddy’s Reeks in south-west Ireland by Anderson et al. (2000). Radiocarbon dating shows episodic Holocene aggradation and incision with aggradation clustering into two periods, cal. AD 230–790 and cal. AD 1510–present. The authors correlate these phases with enhanced valley alluviation in northern England implying an overall climatic control. However, they also report that pollen analysis of peats interbedded in the fans indicate that land use change (probably overgrazing) may have been important in reducing the threshold of slope stability and so increasing aggradation during intense rainstorms.

Conclusions: The Archaeology of River Valleys and Geoarchaeological Potential The alluvial geoarchaeology of Ireland has yet to be seriously evaluated. However, the potential is high in the lowlands with a dominance of vertical sedimentation and bog development over erosion and fluvial reworking. The low-energy environments of most Irish floodplains have almost certainly entombed abundant evidence of alluvial landscape change, which awaits excavation. There are, however, obvious problems concerning high water-tables, but there are also unique opportunities through the combination and linkage of

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alluvial, lacustrine and mire based records of environmental change and the human creation of the Irish landscape. This endeavour need not be seen as entirely empirically driven as serious archaeological questions may be tackled including the location and nature of early prehistoric activity and mobility, the role of water in later prehistory and the relative role of human activity and climate in both peat growth and erosion, and in alluviation.

References Aalbersberg, G. 1994. The Little Brosna River Valley: Quaternary Geology and Palaeo-ecology. Unpublished M.Sc. Dissertation, Free University, Amsterdam, 2 vols. Anderson, E. 1993. The Mesolithic: fishing for answers, pp. 16–24 in Twohig, E. S. and Ronayne, M. (eds.), Past Perceptions: The Prehistoric Archaeology of South-West Ireland. Cork: Cork University Press. Anderson, E., Harrison, S., Passmore, D. G. and Mighall, T. M. 2000. Holocene alluvial-fan development in the Macgillycuddy’s Reeks, southwest Ireland. Geological Society of America Bulletin 112, 1834–49. Barber, K. E., Chambers, F. M. and Maddy, D. 2003. Holocene palaeoclimates from peat stratigraphy: macrofossil proxy-climate records from three oceanic raised bogs in England and Ireland. Quaternary Science Reviews 22, 521–39. Barclay, A. and Hey, G. 1999. Cattle, cursus monuments and the river: the development of ritual and domestic landscapes in the Upper Thames Valley, pp. 67–76 in Barclay, A. and Harding, J. (eds.), Pathways and Ceremonies: The Cursus

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Monuments of Britain and Ireland. (Neolithic Studies Group Seminar Paper No. 4). Oxford: Oxbow. Brown, A. G. 1997. Alluvial Geoarchaeology. Cambridge: Cambridge University Press. Brown, A. G. 1999. Characterising prehistoric lowland environments using local pollen assemblages. Quaternary Proceedings 7, 585–94. Brown, A. G. 2004. Divisions of floodplain space and sites on riverine ‘islands’: functional, ritual, social, or liminal places? Journal of Wetland Archaeology 3, 3–16. Brown, A. G., Stone, P. and Harwood, K. 1995. The Biogeomorphology of a Wooded Anastomosing River: The Gearagh on the River Lee in County Cork, Ireland (Occasional Papers in Geography No. 32). Leicester: University of Leicester. Caulfield, S. 1983. The Neolithic settlement of north Connaught, pp. 195–215 in Reeves-Smith, T. and Hamond, F. (eds.), Landscape Archaeology in Ireland (BAR British Series 116). Oxford: British Archaeological Reports. Cooney, G. 2000. Landscapes of Neolithic Ireland. London: Routledge. Coxon, P. 2001. Cenozoic: Tertiary and Quaternary (until 10,000 years before present), pp. 387–428 in Holland, C. H. (ed.), The Geology of Ireland. Dunedin: Dunedin Academic Press. Croke, J. C. 1991. Floodplain variability in the Glenmalur valley, South East Leinster, Ireland. Unpublished Ph.D.

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Thesis, University College Dublin, National University of Ireland. Croke, J. C. 1994. Floodplain change in the Glenmalure valley, southeast Leinster. Irish Geography 27, 122–34. Gallagher, C. and Thorp, M. B. 1995. The fluvial concentrations of heavy minerals in the Slieve Bloom Mountains, Central Ireland. Irish Geography 28, 14–34. Glanville, W. P. 1999. Holocene River Behaviour and Environmental Change in the upper river Liffey Catchment, Co. Wicklow, Ireland. Unpublished Ph.D. thesis, University College Dublin, National University of Ireland. Glanville, W. P., Thorp, M. B. and Gallagher, C. 1997. River change during the late Quaternary in the Upper Liffey, pp. 133–41, in Sweeney, J. (ed.), Global Change and the Irish Environment. Dublin: Royal Irish Academy. Harwood, K. and Brown, A. G. 1993. Changing in-channel and overbank flood velocity distributions and the morphology of forested multiple channel (anastomosing) systems. Earth Surface Processes and Landforms 18, 741–48. Heery, S. 1993. The Shannon Floodlands; A Natural History. Newtownlynch: Tír Eolas. Herries-Davies, G. L. 2001. History of Irish geology, pp. 493–504 in Holland, C. H. (ed.), The Geology of Ireland. Dunedin: Dunedin Academic Press. Hooyer, A. 1991. Introduction to the Middle Shannon Catchment, Ireland (EEC-STEP Project Report 11/1). Amsterdam: Amsterdam Free University.

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Kimball, M. J. 2000. Variation and context: ecology and social evolution in Ireland’s later Mesolithic, pp. 31–48 in Desmond, A., Johnson, G., McCarthy, M., Sheehan J. and Twohig, E. S. (eds.), New Agendas in Irish Prehistory. Bray: Wordwell. Maloney, A., Jennings, D., Keane, M., MacDermott, C. 1993. Excavations at Clonfinlough, Co Offaly (Irish Archaeological Unit Transactions No. 2). Dublin: Irish Archaeological Unit. Mitchell, G. F. 1972. Some ultimate Larnian sites at Lake Derryvarragh, Co. Westmeath. Journal of the Royal Society of Antiquaries of Ireland 102, 160–73. Mitchell, G. F. 1986. The Irish Landscape. Dublin: Country House. Mitchell, G. F. and Ryan, M. 2001. Reading the Irish Landscape. Dublin: Town House. Nanson, G. C. and Knighton, A. D. 1996. Anabranching rivers: their cause, character and classification. Earth Surface Processes and Landforms 21, 217–39. Newman, C. 1999. Notes on four cursus-like monuments in County Meath, Ireland, pp. 141–47 in Barclay A. and Harding J. (eds.), Pathways and Ceremonies: the Cursus Monuments of Britain and Ireland (Neolithic Studies Group Seminar Paper No. 4). Oxford: Oxbow. Odgaard, B. V. and Rasmussen, P. 2000. Origin and temporal development of macro-scale vegetation patterns in the cultural landscape of Denmark. Journal of Ecology 88, 733–48.

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O’Brien, W. 1993. Aspects of wedge tomb chronology, pp. 63–74 in Twohig, E. S. and Ronayne, M. (eds.), Past Perceptions: The Prehistoric Archaeology of South-West Ireland. Cork: Cork University Press. O’Sullivan, A. 1998. The Archaeology of Lake Settlement in Ireland (Discovery Programme Monograph 4). Dublin: Royal Irish Academy. O’Sullivan, A. and Boland, D. 2000. The Clonmacnoise Bridge: An Early Medieval River Crossing in County Offaly (Archaeology Ireland Heritage Guide 11). Bray: Wordwell. Smith, D. G. and Smith, N. D. 1980. Sedimentation in anastomosing river systems: examples from alluvial valleys near Banff, Alberta. Journal of Sedimentary Petrology 50, 157–64. Stout, G. S. 1994. Wicklow’s Prehistoric Landscape, pp. 1–40 in Hannigan, K. and Nolan, W. (eds.), Wicklow: History and Society. Dublin: Geography Publications. Thorp, M. B. and Gallagher C. 1999. Dating recent alluvial sediments in the Wicklow Mountains. Irish Geography 32, 112–25. Turbridy, M. 1987. Clonmacnoise Heritage Zone Project. A Portfolio of Management Plans. (Unpublished final Report to EEC). Dublin: Trinity College. van Geel, B., Buurman, J. and Waterbolk, H. T. 1996. Archaeological and palaeoecological indications of an abrupt climate change in the Netherlands, and evidence for climatological teleconnections around 2650 BP. Journal of Quaternary Science 11, 451–60.

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van Geel, B., van der Plicht, J., Kilian, M. R., Klaver, E. R., Kouwenberg, J. H. M., Rensses, H., Reynaud-Farrera, I. and Waterbolk, H. T. 1998. The sharp rise of δ14C c. 800 cal BC: possible causes, related climatic teleconnections and the impact on human environments. Radiocarbon 40, 535–50. Vader, L. 1993. Hydrological Characterisation of the Little Brosna Floodplain, Ireland (Report EEC-STEP Project). Amsterdam: Amsterdam Free University. Walsh, P. 1993. In circle and row: Bronze Age ceremonial monuments, pp. 101–13 in Twohig, E. S. and Ronayne, M. (eds.), Past Perceptions: The Prehistoric Archaeology of South-West Ireland. Cork: Cork University Press. Woodman, P. C. 1978. The Mesolithic in Ireland: Hunter-gatherers in an Insular Environment (BAR International Series 58). Oxford: British Archaeological Reports. Woodman, P.C. 1985. Excavations at Mount Sandel 1973–77 (Northern Ireland Archaeological Monograph 2). Belfast: HMSO. Zvelebil, M., Macklin, M. G., Passmore, D. G. and Ramsden, P. 1996. Alluvial archaeology in the Barrow Valley, southeast Ireland: the ‘Riverford’ culture revisited. Journal of Irish Archaeology 7, 13–40.

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Acknowledgements The authors must thank several researchers for assisting in the collation of information including M. Macklin, A. O’Sullivan, K. Barber and P. Hughes. We must also thank S. Roullard for drawing several of the diagrams.

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14 Multi-proxy Approaches to Palaeohydrological Investigations of Raised Bogs in Ireland: A Case Study from Derryville, Co. Tipperary Christopher J. Caseldine and Benjamin R. Gearey

Abstract The analysis of palaeohydrological sequences from raised (ombrotrophic) mires for palaeoclimatic reconstruction is discussed. Previous palaeohydrological study in Ireland is outlined and the lack of attempts to link such investigations to archaeological sequences highlighted. The strengths and weaknesses of the four main palaeohydrological proxy techniques of plant macrofossil, peat humification determinations and testate-amoebae analyses are discussed. Palaeohydrological studies undertaken as part of integrated archaeological and environmental investigations at Derryville Bog, Co. Tipperary, are introduced and the results of multi-proxy analyses from one peat sequence (DER18) presented. The patterns of wet-dry shifts between 2270 cal. BC and cal. AD 80 as inferred from the proxies are compared and contrasted. It is concluded that the different proxies tend to show similar patterns although there are discrepancies in 583

the timing and magnitude of palaeohydrological change. The results from Derryville suggest that the development of the bog appears to have been driven largely by autogenic (internal) rather than allogenic (e.g. climate) factors. The need for further, multi-proxy palaeohydrological study is stressed and the context this can provide for wetland archaeological sites highlighted.

Introduction: Raised Bogs, Palaeohydrology and Climate Change Research over at least the last three decades has demonstrated that raised mires can provide detailed records of changes in Holocene palaeoclimate (e.g. Aaby 1976; Barber 1981; 1982; Barber et al. 1994; 1998; Chambers et al. 1997; Chambers and Charman 2004; Charman et al. 1999; Hendon et al. 2001). This is based on the premise of a direct coupling of the surface wetness of ombrotrophic systems to the atmosphere via the precipitation/evaporation ratio. Quantification of such palaeohydrological changes in raised mire stratigraphy has been approached mainly through the application of the analysis of peat humification, plant macrofossils and testate amoebae. Recent work utilising these proxy indicators at a range of sites in north-west Europe suggests a strong degree of synchroneity between certain periods of increased wetness over the Mid- to Late Holocene in particular (e.g. Chambers et al. 1997; Hughes et al. 2000b; Charman et al. 2001; Hendon et al. 2001; Langdon and Barber 2001; Mauquoy et al. 2004). It is hypothesised that certain of these phases correlate with climatic shifts as identified through the analyses of other records including the Greenland Ice cores (O’Brien et al. 1995), tree line and tree ring studies (e.g. Baillie and Munroe 1988; Gear and Huntley 1991), lake level

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and sedimentation data (e.g. Yu and Harrison 1995) and historical sources (Lamb 1977). The relationship between peat stratigraphy and climatic change is far from straightforward with the relative significance of temperature and precipitation in driving changes in surface wetness currently uncertain. The causes of ‘sub-Milankovitch’ scale climatic changes remain relatively poorly understood although it is hypothesised that in north-west Europe at least, such changes may be linked to shifts in ocean circulation (Barber et al. 1994; Andersen et al. 1998). Recent research by Charman et al. (2001) has, however, suggested that the peat record may be more strongly influenced by precipitation than by temperature changes. Establishing palaeohydrological changes in raised mires is not only significant in the context of identifying climate change. Discerning shifts in the hydrological status of such systems, whether autogenic or allogenic, is also important in terms of defining and understanding episodes of human exploitation of raised mires, since such activity may directly affect access on to and across mire surfaces. This is especially significant in the Irish context where ombrotrophic bog covers such large areas of the landscape and archaeological remains in raised mires tend to be much more common than in England (see Raftery 1996). Some areas of raised mire contain considerably higher densities of archaeological remains than others and the respective role of cultural and environmental factors in these distributions has been little researched. If frameworks of environmental change can be established reliably for particular raised mire systems, this will assist in the formulation of hypotheses regarding the possible interplay between environmental, cultural and economic factors in the

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distribution of such archaeological sequences (see Gearey and Chapman 2004; Gearey and Caseldine 2006).

Previous Palaeohydrological Research in Ireland Only a relatively limited number of investigations of the palaeohydrology of Irish peatlands have been carried out in the last two decades. Van Geel and Middledorp (1988) analysed fungal spores and macrofossils from a sequence from Carbury Bog, Co. Kildare, covering the last c. 1000 years. They demonstrated that Sphagnum imbricatum disappeared from the bog at c. cal. AD 1400 to be replaced by S. magellanicum, concluding that this was due to atmospheric pollution. This study also included an investigation of the 2 1 H/ H ratio of peat samples, on the basis that the cellulose of raised bog plants directly reflects the isotope composition of the rainwater. This aspect of the research demonstrated that although the ratios are strongly related to local changes in species composition of the peat, the use of such measurements as a palaeoclimatic proxy is beset with difficulties. Van der Molen and Hoekstra (1988) undertook pollen, sporeand macrofossil- based analysis of a 0.4 gm long peat sequence from Woodfield Bog, near Clara Bog, Co. Offaly, and concluded that hummock-hollow complexes at this site reacted to fluctuations in rainfall rather than temperature. The study also demonstrated that decomposition rates varied between Sphagnum species, with Sphagna Section Acutifolia more resistant to decay than Sphagna Section Cuspidata. Van der Molen et al. (1992) also carried out detailed investigations focussing mainly on the contemporary hydrology, chemistry and vegetation of hummock-hollow complexes at Clara Bog.

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Blackford and Chambers (1991; 1995) carried out humification analyses on a sequence from the blanket mire of Letterfrack Bog, Connemara. An increase in surface wetness was identified at this location at around cal. AD 550–740, and suggested that this could be correlated with similar wet shifts at other sampling sites in the British Isles reflecting a ‘Dark Age’ climatic deterioration. Barber et al. (1994; 2000) studied Late Holocene macrofossil sequences from Abbeyknockmoy Bog, Co. Galway, and Mongan Bog, Co. Offaly, as part of a general investigation of peat stratigraphy and climate change although the details from these sites are not reported on in detail. Work undertaken at Corlea, Co. Longford (Casparie and Moloney 1996), revealed a complex interaction between peat growth and trackway development, laying the foundations for future studies of the relationship between archaeology and peat character within Irish raised bog systems. Until recently, no detailed investigation or comparison of the applicability of different techniques for palaeohydrological reconstruction had been attempted in Ireland. This paper will present a case study from an ombrotrophic mire in Co. Tipperary (Fig. 14.1), which formed a component of multi-disciplinary research carried out during the archaeological excavations of Derryville Bog under the auspices of the Lisheen Archaeological Project (Cross et al. 2001; Gowen et al. 2005). The palaeohydrological analyses were carried out as part of the palaeoecological programme (full details of which are available in Caseldine et al. 2005), which was closely integrated with the extensive archaeological and detailed peat stratigraphical investigations (Casparie 2005).

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A total of seven sequences were investigated from across the mire. This paper will consider the results of the analyses from only one of these sequences to illustrate the use of testate amoebae, humification and plant macrofossil remains in the reconstruction of changes in surface wetness for ombrotrophic mires. The potential and also the problems associated with the respective techniques will be considered. The following section will briefly describe and assess the three main proxy methods used for palaeohydrological investigations with implications for future archaeological contexts.

Figure 14.1: Location of Derryville Bog, Co. Tipperary. See Figure 14.2 for detail of the study area.

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Proxy Methods for Palaeohydrological Reconstruction Plant Macrofossils Macrofossil assemblages from ombrotrophic mires have proved a valuable resource for the reconstruction of palaeohydrological changes in peatlands (e.g. Barber 1982; Barber et al. 1994). Sphagnum species, the major peat forming taxa in ombrotrophic systems, have habitat preferences that are strongly related to the height of the water table (e.g. Ivanov 1981). Sphagnum Section Cuspidata and Subsecunda, for example, are typical of very wet habitats with the former often found in pools, whilst Sphagnum Section Acutifolia is common in drier habitats such as hummocks. Other components identified in the macrofossil record from raised mires can include other bryophytes, monocotyledons, usually undifferentiated sedges and grasses although Eriophorum spp. (cotton grass) may be easily recognised as a separate group of the sedges, Ericaceae (heathers) and other woody remains. These taxa can also provide information relating to hydrology. Reconstruction based on macrofossils can either be fairly simple and approached through a subjective assessment of the relative moisture preferences of different taxa (e.g. Sphagnum–wet, Calluna– dry) or can use a ‘training set’ approach that applies detailed knowledge of the modern mire ecology to produce a statistical transfer function. Probably the best-known approach of this type is that of Dupont (1986), who assigned a ‘weight’ to different Sphagnum species ‘… a certain arbitrary value that is used to separate ecologically different species groups’ (van der Molen and Hoekstra 1988, 22). These values can then be applied to sub-fossil 589

assemblages to produce a reconstruction of wet-dry shifts across time. Another approach is to utilise axis scores as determined through Detrended Correspondence Analysis (DCA) (Barber et al. 1994). However, as Charman et al. (1999, 452) observe: ‘… both these approaches are likely to give non-linear scales and it is therefore difficult to compare the magnitude of events at different points on the scale’. Other complicating factors include the differential decay of Sphagnum species alluded to above (Johnson and Damman 1991) and the lack of modern analogue sites for Sphagnum imbricatum, a species frequently encountered in the sub-fossil record but currently extinct on Irish and British peatlands (Stoneman 1993; Stoneman et al. 1993).

Humification Humification is a measure of the degree of decay of peat. The wetter/colder the conditions the peat accumulates under (i.e. more anaerobic), the less decay the peat-forming vegetation will undergo, with a drier/warmer environment resulting in increased decay. Estimations of humification can thus be used as a proxy measure of changes in hydrology (e.g. Aaby 1976; Chambers 1984; Blackford 1993; Blackford and Chambers 1993). A range of measures have been devised to quantify the extent of humification, including visual estimates of the breakdown of the constituents of the peat through to the colour or turbidity of water extracted from peat samples. More recently, techniques have sought to extract the humic and fulvic acids (produced by the decay processes of plant matter) from peat and to estimate the concentration of these as a measure of the degree of decay (Blackford and Chambers 1991). One of the main problems with the interpretation of

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humification records is that the scale is non-uniform through time and it is therefore difficult to compare different segments of the same record in terms of ‘… absolute magnitude of events’ (Charman et al. 1999, 452). Furthermore, recent work has shown that the underlying assumptions behind humification analyses, the relative proportions of the humic, fulvic and other acids being measured, are open to question (Caseldine et al. 2000). Despite the limitations of this technique, it remains a relatively simple and apparently effective way of identifying change within peat sequences, whereby detrended sequences of wetness/dryness shifts can be identified, albeit in a highly qualitative way.

Testate Amoebae Testate amoebae are Protozoa, which are commonly found in moist and freshwater environments including standing water, soils, mosses and peats. The shells (‘tests’) of these amoebae are preserved in anaerobic environments following their occupants’ deaths and may be recovered and concentrated for identification, which is often possible to species level (Charman et al. 2000). The relationship between testate faunas and micro-environmental factors, with moisture levels in particular being significant, has been known for some time (e.g. Heal 1962; Meisterfeld 1977) and has been used in the past to infer changes in the moisture status of peatlands (Tolonen 1986). Recent studies of modern populations have demonstrated that depth to local water table and percentage soil moisture are major environmental variables that control the composition of testate communities (Woodland et al. 1998). Such research has led to the creation of transfer functions based on these modern analogues that may be

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applied to sub-fossil assemblages to allow the quantitative reconstruction of water-table changes in raised mire systems (Warner and Charman 1994; Charman et al. 1999; Charman et al. 2001; Hendon et al. 2001). There are some problems with the application of such transfer functions including the lack of modern analogues for some assemblages encountered in the sub-fossil record, variability in preservation through deposits and sequences (Charman et al. 2001), and the possible influence of factors other than moisture on population changes. However, there is no doubt that analysis of testate amoebae offer a potentially more quantitative alternative to other methods.

Case Study: Palaeohydrological Investigations at Lisheen, Co. Tipperary–Palaeohydrological Changes around the Bronze Age Causeway, Killoran 18 Introduction The site of Derryville Bog (Fig. 14.1) is located in the Irish midlands, in north Co. Tipperary. It is part of the 60 km long Littleton Bog complex (Mitchell 1965) and forms a c. 600 m wide north-south tongue of bog at the county boundaries of Tipperary, Laois and Kilkenny. The Lisheen Archaeological Project undertaken by Margaret Gowen and Co. Ltd. investigated a total of 66 archaeological sites in an area of around one square kilometre of this wetland (Gowen et al. 2005) (Fig. 14.2). Associated palaeoecological investigations were concerned with seven sediment sequences from the same area (see Caseldine et al. 2005; Caseldine and Gearey 2006). The sequence (DER18) that is the subject of this paper was sampled from Field 41 (Fig. 14.2) through the line of

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Killoran 18, a Bronze Age causeway that was constructed to cross the mire (see Cross May et al. 2005a; 2005b). This location was apparently selected as suitable for a crossing point as it was a drier area of reed fen peat situated on a watershed between the two cupolas of raised bog growth. The trackway is some 520 m long and is distinguished by the use of stone in its construction, except for a 50 m stretch at the western end where brushwood was used. The level of the trackway in the sampled sequence is dated to between 1640 cal. BC and 1440 cal. BC, based on both dendrochronological and radiocarbon ages from trackway timbers.

Figure 14.2: The Derryville Bog study area, showing selected archaeological sites and palaeoenvironmental sampling sites.

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The area of the mire is that which existed in the Iron Age. The trackway is identified as ‘Killoran 18’ and the palaeohydrological sequence discussed in this paper is from the location marked ‘DER 18 (East)’. Methods A section incorporating the causeway was sampled using steel monolith tins measuring 50x10x10 cm. The sample was wrapped in tin foil and stored at 4°C. The stratigraphy is shown in Figure 14.3, alongside the palaeoecological diagram. The basal 0.65 m consisted of fen peat with abundant monocotyledonous remains including Phragmites and some woody detritus identified as Alnus. The uppermost 0.85 m consisted of highly humified Sphagnum peat. Samples were extracted from the sequence at 2 cm intervals for preparation for testate amoebae, humification analyses and macrofossils. In addition, samples were also analysed palynologically using standard techniques (Moore et al. 1991), with a minimum of 500 Total Land Pollen counted for each sample (Caseldine et al. 2005). Samples for radiocarbon dating were submitted to Beta Analytic, Miami, Florida. Testate amoebae extraction followed standard procedures (Hendon and Charman 1997) involving the boiling of 1 cm3 peat in distilled water to disaggregate the sediment, followed by microsieving (at 355 mm) and backsieving (10 mm). The samples were then concentrated via centrifuging and mounted on slides in glycerol and counted at a magnification of x 400. Taxonomy follows Charman et al. (2000).

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Figure 14.3: Palaeohyddrological Diagram–DRE18.

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Macrofossil analyses were carried out on the material retained on the 355 mm sieve following testate extraction. The sample was scanned under a binocular microscope and the relative composition estimated based on a simple 5-point scale (cf. Barber 1981), ranging from 1 (rare) to 5 (abundant). Five main groups were recognised: Sphagna-branch and stem leaves; wood remains, Ericaceous remains (typically rootlets) and Eriophorum vaginatum, usually in the form of densely tufted masses with spindles from the leaf bases. If present, up to 50 Sphagnum leaves were picked out and mounted in glycerol for identification to species or family group with the aid of the key by Daniels and Eddy (1990) using an Olympus BH-2 microscope. Monocotyledons and Ericaceae are generally taken to indicate relatively dry conditions in comparison to Sphagna, although some species or species groups may be indicative of wet conditions. This problem may be partially overcome by comparison of the macrofossil with the palynological record (see below). Other studies of macrofossils from raised mires have used larger sample sizes (typically 125 cm3) and more sophisticated methods for estimation and identification of vegetative remains (e.g. Hughes et al. 2000a; 2000b). However, the use of samples from which the testate faunas had been extracted meant that these assemblages were directly related to micro-environmental conditions as inferred from the macrofossils, allowing a more precise comparison of the two proxies. Humification determinations followed the standard method described by Blackford and Chambers (1993) which involved the extraction of the insoluble residues from a known weight of dried peat by boiling the sample in sodium hydroxide

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(NaOH). The resultant solutions were measured by the percentage of light transmitted through the extract at 540 nm (nanometers) using a Unicam 5625 UV/VIS Spectrometer, with increased light penetration assumed to reflect reduced humification and thus a wetter mire surface.

Results The results of the analyses are plotted on a diagram produced using the computer programmes TILIA and TILIA*GRAPH (Grimm 1987). The dates on the diagram are provided by radiocarbon determinations, linear interpolation between dated levels for some zone boundaries, whilst additional dating control was provided by dendrochronological dates (see Caseldine et al. 2005). Figure 14.3 shows collated palaeohydrological data including humification, plant macrofossil and reconstructed water table as derived from transfer functions for testate amoebae (Woodland et al. 1998). The transfer function for mean annual depth to water table was applied using weighted averaging calibration (see Woodland et al. 1998; Charman et al. 2000 for detailed discussion). The macrofossil content for each sample was assessed on two scales–the relative percentage of the different groups of macrofossils and the percentage of leaves of different Sphagnum species (if present) making up the Sphagna fraction of the sample. The estimates are converted to percentages for data presentation. Selected taxa from the palynological analyses are also presented, with percentages calculated as % TLP (Total Land

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Pollen) and % TLP + spores for Sphagnum. Calluna vulgaris, Cyperaceae and Sphagnum may be regarded as deriving from local peat-forming vegetation components and these records thus provide additional information on palaeohydrological changes on the mire surface. Poaceae is also included, as although the fluctuation of this curve is largely related to changes in the area of woodland cover on the dry land around the bog (Caseldine et al. 2005), some of this family may also derive from wetland grasses such as Phragmites. This diagram has been divided into zones for discussion and interpretation primarily on the basis of changes in the water table and humification curves. Interpretation of the macrofossil record is approached in a qualitative manner with no attempt made to convert these data into Dupont indices (cf. Charman et al. 1999). Tables 14.1 and 14.2 summarise the major characteristics of the testate amoebae, macrofossil and humification analyses. Depth/ zo n e

D escrip tion of major z one ch aracteristics

T18.6 0-0.11m

Marked reduction in A.flavum and increase in H.subflava and D.pulex-type. A.muscorum and A.discoides also decline.

T18.5 0.11-0.32m

Reduction in H.subflava and concomitant increases in A.flavum and A.wrightianum, although the latter species disappears from record before close of zone. A.discoides also well represented.

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T18.4 0.32-0.63m

H.subflava, A.muscorum and D.pulex-type increase with A.flavum and A.wrightianum declining.

T18.3 0.6-0.70m

Marked peaks in Amphitrema flavum, Amphitrema wrightianum and Arcella discoides. A.muscorum, D.pulex-type and H.subflava demonstrate marked reductions. T.arcula and C.arcelloides disappear from record.

T18.2 0.70-0.90m

Trignopyxis arcula and Cyclopyxis arcelloides demonstrate low peaks at base of zone. Hyalosphenia subflava, Difflugia pulex-type and Assulina muscorum form major components of species assemblage.

T18.1

Testates absent aside from single sample at 1.15 m. 0.90-1.50m

Table 14.1: Major characteristics of testate amoebae assemblages from Killoran 18.

Discussion Comparability of Proxy Records Testates are absent from the basal zone of DER18, with the exception of a single sample. This is not surprising, as the basal c. 0.9 m section–dating to 2270 cal. BC to shortly

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before 1310 cal. BC–consists of reed fen peat in which testates tend to be absent or present in very low concentrations (Gearey, unpublished data). The macrofossil record reflects this situation with monocotyledons dominating the record aside from a few wood fragments and rare ericaceous rootlets. Generally, treeless reed fen peat such as this might be expected to have a water content of c. 90% (Casparie 2005) and as such very wet conditions are evidenced. The solitary sample at 1.15 m that contained countable numbers of testates may represent incipient raised bog growth (W. Casparie, pers. comm.) and it is perhaps significant that Sphagnum spores begin to form a consistent curve after this point, possibly reflecting this process as pockets of bog-moss began to develop amongst the reed fen. This may also be apparent in the humification record, which shows a certain amount of fluctuation in the lower half of the zone, but shows a general upwards trend rising to a peak around 110 cm. Humification measures are usually only considered for truly ombrotrophic peat as fen peat wetness is controlled both by groundwater movement and precipitation. Depth/ zo n e

D escrip tion of maj or z one ch aracter ist ic s

600

T18.6 0-0.11m

T18.5 0.11-0.32m

T18.4 0.32-0.63m

Transition to monocotyledon dominance marked by peak in Eriophorum. Sphagnum reduced to minor proportion of record although top sample sees recovery. Humification: Values fluctuate at opening of zone, but fall to less than 15% by close of diagram. Sphagnum imbricatum dominant, although small increase in Section Acutifolia in middle of zone. Humification: Marked increase to c. 40% in lower half of zone followed by drastic reduction to below 10%. Lower half of zone dominated by monocotyledons with low but consistent ericaceous remains. Sphagnum increasing after 0.50 m, but with fluctuating proportions and monocts dominating towards close of zone. Sphagnum imbricatum appearing as dominant Sphagna. Humification: Sudden fall to below 10% in lower half of zone with steady increase to c. 30% by top of zone.

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T18.3 0.6-0.70m

Increase in Sphagnum Section Acutifolia to form c. 50% sample, with Section Cuspidata and S.cuspidatum peak at top of zone. Humification: Increase to 30%.

T18.2 0.70-0.90m

Monocotyledons with rare Sphagnum towards top of zone. Leaves too poorly preserved to determine sphagna group/ species. Humification: Fluctuating between 10-25%.

T18.1 0.90-1.50m increasing

Moncotyledons with rare wood and ericaceous fragments. Pocket of Eriophorum observed at base of zone. Humification: Values oscillating between less than 10% to 20% in lower half of zone, to between 25-30% in upper half of zone.

Table 14.2: Summary of macrofossil assemblages and humification data for the Killoran 18 sequence.

According to Casparie (2005), the construction of Killoran 18 caused a major shift in the local mire hydrology. The compression of the reed fen peat by the weight of the stones used to pave the causeway facilitated the flooding of the surface with acidic waters within a short space of time

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(perhaps as little as 40 years) leading to the growth of ombrotrophic peat over the line of Killoran 18. The changes in the mire microenvironment are reflected in the palaeohydrological data with testates present in countable concentrations from the opening of T18.2. The fauna in the basal samples in this zone are distinguished by Cyclopyxis arcelloides-type and Trignopyxis arcula, species that are common in drier, mesotrophic mires (Tolonen et al. 1994; Hendon et al. 2001) rather than full ombrotrophic conditions. A peak in Calluna vulgaris and reduction in Sphagnum spores at the opening of T18.2 would also seem to support the idea of a relatively dry microenvironment at this time. This indicates that between approximately 1640 cal. BC (the abandonment of the causeway) and shortly before 1310 cal. BC a transitional phase of mire development occurred prior to fully ombrotrophic conditions. Such a phase has been identified at the base of ombrotrophic mires in England (Hughes et al. 2000b). Whilst the humification curve does show a progressive shift to wetter conditions after 1640 cal. BC, neither it nor the macrofossil record, which is dominated by monocotyledons, reflects the subtle changes indicated by the testates. Local Sphagnum growth is not reflected in the macrofossil record until the upper part of T18.2, with only rare Sphagnum leaves present. This may be the result of differential decay of Sphagnum during early stages of raised bog growth and the comparatively dry conditions referred to above, but low percentages of Sphagnum spores support the contention that bog-moss was not a major constituent of the local vegetation at this time. The reconstructed water table suggests fairly deep, stable water tables between 1310 cal. BC and 1000 cal.

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BC, whilst the humification record shows a certain amount of fluctuation and is difficult to interpret. All the proxies attest a major increase in surface wetness after 1000 cal. BC although the wettest periods, as reflected by the reconstructed water table and humification record in T18.3, are slightly out of phase. The reconstructed water table reaches a highpoint at 68 cm, largely as a result of an increase in Anphitrema flavum and marked decrease in Hyalosphenia subflava. A. flavum is very typical of wet, acidic conditions, indicating that the transition to raised bog was complete by this zone. Indeed, the macrofossil record shows that Sphagnum became a significant part of the peat-forming vegetation at this point, consisting of Sphagnum Section Acutifolia. Reconstructed water tables had begun to fall by the point at which the humification curve reaches a peak at 65 cm, with the pool species S. cuspidatum recorded, although monocotyledons are recorded as the major component of the macrofossil record. Peaks in Poaceae and Cyperaceae are evident in the pollen record, suggesting that the monocotyledons represented by the macrofossil record consisted of grasses as well as sedges. Falls in reconstructed water table and humification values at the opening of T18.4, estimated to date to approximately 800 cal. BC indicate a shift to drier conditions although, as observed above, the water table data suggest this shift begins in T18.3, around 65 cm, whilst the humification curve falls slightly later at 62 cm. The driest period as reflected by humification values occurs just before 600 cal. BC at 55 cm, after which a steady increase in values across the zone suggests a progressive trend towards wetter conditions. The water table data, on the other hand, show a shift to deeper

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water tables followed by a similar but less pronounced trend to a wetter surface after 40 cm. The testate record is dominated by H. subflava, an indicator of dry conditions often found in modern assemblages in drained peatlands (Tolonen 1986). Difflugia pulex is also associated with H. subflava–this is a rare taxon in modern testate assemblages, but at Derryville it appears to correspond to relatively dry conditions (cf. Hendon 1998). The macrofossil record supports the generally drier conditions indicated at the beginning of T18.4, with monocotyledons dominating and Sphagnum disappearing from the record between c. 60–65 cm. The re-appearance of Sphagnum in the macrofossils around 600 cal. BC coincides with the wet shift as interpreted from the humification data, but the relative proportions of macrofossils and Sphagnum show a degree of oscillation with a consistent trend to monocotyledons evident towards the top of the zone. Sphagnum imbricatum appears as the main Sphagna species represented above 50 cm. The pollen and spore records show marked falls in Sphagnum, Poaceae and Cyperaceae whilst an increase in Calluna vulgaris at the opening of the zone supports the suggestion of a locally drier peat surface. The Sphagnum curve shows erratic increases approximately in line with the appearance of S. imbricatum as a peat forming species. All the proxies indicate hydrological changes in T18.5 although, as previously, there is some discrepancy regarding their timing and extent. The water table data shows consistently high water tables across the zone from 200 cal. BC, with little fluctuation. The humification record indicates a significant wet phase towards the middle of the zone, before displaying a drastic fall in the upper half. The macrofossil

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record seems to generally parallel the water table, but also displays possibly more subtle changes that seem to only be reflected in the pollen data. Sphagnum imbricatum dominates the Sphagna although a peak in Section Acutifolia suggests some form of shift possibly towards drier conditions in the middle of the zone. A fall in the representation of Sphagnum and increase in Cyperaceae across the same levels would appear to support this contention. The water table data indicate that any such fluctuation was of low amplitude, with only a slight decrease in the water table observed. The marked dry shift in humification is difficult to account for since all the other proxies indicate wet conditions towards the close of the zone. Although both water table and humification records demonstrate some fluctuation in mire surface wetness in T18.5, the general trend to the close of the diagram is towards drier conditions. However, there is again a discrepancy between the two records at the opening of T18.6, with falling water tables after cal. AD 80 closely corresponding to the replacement of Sphagnum with Eriophorum and then monocotyledons in the macrofossil record. Eriophorum is adapted to deep water tables and is often abundant on mires with high water tables in the spring, followed by drier peat surfaces in the late summer (Gimmingham 1964). Hughes et al. (2000b) point out that increased levels of phosphorous, which may be produced as a result of increased humification of raised bog peat, favour the growth of this species. The pollen record also supports generally drier conditions with falls in Sphagnum and Cyperaceae coincident with slight increases in Calluna vulgaris. The humification record, on the other hand, increases sharply at the opening of the zone, indicating a wetter mire surface.

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Conclusions: Observations Regarding the Proxy Records at Derryville 1. The general pattern of wet-dry shifts in the humification and water table records tends to be very similar. Hence, dry episodes can be identified between the following periods: just before 1310 cal. BC–1000 cal. BC, 600 cal. BC–200 cal. BC and cal. AD 80–c. cal. AD 170. Wet phases are observed between: 1640 cal. BC–1310 cal. BC, 1000 cal. BC–800 cal. BC and 200 cal. BC–cal. AD 80. The macrofossil record also tends to support this pattern, with Sphagnum dominating during periods of increased wetness and monocotyledons/ ericaceous remains during drier periods. 2. The dry shift in T18.4 is a result of a bog burst (i.e. catastrophic failure of the structural and hydrological integrity of the bog), of which there is evidence of at least six between 2200 cal. BC and 200 cal. BC (Casparie 2005; Caseldine and Gearey 2006). As Casparie (2005) observes, water was never the limiting factor to bog development at Derryville. The peat-forming environment was thus extremely dynamic, with sudden transitions to dry conditions as a result of bog bursts, followed by slower shifts to a wetter surface as the bog recovered and ‘recharged’ with water. These results also illustrate the importance of linking ‘micro-stratigraphic’ analyses whenever possible with detailed ‘macro-stratigraphic’ survey. Otherwise, the effects of events such as the bog bursts in the palaeohydrological record might easily be attributed to other factors. The data presented in this paper are from part of the mire, which was in the early stages of the fen-bog transition and had been affected by human activity. However, taken collectively the palaeohydrological data from Derryville (Caseldine et al. 2005; Caseldine and

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Gearey 2006) support the hypothesis that autogenic processes will be the main control on mire development in environments where rainfall is high (Walker and Walker 1961; Tolonen et al. 1985; Foster and Wright 1990). Under such a regime, it is thus likely that any climatic signals in the Derryville palaeohydrological sequences are obscured by the internal dynamics of the system. 3. Discrepancies in each of the proxies between the magnitude and also the exact timing of wet shifts in particular are observed. Some of these are of a minor nature (e.g. T18.3) but others are more marked, such as the divergence between humification data and the water table/macrofossil record in the upper part of T18.5. There is no exact correspondence between any two of the proxies reinforcing the necessity of basing palaeohydrological investigations on such multi-proxy approaches (cf. Chiverrell 2001). The causes of these differences are not entirely clear, but presumably relate to the response of each proxy to changes in different variables within the raised bog system. Humification determinations may rely on differential decay of Sphagnum species (Johnson and Damman 1991) and the humification record shows much greater fluctuation than the water table data (e.g. in T18.2), with the latter tending to show a lower amplitude of change. In some sections slight rises/falls in the water table do correlate with peaks or troughs in the humification curve, perhaps indicating both may be responding to the same factors but to different degrees. Which record represents a more ‘accurate’ picture of the magnitude of palaeohydrological change is unclear. The testates may be less sensitive to minor or brief hydrological shifts; alternatively problems related to incomplete understanding of factors controlling either the processes, or interpretation of, humification data may be at work here (cf. Charman et al. 608

1999; Caseldine et al. 2001). The precision of the macrofossil record may shed more light on this if larger samples and more precise identification of some of the species included in the ‘Monocotyledons category’ (cf. Hughes et al. 2000a; 2000b) were undertaken, but this is unlikely given the changes observed even in the small sample. The dominance of S. imbricatum is problematic as the ecological status of this species remains unclear with respect to the fossil record hindering interpretation (Stoneman et al. 1993). The general behaviour of this species in the macrofossil record at Derryville suggests that it occupied a relatively wide habitat range with respect to water tables, which supports conclusions previously reached by van der Molen and Hoekstra (1988). 4. The fluctuations in the pollen and spore record also tend to correlate closely with wet-dry shifts, with Sphagnum and Cyperaceae increasing during episodes of wetness and Calluna vulgaris responding to drier conditions. The representation of Sphagnum spores is also generally related to the representation of Sphagnum in the macrofossil record although some variation is observed. Differential spore productivity of the various Sphagnum species is probably relevant in these cases (Ivanov 1981; Boatman 1983). Other differences between the macrofossil and pollen records that are observed may be explained by discrepancies between macrofossil sample size and pollen source area. Calluna may be growing close to, but not on, the sampling site and as such may not be well represented in the sediment sample used for macrofossil analysis despite contributing to the palynological content of the sample. The general conclusions thus support hypotheses that Sphagnum percentages are closely related to Sphagnum content of the peat, with spore productivity in turn related to surface wetness (e.g. Conway 1954). However, 609

there is little evidence that fluctuations in Sphagnum spores can be reliably used as indicators of surface wetness (cf. Tipping 1995).

Future Research This paper has presented the results of analyses of one sequence from a complex raised mire system in the Irish midlands. The patterns in the data described above tend to be supported by the results of the other palaeohydrological analyses at the site (Caseldine et al. 2005; Caseldine and Gearey 2006). The purpose of this paper has been to illustrate the fact that palaeohydrological studies thus have great potential to produce detailed records of the development of raised mire systems in Ireland, which in turn may be linked to the distribution and character of archaeological material within such systems. A number of broad issues may therefore be identified for future research: 1. Whilst autogenic factors appear to be the major controlling variable in mire development at Derryville, to what extent is this true of other raised mires? This might be anticipated for large, complex systems in an extremely oceanic climate, but the role of climate in particular remains unclear. Further palaeoenvironmental work with careful site selection is required to investigate this issue, although this is hindered by the damage to many Irish peatlands through peat extraction, which prevents the establishment of the context of the original complete mire system. If raised mires are found to be generally unsuitable for palaeoclimate reconstruction in Ireland, are other peat systems such as blanket mires more sensitive (cf. Blackford and Chambers 1994)? 2. More comparative work is required to examine the relationship between humification, plant macrofossils and 610

water table reconstruction as inferred from testate amoebae. The processes controlling each, as well as the measurement and interpretation of the data in general needs more investigation. 3. Similarly, more work is needed on the contemporary ecology of testate amoebae in Ireland and its relationship to different variables. Although there are marked similarities between the hydrological preference of certain testate species between countries and even continents (Charman et al. 2000), some differences are apparent. The water table reconstructions in this paper are based on transfer functions developed from data from UK mires (Woodland et al. 1998) and it is possible that some of the discrepancies between the water tables as inferred from testates and other proxy records discussed above are a result of this. 4. More and detailed study of palaeohydrological records will allow identification and separation of the role of autogenic and allogenic factors in driving the development of ombrotrophic systems. Allied to this is the necessity of linking such study to archaeological sequences which, as was observed at the beginning of this paper, should help build hypotheses regarding the distribution and nature of cultural remains in raised mires in Ireland. The integrated archaeo-environmental investigations at Derryville demonstrate that the relationship between prehistoric anthropogenic activity in the wetland area and the development of the mire system is complicated, with site construction in response to both wetter and drier conditions (Cross et al. 2001). There is also evidence from Derryville to suggest that human activity can be a controlling variable in the hydrology of the raised mire (Casparie 2005). At present, it is unclear whether the inter-play between wetland development and human response at Derryville is typical or 611

atypical in the Irish context. What is clear is that without a detailed understanding of the palaeohydrological context of archaeological sites, interpretation of the role of these sites and their relationship to the both the local wetland context as well as the wider landscape remains at best speculative.

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Walton Moss, Cumbria, England. Journal of Quaternary Science 13, 15–28. Barber, K. E., Maddy, D., Rose, N., Stevenson, A. C., Stoneman, R. and Thompson, R. 2000. Replicated proxy climate signals over the last 2000 years from two distant UK peat bogs: new evidence for regional palaeoclimate teleconnections. Quaternary Science Reviews 19, 481–7. Blackford, J. J. 1993. Peat bogs as sources of proxy climatic data: past approaches and future research, pp. 225–35 in Chambers, F. (ed.), Climate Change and Human Impact on the Landscape. London: Chapman and Hall. Blackford, J. J. and Chambers, F. M. 1991. Proxy records of climate from blanket mires: evidence for a Dark Age (1400 BP) climatic deterioration in the British Isles. The Holocene 1, 63–7. Blackford, J. J. and Chambers, F. M. 1993. Determining the degree of peat decomposition in peat-based palaeoclimatic studies. International Peat Journal 5, 7–24. Blackford, J. J. and Chambers, F. M. 1995. Proxy climate record for the last 1000 years from Irish blanket peat and a possible link to solar variability. Earth and Planetary Science Letters 133, 145–50. Boatman, D. J. 1983. The Silver Flowe National Nature Reserve, Galloway, Scotland. Journal of Biogeography 10, 163–274. Casparie, W. A. 2005. Peat Morphology and Development of Derryville Bog, Co. Tipperary, pp. 13–55 in Gowen, M., Ó Néill, J. and Philips, M. (eds.), The Lisheen Mine Archaeological Project 1996–1998. Bray: Wordwell. 613

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15 Exploring the Role of Environment in Wetland Archaeological Contexts in Ireland Gill Plunkett and Conor McDermott

Abstract Wetlands have been a prominent feature of the Irish landscape since the early prehistoric period. Systematic archaeological surveys and excavations in recent decades have demonstrated the importance of these environments to past societies throughout the post-glacial era. By its nature, the wetland setting is conducive to the preservation of a wide range of organic materials and also contains an important archive of past environments, a record of both natural conditions and the way in which these were altered by humans. Not surprisingly, therefore, the fields of both wetland and environmental archaeology have been strongly interlinked in Ireland since the early days of palaeoecological research. In wetland contexts, a broad array of palaeoecological approaches can be employed towards the reconstruction of landscape, land-use and management, diet, subsistence and settlement patterns, while the effects of a changing environment on human activity can also be explored.

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In this chapter, examples will be given of the ways in which environmental reconstruction relating to archaeological wetlands can contribute to the greater understanding of past human activity. The first case study looks at the Lower River Bann floodplain where peat and diatomite deposits are associated with recurrent occupation evidence in the Later Mesolithic period. The palaeoenvironmental record reveals a dynamic floodplain system whose wide biodiversity may have had an important influence on the nature of early settlement. Hydrological changes in the floodplain will not only have impacted on the location of former occupation sites, but also on their survival and identification. The second case study draws attention to the accumulating body of archaeological sites, namely trackways, in raised bogs across the country. This impressive archaeological resource provides an ideal medium for integrated palaeoenvironmental reconstructions. In these contexts, focused research agendas can aim to tease out socio-economic, cultural and environmental factors behind the use of wetlands and wider settlement patterns.

Introduction Since the 1980s, the systematic survey and excavation of archaeological sites in Irish bogs have revealed extensive evidence for past human activity. The recognition of the importance of these environments to former cultures has brought the sphere of wetland activity to prominence in Irish archaeology. The suitability of these ecosystems to a wide range of palaeoenvironmental research techniques accentuates the value of the wetland archaeological record, providing excellent opportunities to investigate complex humanenvironment relationships in the past. Environmental studies can not only yield valuable information in terms of diet, subsistence, economy and the effects of human activity 623

on the landscape, but can enable the interplay of environmental change and human activity to be examined.

Figure 15.1: Map of Irish peatlands, showing the extent of archaeological surveys, sites referred to in text and the location of Figure 15.2. Sources: Peatland distribution after

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Aalen et al. 1997, 107; Bord na Móna bogs courtesy of Bord na Móna; Archaeological survey data 2002 from the Irish Archaeological Wetland Unit; Bog areas from Hammond 1979, 24. This chapter provides an overview of the emergence of the field of wetland archaeology in Ireland and the long-established recognition of the value of palaeoecological investigations in these contexts. As an example of the importance of integrating the two disciplines, palaeoenvironmental reconstructions in the Lower Bann floodplain are discussed in terms of their contribution to understanding the nature of the early prehistoric settlement record of the area. The considerable body of evidence for trackway construction in raised bogs is also discussed and the merits, as well as difficulties, of discerning environmental influence on such activity are examined. Figure 15.1 shows the current extent of peatlands, the principle wetland type in Ireland, and indicates the key areas referred to in the text.

History of Research The Development of ‘Wetland Archaeology’ in Ireland The scale of archaeological activity in and around peatlands was recognised at least as early as the eighteenth century when hand-cutting of turf for fuel was a widespread activity throughout the country. Discoveries in bogs were frequent and included not only a wide range of artefact types, but also a variety of sites including trackways, enclosures and habitation sites. A perusal of the Ordnance Survey (OS) Memoirs for the Ulster counties reveals that more than 130 sites and 350 finds were already recognised by the mid-eighteenth century (Plunkett 2003). In recognition of the 625

importance of peatlands with regards to their archaeological heritage, the Board of Works, set up in 1843 by the Commission for Arterial Drainage and Inland Navigation, authorised the recording of sites and collection of finds identified during drainage schemes between 1843–1852 (O’Sullivan 1998, 10). During this period, some 377 artefacts and 25 crannogs were methodically recorded from ten counties (O’Sullivan 1998, 11). Despite this early acknowledgement, wetland studies were slow to develop. Numerous excavations of trackways in raised bogs took place over the following century or so (e.g. FitzGerald 1898; Prendergast 1946–47; Tohall et al. 1955; Rynne 1965). Drainage schemes and periods of lower water-levels in other areas led to the discovery and excavation of a number of important lake settlements (e.g. Hencken 1942; Raftery 1942a). In Britain, significant advances were made in the field of wetland archaeology with the identification of extensive prehistoric activity in the Somerset Levels (Coles and Coles 1986). In Ireland, however, it was not until attention was drawn by a local farmer to a large corduroy road extending across Corlea Bog, Co. Longford, in 1984 (Raftery 1996) that the significance of wetland archaeology was truly realised. The Longford studies highlighted the sheer number and density of archaeological sites in bogs, and prompted action to identify, survey and record the extent of these sites. In 1990, the Irish Archaeological Wetland Unit (IAWU) was established as a joint venture between the then Office of Public Works and University College Dublin with the remit of carrying out a systematic survey of Bord na Móna’s 85,000 ha of bogland under threat from commercial exploitation. In 1998, a further development saw the appointment of Archaeological

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Development Services Ltd. (ADS) as consultants to Bord na Móna with the responsibility of mitigating areas of intense archaeological activity prior to the destruction of countless sites. Wetland archaeological research in Ireland has tended to be biased towards raised bogs and their underlying fen peats. Since the late 1980s, the total number of sites identified in these bogs in the Republic of Ireland amount to over 3,500. Of these, more than 200 have been excavated mainly through the work of Barry Raftery, IAWU, Margaret Gowen and Co. Ltd. and ADS. In Northern Ireland, raised bogs have not received the same attention, although a significant number of sites are known from the OS Memoirs, and a small number of excavations have taken place (e.g. Hurl 1995). A recent assessment of the scale of peatland activity in Northern Ireland indicates that some 1,000 sites and over 700 finds are already recorded from peatlands, although these figures include blanket bogs where archaeological remains frequently pre-date the expansion of peat (Plunkett 2003; Plunkett and Foley 2006). The range of activities represented by these sites is extensive. The majority of structures comprise trackways, which aided movement across the bog, whether to gain access to drier areas or exploit resources available in and around the bog. Less understood are the elusive platform structures, which may have provided a basis for specific activities, such as exploiting the surrounding bog, or leather and wood treatment. Abundant finds of bog butter suggest the use of bogs as a means of cold storage (e.g. Raftery 1942b, 34; Earwood 1997) while certain individual finds and hoards have been linked to ritualistic deposition (e.g. Eogan 1983, 11).

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Enigmatic wooden vessels interpreted by Fry (2000) as miniature boats are known from Drummond Bog, Co. Tyrone, and Drumack and Carney Hill townlands, Co. Antrim, as well as a more recent find from Pallasboy, Co. Westmeath (Murray 2000; 2001), but their exclusive association with bogs may point towards some other function, yet to be determined. Settlements associated with wetlands can be traced from the very earliest occupation known in Ireland. Fenlands and lake sides were important through the Mesolithic. Occupation layers in peat and diatomite deposits along the Lower Bann Valley in north-east Ireland reflect the utilisation of the river floodplain during the same period. Fenlands, lake margins and raised bogs were a focus of settlement in the Late Bronze Age. From the Early Historic period, lake islands–natural or artificial–were widely inhabited, a fashion which was still current into the seventeenth century (O’Sullivan 1998, 168). The choice of these locations for settlement probably stems from a variety of reasons, of which the availability of extensive resources may only be one example. The importance of estuaries has only been recognised in Ireland in the last decade but already, small-scale surveys have revealed a range of site types, including occupation sites, trackways, wooden platforms and Medieval fish traps (O’Sullivan 1995; 1996; O’Sullivan and Daly 1999).

Wetland Archaeology Meets Natural Sciences Towards the end of the nineteenth and during the early twentieth centuries, natural scientists were teaming up with archaeologists in an attempt to understand better the 628

environment in which archaeological sites were found. In Ireland, the Committee for Quaternary Research set up in 1933 marked the consolidation of this collaboration, bringing many aspects of natural sciences to archaeological investigations. Amongst the committee were prominent archaeologists of the day R.A.S. Macalister, Adolf Mahr and C. Blake Whelan, as well as representatives from the fields of botany, geology and natural history (Farrington 1934). For the natural scientists, archaeological finds in bogs were an important means of dating and correlating peat sequences (Jessen 1934). From an archaeological point of view, the scientific techniques also offered a means of establishing chronology (Mahr 1934a, 139), while issues relating to forest development, post-glacial sea-level fluctuations and climate change were of pertinence to understanding the environment in which earlier cultures existed. The ‘intimate correlation of the events of natural and of human history made possible by the peculiar constitution of the fenland’ (Clark 1934, 147) observed in Britain was equally applicable in Irish bogs. Importantly, the value of peat-based studies to archaeology was seen in terms of their contribution to understanding changes in settlement patterns, from which archaeologists could draw inferences relating to cultural changes and adaptations in the past (Mahr 1934a, 140). The wooden cauldron from a bog at Altartate, Co. Monaghan, was to become the subject of the first palynological study by the Committee (Mahr 1934b) and site investigations included archaeological horizons in the peat and diatomite deposits at Toome Bay and Newferry, on the border of Counties Derry and Antrim (Jessen 1936; 1949). Together, a total of 30 archaeological sites were examined. Thereafter, the

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application of pollen, seed, wood and faunal analysis featured frequently in appropriate archaeological contexts. Through the following decades, pollen investigations continued to be applied in wetland archaeological contexts (e.g. Movius 1936; O’Connell 1980; Parkes and Bradshaw 1988) and plant macrofossil studies to a lesser extent (e.g. Mitchell 1972). Faunal studies were commonly undertaken (e.g. Stelfox 1942; Hencken 1950) although the lack of systematic sieving may have contributed to results biased in favour of larger mammals. But despite great advances in the scientific techniques, archaeologists were slow to integrate palaeoenvironmental studies. It was not until the Corlea, Co. Longford, investigations (Raftery 1996) that a multidisciplinary approach, including pollen, peat stratigraphy, wood and insect analyses, was adopted in an attempt to understand the archaeology in the context of its environment (Caseldine et al. 1996; Casparie and Moloney 1996; Reilly 1996, Margaret Gowen and Co. Ltd. 1999). Later investigations at Derryville Bog, Co. Tipperary, between 1996–98 saw the application of environmental techniques to a greater extent still, and included also peat humification, testate amoebae and plant macrofossil studies (see Caseldine and Gearey, this volume; Caseldine et al. 2001). This study marks the acme of combined wetland-environmental studies in Irish archaeology to date.

Environmental Insights into Wetland Environments Modern palaeoecological techniques have improved greatly in quality and range in recent decades. These developments not only enable the immediate environment and specific resources exploited at the site to be examined, but also

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provide a means of placing the site in a much wider environmental context. Advances in dating techniques cannot be underestimated in this respect, as well-defined chronological control is crucial for the establishment of the relationship between sites, and between sites and the environment. Environmental archaeology can be applied within the wetland situation at a number of levels, using a wide range of scientific methods, many of which (pollen, wood, plant macrofossil, faunal, insect and peat studies) are described in this volume. The application of these techniques in the wetland context requires no further explanation above that already presented in other chapters, although it can be noted that the frequent occurrence of sites in a stratified peat matrix makes them particularly suited to environmental investigations. The high level of organic preservation found in wet contexts also ensures a rich and diverse record of both archaeological and ecological information. The potential of integrated environmental programmes when excavating wetland sites is enormous (see ‘Worth a Special Journey’ in Coles and Coles 1996, for an excellent overview of the scope of information to be gained from palaeoenvironmental studies at wetland sites). On a broader level, Fredengren (2002, 59) has questioned the value of using an environmental approach to identify resource exploitation and subsistence, suggesting that more might be gained from posing instead socially-inclined questions of the material. Yet understanding site function, site longevity, subsistence and relationship to the immediate and broader environment are prerequisites to understanding the social implications of any site or area. To dismiss the influence of

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environment or to discount the significance of resource availability is to overlook important factors which would have affected life on a daily basis. This is particularly true of wetland sites, where a delicate balance between environment and the habitability or value (social, economic or symbolic) of an area could easily have been tipped by changes in the former. More ritualistic aspects of wetland use also need to be understood in terms of environment, particularly when dealing with possible animist societies. Potential environmental catastrophes cannot be ignored (floods, droughts, famines, diseases) and may well have altered individual or social behaviour, although the human response need not be as simple as some would suggest (environmental catastrophe does not equal cultural catastrophe, necessarily). It is to be argued, therefore, that environmental information needs to be examined at all levels, from site specific and local information through to regional and temporal patterns. Wetland sites are by their nature highly susceptible to environmental change and are arguably the best means of identifying the impact of changing conditions in the archaeological record. The following section examines some aspects of the human-environment relationship in wetland contexts. In the first example, the importance of reconstructing past environments is considered in relation to Later Mesolithic activity in the Lower Bann Valley. The environmental record highlights the potential of this former wetland for foraging communities, a potential which may have implications for questions of subsistence strategies, settlement patterns and ultimately, social change. The second example considers the ever-increasing bog trackway record. The sensitivity of these ecosystems to environmental change enables the effects of the

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latter on human activity to be explored using a range of palaeoecological techniques. Social, economic and cultural factors will also have determined the nature and frequency of activity on the bogs, however, and the complexity of the interaction between past societies and environment is emphasised.

Floodplain Exploitation and Later Mesolithic Settlement in the Lower Bann Valley Resource availability is perhaps no more crucial to the choice of settlement location at any time than in the Mesolithic period. In terms of biodiversity, wetlands are amongst the most productive ecosystems in the world. Fed by nutrient-rich waters, fenlands and floodplains, in particular, would have been economically important to foragers, offering a wide variety of plant and animal resources, as well as a fresh water supply and building materials. Extensive wetland activity is attested in the Irish Midlands (e.g. Mitchell 1972; Ryan 1980; Stanley 2000; Fredengren 2002), typically concentrated on lake margins. The conventional view of Mesolithic subsistence strategies has tended towards a concept of a mobile society, moving through the landscape in pursuit of seasonally available resources (Woodman 1978, 365). The absence of large mammals in post-glacial Ireland, combined with the tendency for Mesolithic sites to be located close to water resources (coast, lakes, rivers), suggests a fisher-gatherer economy. It has been suggested that the year-round availability of resources in an area could have promoted a more sedentary lifestyle (Cooney and Grogan 1994, 21) despite the lack of settlement evidence known from the period. One possible ‘home’ base has been identified at

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Moynagh Lough, Co. Meath (Bradley 2001), however, but dates to the end of the Later Mesolithic. The Lower Bann Valley and its extensive diatomite deposits are renowned for their association with Later Mesolithic activity (Fig. 15.2). Excavations at Newferry, Co. Antrim, reveal occupational evidence consisting mainly of charcoal spreads and flint scatters, deposited in stratigraphic sequences spanning a period between c. 7500–4000 cal. BC (Smith and Collins 1971; Woodman 1977). A comparable sequence is also recorded on the Derry side of the river at Newferry (Movius 1936), while at Toome Bay, Co. Derry, activity appears to have been focused on a sand ridge which was gradually inundated by rising water-levels (Mitchell 1955). The understanding of Later Mesolithic developments in this area has frequently relied upon assumptions about the environment in which occupation took place. The importance of the Lower Bann during the Mesolithic has long been associated with the salmon and eel populations that abound in the river during the spring and autumn months. Unfortunately, evidence for subsistence is almost entirely lacking from the Later Mesolithic sites in the area, although a limited number of eel and salmonid bones were identified at Newferry Site 3 (Co. Antrim) (Woodman 1977, 193) and raspberry seeds were recorded at Newferry, Co. Derry (Jessen 1936, 33). The occupation levels themselves seem to represent transitory sites, and the lithic assemblages have been interpreted as possible woodworking tools associated with the maintenance of fish-traps and weirs (Woodman 1977, 193). Palaeoecological evidence suggests that Mesolithic activity along the Lower Bann was coincident with an ever changing environment as water-levels fluctuated, river channels

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migrated and boreal forests stabilised (Plunkett et al. 2003). The long-standing interpretation of diatomite deposits as the result of seasonal fluctuations derives from the occurrence of occupation horizons within the sediment (Jessen 1936, 35), and forms the basis of the concept of a floodplain environment exploited seasonally by Mesolithic folk (e.g. Woodman 1977). Indeed, Woodman suggests the use of fish-traps may have been less effective as streams became transformed into marshes and that activity at Newferry dwindled through time as a result (Woodman 1977, 193). Pollen and plant macrofossil studies, however, have failed to support this view of diatomite marshes (e.g. Smith and Collins 1971, 17) but, while this may be due to poor preservation conditions, recent palaeoenvironmental studies in the Toome area suggests that more permanent bodies of open, shallow water should be envisaged (Plunkett et al. 2003, 105). Nevertheless, floodplain peats identified in the Toome area do support the concept of seasonal flooding (Plunkett et al. 2003) although this need not have had a detrimental effect on occupation activity. On the contrary, winter flooding may have promoted a wildfowl population which would have expanded the resources available throughout much of the year. Periods of lower lake-levels, influenced perhaps by short-term climate changes, would have resulted in the occasional exposure of the diatomite flats, enabling opportunistic activity on the surface perhaps for decades at a time. During periods of higher water-levels, the same activity may have been based at the floodplain margins or on drier islands between river channels. Fluctuating water-levels in the area will have contributed significantly to depositional and erosional processes, obscuring or obliterating much evidence for human occupation. This

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considered, the partial nature of the archaeological record is yet further emphasised.

Figure 15.2: Lower Bann Valley, showing location of archaeological sites referred to in the text. 1. Toome Bay (Whelan 1936; Jessen 1949; Mitchell 1955); 2. Newferry, Co. 636

Derry (Jessen 1936; Movius 1936); 3. Newferry, Co. Antrim (Smith and Collins 1971); 4. Newferry Site 3/Newferry II, Co. Antrim (Woodman 1977; Smith 1981); 5. Ballyscullion Bog, Co. Antrim (Smith and Crowder 1966); 6. Toome, Co. Antrim (recent excavation). Diatomite distribution is indicated by grey shading. The environment of the Lower Bann Valley was thus one of a dynamic wetland ecosystem. The river and floodplain resources, coupled with nearby oak-hazel forests on the higher grounds, would have afforded sufficient resources to allow permanent or near-permanent settlements to become established. This does not imply that Mesolithic groups would certainly have opted for a more settled lifestyle. Importantly, however, the pollen record at Newferry suggests some degree of human impact on the nearby woodland during the period of Mesolithic occupation (Smith 1970; 1981), and a clearance phase is similarly seen from a pollen sequence at Ballyscullion Bog, Co. Antrim, dating to the mid-fifth millennium cal. BC (Smith and Crowder 1966). This evidence is consistent with more permanent occupation. The recent identification of extensive Later Mesolithic activity on the slopes of a drumlin at the edge of the floodplain at Toome may prove to be pivotal in this argument. The dates of the settlement are not yet known and post-excavation analysis is on-going (P. McCooey, pers. comm.). Palaeoenvironmental analyses from the site may enable the resource base to be identified and the question of site longevity to be examined. Continuity of activity into the Neolithic period is indicated by a range of artefacts, including pottery, in the upper, albeit disturbed, layers at Newferry Site 3 (Woodman 1977, 185). Pollen records elsewhere at Newferry (Smith and Collins 637

1971, 18) indicate woodland disturbance around the time of the Elm Decline, a pollen event that frequently coincides with the first indisputable evidence for farming activity in Ireland. On the Derry side of the river, the artefact assemblage at this time remains characteristically Mesolithic (Movius 1936), and no typological changes were evident in the sequence recorded by Smith and Collins (1971) east of the river. Arguably less suited to agriculture (although grazing would have been possible), the Lower Bann appears to have retained its former importance to some extent during this transitional period. The archaeological record for floodplain occupation peters out soon thereafter although Neolithic objects are known, without context, from the diatomite deposits (e.g. Smith and Collins 1971) and mid-Neolithic pottery was recovered from the base of the diatomite west of the river (Childe 1936, 37; see Sheridan 1995, table 2.2 for dating of the pottery). The environment of the Lower Bann Valley has undergone immense change since the Later Mesolithic period. Given the modified nature of the area today, it may be difficult to picture the obstacles and resources it afforded to hunter-fisher-gatherers in the past. The archaeological record cannot be reconstructed from environmental analyses alone, but palaeoecological techniques can enable us to understand the potential of an area, as well as to identify how subsequent landscape changes may have altered the surviving record. In the case of the Lower Bann Valley, environmental evidence strongly suggests that the means of supporting year-round settlement did exist during the Later Mesolithic. These resources could well have promoted a sedentary lifestyle which gradually incorporated aspects of a new culture and economy, leading ultimately to a move away from previous

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subsistence strategies. Settlement evidence might therefore be expected along the valley margins. Needless to say, the question of Mesolithic cultural/economic survival into the farming period can only be answered through the archaeological record.

Trackway Activity and the Environment By far the most numerous structures recognised in raised bogs are trackways, of which more than 1,400 examples can be demonstrated to date (IAWU unpublished data). Dating from the Early to Mid-Neolithic period at least, the number of such sites increases rapidly from the Early to Middle Bronze Age and continued to be important throughout the later prehistoric, early historic and Medieval periods. Less sophisticated examples comprise small collections of brushwood, with or without a clearly defined structure, which can be interpreted perhaps as the labour of individuals facilitating their passage through the wetter areas of bog (Fig. 15.3). The majority of such sites at Derryville Bog, Co. Tipperary, appear to have been built to aid the exploitation of marginal woodlands and fen (Cross et al. 2001, 96). More intricate constructions often incorporate large timbers, including planks, and can stretch for over a kilometre through boglands, frequently linking areas of dryland by the shortest route possible. The scale of some sites strongly hints that they are the product of communal labour, and a high level of social organisation must have been required to produce roadways such as Corlea 1, Co. Longford (Fig. 15.4; Raftery 1996, 418). At least one example (Derrynagun Bog, Co. Offaly) appears to have been maintained over several centuries from the Early Medieval period (McDermott 1998, 23).

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The distribution of trackways reveals significant continuity in the use of particular locations through many periods (McDermott 1998; 2001). Dating evidence from Derryville, however, suggests that trackway construction and bog use was often episodic (Cross et al. 2001). Dendrochronological data from numerous sites hints at specific ‘phases’ of activity (Baillie 1993). The tendency for these episodes to follow narrow ring events observed in the Irish dendrochronological master series has led Baillie to speculate a possible environmental link between the two. The use of radiocarbon dating has extended the chronology of trackway construction to include sites of slighter construction. Figure 15.5 shows the distribution of both dendro- and radiocarbon dates for archaeological sites in raised bogs and demonstrates that the radiocarbon dates tend to uphold, if extend, the dendrochronological patterns.

Figure 15.3: Ballynakill 8, Cloncreen Bog, Co. Offaly, a hurdle trackway 3 m in length tied with withies dating to 1409–1054 cal. BC (3019±53 BP; Wl-11727) (courtesy IAWU).

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Multi-proxy studies of bog hydrology such as that outlined by Caseldine and Gearey (this volume; Caseldine et al. 2001) demonstrate the need to understand the bog system as a whole if archaeological sites are to be placed in context. In the Derryville example, autogenic processes are believed to be responsible for changes in the surface wetness of the bog. Here, trackway construction was seen to increase after water-levels were reduced at c. 1250 and 820 cal. BC, although activity during wetter periods was also observed (Cross et al. 2001). The value of the bog and the nature of activity on it changed through time, with a shift from marginal resource exploitation in the Early to Middle Bronze Age through to a more complete integration of the bog into the broader landscape by the early historic period. The Derryville results demonstrate the importance of localised environmental factors in relation to activity at this bog alone. How significant then are the trackway dates from other bogs in the country in terms of environmental indicators?

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Figure 15.4: Corlea 1 Iron Age road, Co. Longford, dated to 148 BC (from Raftery 1996, 34; courtesy B. Raftery).

Figure 15.5: Dating results for anrhaeological sites from Irish raised bogx (sites discovered up to 2002). Only one date per site is shown except where the excavator identified distinct phaser of construction or repair.Fulachta fiadh and

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settlements not included. All radiocarbon dates are calibrated using CALIB rev.4.3 (Stuiver et al.1998). Notes: 1. Where information avaiable; 2. Baillie 1995. Sources: Irish Archaeological Wetland Unit; Irish Radiocarbon Date Database; Breen 1988, 323; Warner et al.1990, 46–50; Raftery 1996, 423; Brindley and Lanting 1998; Margarett Gonven and Co. Ltd. 1999; O Neill 2000)

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Figure 15.6: Dating results for archaeological site from Irish raised bogs by county (sites discovered up to 2002). Archaeological surveys conducted to date have mainly taken place in Counties Tipperary, Offaly and Longford, with a smaller number of investigations in other midland counties (see locations of archaeological surveys in Fig. 15.1). The majority of dating results from Counties Tipperary and Longford derive from excavations at Derryville Bog, and Derryoghil and Corlea Bogs respectively. Most of the dates from Co. Offaly are from sites identified during archaeological surveys as part of a systematic dating strategy (McDermott 2001). An examination of the dates of sites in terms of county distribution (Fig. 15.6) reveals that although some regional differences are apparent, broad trends are also discernible. The main patterns are outlined below. — Middle to Late Bronze Age phases of activity are observed in the three main groups of sites. — A higher number of dendro-dated sites in Offaly in the tenth century BC suggest a local phenomenon, although this area has been subject to a greater level of investigation. — Mid-first millennium BC activity is best seen at Derryville Bog, despite extensive surveys throughout Offaly. — An Early Iron Age phase of construction is most apparent in both the Tipperary and Offaly groups — The ‘gap’ in construction in the first five centuries AD is striking in all areas.

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— An early historic expansion of activity is most notable in Co. Offaly and particularly involves the use of dendro-datable oaks. Patterns such as these can arise from a number of factors, including both social and environmental stimuli. It is important to note that the reasons for wetland use can and will have varied through time, and patterns of activity can only be understood through an examination of all possible scenarios (e.g. Baillie 1993, 11–12). Socio-economic and cultural factors will have entailed resource exploitation, greater activity in an area or movement through the landscape, population expansions and contractions, and changes in settlement patterns. These aspects can only be identified if site function, site distribution and dryland activities are also considered. The large number of trackways of the tenth century BC possibly reflects increased movement through the landscape as new cultural and trade links opened up at the beginning of the Dowris Phase, that final phase of the Irish Late Bronze Age renowned for its prolific metalwork production. The re-emergence of trackway construction from the sixth century AD may relate to the spread of monastic activity and the concomitant social and political changes that ensued, although it is not yet clear to what extent suitable environmental conditions may have facilitated the use of bogs. Bog hydrology is arguably the single most important environmental factor likely to influence potential trackway distribution patterns. At Derryville Bog, this appears to have been controlled by local hydrological dynamics, the recognition of which was facilitated by peat stratigraphic, testate amoebae, humification and plant macrofossil data

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(Caseldine et al. 2001). Such local effects can be caused by bog bursts (as at Derryville) or changes in internal drainage patterns but would not be expected to occur contemporaneously at other sites, unless resulting from a wider environmental stimulus. The possible impact of human activity (forest clearance in the region, grazing or burning on the bog) on the hydrology of the bog should not be overlooked, and can be detected through the pollen and charcoal records (e.g. Chambers 1991). The identification of extensive and broadly contemporary changes in hydrology in multiple bog systems, however, points towards a climate-driven change. A number of studies have been undertaken in Ireland to determine changes in bog surface wetness over time (Holmes 1998; van Geel et al. 1998; Plunkett 1999) and suggest that short-term environmental events did influence bog surface hydrology. On the basis of peat humification data from several Irish bogs, Plunkett (1999, 229) suggests that during the Middle to Late Bronze Age, expansions of trackway construction took place during periods of drier/warmer conditions but the effects of increased surface wetness on bog use were more limited. The recognition of the impact of these events on the wetland archaeological record requires extensive and dedicated research, involving multiple bog studies where extensive wetland use is attested. Such an undertaking has yet to be initiated in Ireland, although the Derryville Project provides a good model for a starting point. From an archaeological point of view, the evidence available to date already provides a basis for the examination of numerous hypotheses regarding the socio-economic and perhaps political significance of bog activity and its relationship to wider cultural developments in the past. Continuing surveys are likely to extend this body of

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evidence not only geographically but also further back in time as earlier horizons of peat become exposed through commercial peat cutting (cf. Murray et al. 2002). It is argued, however, that the role of environment must be given due consideration before human factors can be understood fully in context. The accumulation of evidence for environmental change in bog ecosystems is transferable to many aspects of the archaeological record. An improved understanding of the nature and effect of environmental change in the past will facilitate a more impartial assessment of its impact in other areas of that record. Later Bronze Age hoard deposition in wet contexts, for example, has been linked (though not demonstrated) to a deteriorating climate in the mid-first millennium BC (e.g. Coles and Harding 1979, 484). Such a relationship is impossible to identify through the material record alone, but the effects of any such change on other aspects of activity (e.g. agriculture, settlement patterns) can be examined for indications of social stress brought on by the proposed deterioration. Only when such issues are examined in full will the significance of the archaeological record be realised from a more objective standpoint.

Concluding Remarks Wetlands have been a significant feature of the Irish landscape for millennia. Containing both an archive of past human activity and environmental evolution, their importance as a key to understanding the past is perhaps unparalleled in any other archaeological context. Ideal for many palaeoecological research techniques, they provide a rare opportunity to understand the relationship between society and the environment in the past. This relationship must be

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acknowledged even by the strongest opponents of environmental determinism, because whether governed by ecological changes or master of their surroundings, past societies interacted with that environment, and the nature of this interaction can tell us much about life in the past. Environmental research in Irish wetlands today is largely being conducted in the realms of palaeoecology. In terms of landscape studies, this research contributes significantly to environmental reconstructions and can throw light on resource availability, levels of human impact in the surroundings and changing ecological and climatic conditions. While these investigations can provide important information of value also to archaeologists, specific archaeological questions are not being tackled. A small degree of environmental research has been undertaken in relation to wetland surveys and excavations through the work of the IAWU and ADS, but the lack of funding almost ensures that these results remain relevant to site specific investigations only. The Derryville Project is a rare example of a more thorough and integrated undertaking, combining wetland, dryland and environmental evidence in an effort to understand both the archaeology and the archaeological record in context. Comparative studies in other areas of the country would undoubtedly expand our understanding of the motives and drives behind many aspects of past human activities. The question is remains, is the onus on the governments, the developers or the universities to ensure that this work is undertaken? In reality, the full potential for such studies cannot be realised without all three strands of involvement. The greater part of the financial responsibility must surely rest with those who cause the excavations to be undertaken which is, in most cases, the developer. The

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principal obligation to ensure that appropriate research is conducted to the highest standards possible, however, lies with the governments who permit the development to take place and the universities in which specific research agendas should be formulated, implemented and brought to fruition.

References Aalen, F. H. A., Whelan, K. and Stout, M. (eds.) Atlas of the Irish Rural Landscape. Cork: Cork University Press. Baillie, M. G. L. 1993. Dark Ages and dendrochronology. Emania 11, 3–12. Baillie, M. G. L. 1995. A Slice through Time: Dendrochronology and Precision Dating. London: B. T. Batsford Ltd. Bradley, J. 2001. A Late Mesolithic settlement site in eastern Ireland, pp. 299–306 in Raftery, B. and Hickey, J. (eds.), Recent Developments in Wetland Research (Seandálíocht Monograph 3 and WARP Occasional Paper 14). Dublin: University College Dublin. Breen, T. C. 1988. Excavation of a roadway at Bloomhill Bog, Co. Offaly. Proceedings of the Royal Irish Academy 88C, 321–39. Brindley, A. L. and Lanting, J. N. 1998. Radiocarbon dates for Irish trackways. Journal of Irish Archaeology 9, 45–68. Caseldine, C., Hatton, J., Huber, U., Chiverrell, R. and Woolley, N. 1996. Palaeoecological work at Corlea (1992–1995), pp. 393–4 in Raftery, B., Trackway Excavations in the Mountdillon Bogs, Co. Longford, 1985–1991 (Irish Archaeological Wetland Unit Transactions 3). Dublin: Crannóg Publications. 649

Caseldine, C., Gearey, B., Hatton, J., Reilly, E., Stuijts, I. and Casparie, W. 2001. From the wet to the dry: palaeoecological studies at Derryville, Co. Tipperary, Ireland (Lisheen Archaeological Project), pp. 99–113 in Raftery, B. and Hickey, J. (eds.), Recent Developments in Wetland Research (Seandálíocht Monograph 3 and WARP Occasional Paper 14). Dublin: University College Dublin. Casparie, W. A. and Moloney, A. 1996. Corlea 1: palaeo-environmental aspects of the trackway, pp. 367–77 in Raftery, B. and Hickey, J. (eds.), Recent Developments in Wetland Research (Seandálíocht Monograph 3 and Wetland Archaeology Research Project Occasional Paper 14). Dublin: University College Dublin. Chambers, F. M. 1991. Peat humification: proxy climatic record or indicator of land-use history? pp. 27–43 in Limbrey, S. (ed.), Soils and Human Settlement (Welsh Soils Discussion Group Report No. 26). Bangor: Welsh Soils Discussion Group. Childe, V. G. 1936. Report on Neolithic pottery from Newferry, County Londonderry, pp. 37–9 in Movius, H. L., A Neolithic site on the River Bann. Proceedings of the Royal Irish Academy 43C, 17–40. Clark, J. G. D. 1934. Recent research on the post-glacial deposits of the English fenland. Irish Naturalists’ Journal 5, 144–52. Coles, B. and Coles, J. 1986. Sweet Track to Glastonbury; the Somerset Levels in Prehistory. London: Thames and Hudson. Coles, J. and Coles, B. 1996. Enlarging the Past (Society of Antiquaries of Scotland Monograph Series 11 and Wetland

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Coles, J. M. and Harding, A. F. 1979. The Bronze Age in Europe. London: Methuen and Co. Cooney, G. and Grogan, E. 1994. Irish Prehistory: A Social Perspective. Bray: Wordwell. Cross, S., Murray, C., Ó Néill, J. and Stevens, P. 2001. Derryville Bog: a vernacular landscape in the Irish Midlands, pp. 87–97 in Raftery, B. and Hickey, J. (eds.), Recent Developments in Wetland Research (Seandálíocht Monograph 3 and Wetland Archaeology Research Project Occasional Paper 14). Dublin: University College Dublin. Earwood, C. 1997. Bog-butter: a two thousand year history. Journal of Irish Archaeology 8, 25–42. Eogan, G. 1983. Hoards of the Irish Later Bronze Age. Dublin: University College Dublin. Farrington, A. 1934. The organisation of the Committee for Quaternary Research in Ireland. Irish Naturalists’ Journal 5, 128–30. FitzGerald, W. 1898. An ancient footway of wooden planks across the Monavullagh Bog. Journal of the Royal Society of Antiquaries of Ireland 28, 417–8. Fredengren, C. 2002. Crannogs. Bray: Wordwell. Fry, M. 2000. Coití: Logboats from Northern Ireland. Antrim: Greystone Press. Hammond, R. F. 1979. The Peatlands of Ireland (Soil Survey Bulletin 35). Dublin: An Foras Talúntais.

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Hencken, H. O’N. 1942. Ballinderry Crannog No. 2. Proceedings of the Royal Irish Academy 47C, 1–76. Hencken, H. O’N. 1950. Lagore Crannog: an Irish Royal residence of the 7th to 10th centuries A.D. Proceedings of the Royal Irish Academy 53C, 1–247. Holmes, J. E. 1998. A Tephra-Dated Study of Vegetation and Climate in the Mid-Holocene of North-West Europe. Unpublished Ph.D. thesis, Queen’s University Belfast. Hurl, D. 1995. Killymoon–new light on the Late Bronze Age. Archaeology Ireland 9 (4), 24–7. Irish Radiocarbon Database. http://www.ucc.ie/archaeology/ radiocarbon/ (17 February 2003). Jessen, K. 1934. Preliminary report on bog investigations in Ireland, 1934. Irish Naturalists’ Journal 5, 130–4. Jessen, K. 1936. Palaeobotanical report on the Stone Age site at Newferry, County Londonderry, pp. 31–7 in Movius, H. L, A Neolithic site on the River Bann, Proceedings of the Royal Irish Academy 43C, 17–40. Jessen, K. 1949. Studies in Late Quaternary deposits and flora-history of Ireland. Proceedings of the Royal Irish Academy 52B, 85–290. Mahr, A. 1934a. Quaternary research in Ireland, 1934, from the archaeological viewpoint. Irish Naturalists’ Journal 5, 137–44. Mahr, A. 1934b. A wooden cauldron from Altartate, Co. Monaghan. Proceedings of the Royal Irish Academy 42C, 11–29.

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Margaret Gowen and Co. Ltd. 1999. Lisheen Archaeological Report, Lisheen Mine, Co. Tipperary. Limited circulation unpublished report commissioned by Minorco Lisheen Ltd. McDermott, C. 1998. The prehistory of the Offaly peatlands, pp. 1–28 in Nolan, W. and O’Neill, T. P. (eds.), Offaly: History and Society. Dublin: Geography Publications. McDermott, C. 2001. Trekkers through time: recent archaeological survey results from Co. Offaly, Ireland, pp. 13–25 in Raftery, B. and Hickey, J. (eds.), Recent Developments in Wetland Research (Seandálíocht Monograph 3 and Wetland Archaeology Research Project Occasional Paper 14). Dublin: University College Dublin. Mitchell, G. F. 1955. The Mesolithic site at Toome Bay, Co. Londonderry. Ulster Journal of Archaeology 18, 1–16. Mitchell, G. F. 1972. Some Ultimate Larnian sites at Lake Derravaragh, Co. Westmeath. Journal of the Royal Society of Antiquaries of Ireland 102, 160–72. Movius, H. L. 1936. A Neolithic site on the River Bann. Proceedings of the Royal Irish Academy 43C, 17–40. Murray, C. 2000. A wooden vessel from Co. Westmeath, Ireland. News WARP 28, 7–8. Murray, C. 2001. Archaeological discoveries in Toar Bog, Co. Westmeath. Peatland News 31, 54–5. Murray, C., Stanley, M., McDermott, C. and Moore, C. 2002. Sticks and stones: Irish Archaeological Wetland Unit survey 2002. Archaeology Ireland 16 (4), 16–19.

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O’Connell, M. 1980. Pollen analysis of fen peat from a Mesolithic site at Lough Boora, County Offaly, Ireland. Journal of Life Sciences of the Royal Dublin Society 2, 45–9. Ó Néill, J. 2000. A summary of investigations by the Lisheen Archaeological Project. Tipperary Historical Journal 2000, 173–90. O’Sullivan, A. 1995. Marshlanders. Archaeology Ireland 9 (1), 8–11. O’Sullivan, A. 1996. Later Bronze Age intertidal discoveries on north Munster estuaries. Discovery Programme Reports 4, 63–72. O’Sullivan, A. 1998. The Archaeology of Lake Settlements in Ireland (Discovery Programme Monographs 4). Dublin: Royal Irish Academy. O’Sullivan, A. and Daly, A. 1999. Prehistoric and Medieval coastal settlement and wetland exploitation in the Shannon estuary, Ireland, pp. 177–84 in Coles, B., Coles, J. and Jørgensen, M. S. (eds.), Bog Bodies, Sacred Sites and Wetland Archaeology (Proceedings of a conference held by WARP and the National Museum of Denmark, in conjunction with Silkeborg Museum, Jutland, September 1996, Wetland Archaeology Research Project Occasional Paper 12). Exeter: Wetland Archaeology Research Project. Parkes, H. and Bradshaw, R. 1988. Bloomhill pollen analysis, pp. 335–9 in Breen, T. C., Excavation of a roadway at Bloomhill Bog, County Offaly. Proceedings of the Royal Irish Academy 88C, 321–39.

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Plunkett, G. M. 1999: Environmental Change in the Late Bronze Age in Ireland (1200–600 cal BC). Unpublished Ph.D. thesis, Queen’s University Belfast. Plunkett, G. 2003. Final Report on the Assessment of Peatland Archaeology in Northern Ireland. Unpublished report to the Environment and Heritage Service: Built Heritage. Plunkett, G. and Foley, C. 2006. Peatland archaeology in Northern Ireland: an evaluation. Journal of Wetland Archaeology 6, 83–97. Plunkett, G. M., Hall, V. A. and Whitehouse, N. J. 2003. Environmental Investigations along the Toome By-Pass: Final Report. Unpublished report to the Environment and Heritage Service: Natural Heritage. Prendergast, E. 1946–1947. Togher at Kellysgrove, Co. Galway. Journal of the Galway Archaeological and History Society 22, 15–18. Raftery, J. 1942a. Knocknalappa crannóg, Co. Clare. North Munster Antiquarian Journal 3, 53–72. Raftery, J. 1942b. A bog-butter vessel from near Tuam, Co. Galway. Journal of the Galway Archaeological and History Society 20, 31–8. Raftery, B. 1996. Trackway Excavations in the Mountdillon Bogs, Co. Longford, 1985–1991 (Irish Archaeological Wetland Unit Transactions 3). Dublin: Crannóg Publications. Reilly, E. 1996. The insect fauna (Coleoptera) from the Neolithic trackways Corlea 9 and 10: the environmental implications, pp. 403–9 in Raftery, B., Trackway Excavations

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in the Mountdillon Bogs, Co. Longford, 1985–1991 (Irish Archaeological Wetland Unit Transactions 3). Dublin: Crannóg Publications. Ryan, M. 1980. An early Irish Mesolithic site in the Irish midlands. Antiquity 54, 46–7. Rynne, E. 1965. Toghers in Littleton Bog, Co. Tipperary. North Munster Antiquarian Journal 9, 138–44. Sheridan, A. 1995. Irish Neolithic pottery: the story in 1995, pp. 3–21 in Kinnes, I. and Varndell, G. (eds.), Unbaked Urns of Rudely Shape, Essays on British and Irish Pottery for Ian Longworth (Oxbow Monograph 55). Oxford: Oxbow. Smith, A. G. 1970. The influence of Mesolithic and Neolithic man on British vegetation: a discussion, pp. 81–96 in Walker, D. and West, R. G. (eds.), Studies in the Vegetation History of the British Isles. Cambridge: Cambridge University Press. Smith, A. G. 1981. Palynology of a Mesolithic-Neolithic site in County Antrim, N. Ireland. Proceedings of the IVth International Palynology Conference (1976–1977), Lucknow, 248–57. Smith, A. G. and Collins, A. E. P. 1971. The stratigraphy, palynology and archaeology of diatomite deposits at Newferry, Co. Antrim, Northern Ireland. Ulster Journal of Archaeology 34, 3–25. Smith, A. G. and Crowder, A. 1966. Final Report to the Wenner-Gren Foundation on Grant no. 1446–to aid archaeological research on early agricultural systems. Unpublished report.

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Stanley, M. 2000. An Irish Star Carr. Archaeology Ireland 14 (4), 30–2. Stelfox, A. W. 1942. Report on bones from Knocknalappa crannóg, pp. 67–9 in Raftery, J., Knocknalappa crannóg, Co Clare. North Munster Antiquarian Journal 3, 53–72. Stuiver, M., Reimer, P. J., Bard, E., Beck, J. W., Burr, G. S., Hughen, K. A., Kromer, B., McCormac, F. G., van der Plicht, J. and Spurk, M. 1998. INTCAL98 radiocarbon age calibration, 24,000–0 cal BP. Radiocarbon 40, 1041–83. Tohall, P, de Vries, H. L. and van Zeist, W. 1955. A trackway in Corlona Bog, Co. Leitrim. Journal of the Royal Society of Antiquaries of Ireland 85, 77–83. van Geel, B., van der Plicht, J., Kilian, M. R., Klaver, E. R., Kouwenberg, J. H. M., Renssen, H., Reynaud-Farrera, I. and Waterbolk, H. T. 1998. The sharp rise of δ14C c. 800 cal BC: possible causes, related climatic teleconnections and the impact on human environments. Radiocarbon 40, 535–50. Warner, R. B., Mallory, J. P. and Baillie, M. G. L. 1990. Irish Early Iron Age sites: a provisional map of absolute dated sites. Emania 7, 46–50. Whelan, C. B. 1936. Report on Neolithic pottery from Newferry, County Londonderry, pp. 39–40 in Movius, H. L., A Neolithic site on the River Bann. Proceedings of the Royal Irish Academy 43C, 17–40. Woodman, P. C. 1977. Recent excavations at Newferry, Co. Antrim. Proceedings of the Prehistoric Society 43, 155–200. Woodman, P. C. 1978. The chronology and economy of the Irish Mesolithic: some working hypotheses, pp. 333–70 in

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Mellars, P. (ed.), The Early Postglacial Settlement of Northern Europe, An Ecological Perspective. London: Duckworth.

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16 Heritage Legislation and Environmental Archaeology in Ireland John Ó Néill

Abstract Following the partition of Ireland into Northern Ireland and Saorstát Eireann in 1921, the two separate legislative jurisdictions replaced the existing Ancient Monuments Protection (Ireland) Act of 1882 with the Ancient Monuments Act (Northern Ireland) 1926 and the National Monuments Act 1930, respectively. The following paper outlines the development of heritage legislation on both sides of the border, dealing first with Northern Ireland, then with the Republic of Ireland. In this context, the existing legislation and environmental archaeology are discussed.

Introduction The following paper details the development of the legislative instruments relevant to archaeology in both Northern Ireland and the Republic of Ireland. The background to the legislation has been outlined elsewhere (e.g. An Roinn Ealaíon, Oidhreacta, Gaeltachta agus Oileán 1999, 15–21; Brannon 2002), and is reproduced here for ease of reference. The impact of such legislation on environmental archaeology is

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examined, both in the context of its protection and policy against the reality of its practice, particularly with regard to excavation. The evolution of the legislation and its current status is central to understanding its influence on the practice of environmental archaeology in Ireland.

Heritage Legislation in Northern Ireland In Northern Ireland the 1882 Act was replaced in 1926 by the Ancient Monuments Act (Northern Ireland) 1926. This included definitions of ‘monument’ and ‘ancient monument’, provision for the guardianship of monuments, an Ancient Monuments Advisory Committee, penalties for damage to monuments, preservation orders for threatened monuments and provision to acquire monuments by gift or deed. Under the law, the discovery of an ‘archaeological object’ was to be reported to the Ancient Monuments Advisory Committee within 14 days. An ‘archaeological object’ was defined as having an archaeological value greater than its intrinsic value. The Act had no effect on ‘treasure trove’. The Belfast Natural History and Philosophical Society, Belfast Naturalists Field Club, Deputy Keeper of the Records of Northern Ireland, Ministry of Education, Queen’s University Belfast, the Royal Institute of British Architects, the Royal Irish Academy and the Royal Society of Antiquaries of Ireland all supplied representatives for the Ancient Monuments Advisory Committee. In 1937, the Ancient Monuments Act (Northern Ireland) 1926 was amended. The new Ancient Monuments Act (Northern Ireland) 1937 provided for powers of entry to lands and re-named the Ancient Monuments Advisory Committee as the Ancient Monuments Advisory Council and made provision for extending membership to include museum curators. Under 660

the amendment, a provision was introduced that made excavation for archaeological purposes subject to the issuing of a licence by the Ministry of Finance. In 1950 the first government archaeological survey was commissioned with the appointment of two professional archaeologists (Hamlin 1992, 41). The results of the survey of County Down saw publication in 1966, although no further county surveys have been published to date. In 1971 the Historic Monuments Act (Northern Ireland) 1971 was passed. This superseded existing legislation with several amendments and additional provisions. It introduced powers for protection orders and the compulsory acquisition of monuments, allowed for the scheduling of historic monuments in private ownership, introduced the requirement to provide notice of works on scheduled monuments and established an advisory Historic Monuments Council. Following the introduction of direct rule from the Westminister Parliament in 1972, the functions of the Historic Monuments Act (Northern Ireland) 1971 passed to the Department of the Environment with the Archaeological Survey evolving into the Historic Monuments and Buildings Branch of the Department. The Protection of Wrecks Act 1973, which affected historic wrecks, was administered through the Department of the Environment. Legislation of great relevance to heritage protection policy was enacted in 1991 as the Planning (Northern Ireland) Order 1991, with the policy outlined in A Planning Strategy for Rural Northern Ireland in 1993. In the same year, all built heritage data was made publicly accessible through the Monuments and Buildings Record under the directive Access to

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Environmental Information Regulations (Northern Ireland) 1993. In 1995 the current legislation, the Historic Monuments and Archaeological Objects (Northern Ireland) Order 1995, came into force. This added a provision of scheduled monument consent, requiring consent for any works that might affect a scheduled monument. Within the Order the term ‘archaeological object’ is defined as:

‘any object, being a chattel (whether in a manufactured or unmanufactured state), which is, or appears to be, of archaeological or historical interest and which has, by reason of such interest, a value substantially greater than its intrinsic value or the value of the materials of which it is composed’. Under the Order, a monument is defined as:

‘(a) any building, structure or works, whether above or below the surface of the land, and any cave or excavation; (b) any site comprising the remains of any such building, structure or works or of any cave or excavation; and (c) any site comprising, or comprising the remains of, any vehicle, vessel, aircraft or other movable structure or part thereof which neither constitutes nor forms part of anything which is a monument within sub-paragraph (a); and any machinery attached to a monument shall be

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regarded as part of the monument if it could not be detached without being dismantled’. The Merchant Shipping Act 1995 allowed the Receiver of Wrecks to administer archaeological materials recovered from a maritime context. In 1996, the Treasure Act 1996 was passed, with a parliamentary code of practice specifically for Northern Ireland. In the same year, the Environment and Heritage Service took over some of the functions of the Department of the Environment (known as the Environment Service from 1990). There are three directorates within the Environment and Heritage Service: Environmental Protection, Natural Heritage, and, Built Heritage. Built Heritage is the current government department with responsibility for the identification, recording and protection of the built, buried and underwater remains of human activity, from prehistoric times to the present. Currently, the most relevant statement of heritage protection policy is Planning Policy Statement No. 6: Planning, Archaeology and the Built Heritage (generally known as PPS6). This document, published in 1999, sets out the criteria for listing and scheduling of buildings and monuments. PPS6 provided for the protection of built heritage within the framework of the development control process. The European Convention on the Protection of Archaeological Heritage (1992) was ratified in 2000 and is generally known as the Valletta Convention. The Countryside Management Scheme was also introduced in 2000 following the enactment of Council Regulation (EC) Number 1257/ 1999 on support for rural development from the European

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Agricultural Guidance and Guarantee Fund and amending and repealing certain legislation. This includes a series of habitats such as wetlands, moorlands, lowland raised bog, land adjacent to lakes as well as archaeological features. The inclusion of many of the former allows for the protection of many sensitive archaeological features and structures by default (Foley 2002, 121). Currently, rescue and mitigation excavations in Northern Ireland are licensed under the Historic Monuments and Archaeological Objects (Northern Ireland) Order 1995 and are, as such, subject to ‘licence to excavate’ conditions (Brannon 2002, 496).

Heritage Legislation in the Republic of Ireland The Oireachtas of Saorstát Eireann replaced the pre-existing Ancient Monuments Protection (Ireland) Act of 1882 with the National Monuments Act 1930 whose functions fell upon the Commissioners of Public Works (now the Office of Public Works). This defined a monument as including:

‘any artificial or partly artificial building, structure, or erection whether above or below the surface of the ground and whether affixed or not affixed to the ground and any cave, stone, or other natural product whether forming part of or attached to or not attached to the ground which has been artificially carved, sculptured or worked upon or which (where it does not form part of the ground) appears to have been purposely put or arranged in position and any prehistoric or ancient tomb, grave or burial deposit, but does not include any building which is for the

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time being habitually used for ecclesiastical purposes’. It also defined the expression archaeological object to mean:

‘any chattel whether in a manufactured or partly manufactured or an unmanufactured state which by reason of the archaeological interest attaching thereto or of its association with any Irish historical event or person has a value substantially greater than its intrinsic (including artistic) value, and the said expression includes ancient human and animal remains and does not include treasure trove in which the rights of the State have not been waived’. The Act allowed for the establishment of a National Monuments Advisory Council and allowed for monuments to be taken into guardianship either by the state or the relevant local authority. This provision included agreements with regard to either inheritance of such monuments or compulsory purchase. Injury to such monuments was prohibited under the Act, and provision was included for preservation orders to be made where necessary, although they required ratification by the Oireachtas within 21 days. The Act also allowed for the creation, by a local authority, of a local advisory committee of the National Monuments Advisory Council. The Act made provision for the maintenance of public access to the monuments in state or local authority guardianship and required the discovery of archaeological objects to be 665

reported to the Gárda Síochána on duty in the district in which an object was found or the Keeper of Irish Antiquities in the National Museum within 14 days. The export or alteration of such archaeological objects was also regulated under the Act, as was excavation for archaeological purposes. With regard to excavation, any alteration of a National Monument was deemed illegal, unless carried out with the written consent of the Commissioners of Public Works. The Act also stated that:

‘… it shall not be lawful for any person, without or otherwise than in accordance with a licence issued by the Commissioners under this section, to dig or excavate in or under any land (whether with or without removing the surface of the land) for the purpose of searching generally for archaeological objects or of searching for, exposing or examining any particular structure or thing of archaeological interest …’. Further provision was included that would allow the Commissioners to add ‘…conditions and restrictions as they shall think proper …’ to such a licence. In a review of legislation, following the establishment of the Republic of Ireland in 1949, several additions and changes were made to the National Monuments Act 1930, known as the National Monuments (Amendment) Act, 1954. This included provisions for temporary preservation orders, unlicensed excavations where there is an imminent threat to a monument or archaeological object and the publication of 666

lists of National Monuments in Iris Oifigiúil. There were also several minor alterations to the 1930 Act, with regard to the composition of the National Monuments Advisory Council and allowing for the removal of a National Monument to another location. While the Ordnance Survey had carried out a megalithic survey, beginning in 1949, with its first two volumes published in 1961 and 1964, field survey by the Office of Public Works was begun in the late 1960s although no results were published (Haworth 1975). Despite the provision for the publication of lists of National Monuments in Iris Oifigiúil in the 1954 Amendment, there was not a statutory requirement for the publication of archaeological surveys. In 1982, however, the Minister for Finance made provision for the Commissioners of Public Works to initiate and publish countrywide surveys and to compile a Sites and Monuments Record (Power 1993, 137). In 1987, a further amendment was made to the existing legislation with the National Monuments (Amendment) Act, 1987. The Act included provision for new definitions, such as ‘archaeological areas’, defined as:

‘an area which the Commissioners consider to be of archaeological importance but does not include the area of a historic monument standing entered in the Register’ and a new definition of the term historic monument to include:

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‘a prehistoric monument and any monument associated with the commercial, cultural, economic, industrial, military, religious or social history of the place where it is situated or of the country and also includes all monuments in existence before 1700 A.D. or such later date as the Minister may appoint by regulations’. The 1987 Amendment included restrictions on the use of detection devices, provision for historic wrecks, and the enactment of a Historic Monuments Council to advise the minister on the execution of his/her powers. The 1987 Amendment further revised the existing definitions in the 1930 Act and 1954 Amendments. The definition of monument was extended to include:

‘the following, whether above or below the surface of the ground or the water and whether affixed or not affixed to the ground–(a) any artificial or partly artificial building, structure or erection or group of such buildings, structures or erections, (b) any cave, stone or other natural product, whether or not forming part of the ground, that has been artificially carved, sculptured or worked upon or which (where it doesnot form part of the place where it is) appears to have been purposely put or arranged in position, (c) any, or any part of any, prehistoric or ancient–(i) tomb, grave or burial deposit, or (ii) ritual, industrial

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or habitation site, and (d) any place comprising the remains or traces of any such building, structure or erection, any such cave, stone or natural product or any such tomb, grave, burial deposit or ritual, industrial or habitation site, situated on land or in the territorial waters of the State, but does not include any building, or part of any building, that is habitually used for ecclesiastical purposes’. In 1994, the Act was further amended with the National Monuments Amendment Act 1994. This included a provision for the state’s ownership of archaeological objects. The definition of archaeological objects was further revised by the Heritage Act, 1995. In this Act:

‘… archaeological object means any chattel whether in a manufactured or partly manufactured or an unmanufactured state which by reason of the archaeological interest attaching thereto or of its association with any Irish historical event or person has a value substantially greater than its intrinsic (including artistic) value, and the said expression includes ancient human, animal or plant remains’. The Act included a definition of the term ‘archaeology’ as:

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‘the study of past human societies, either as a whole or of various aspects of them, through the material remains left by those societies and the evidence of their environment, and includes the study of, searching and prospecting for: (a) archaeological objects, (b) monuments, (c) buildings, or parts of any buildings, habitually used for ecclesiastical purposes, (d) landscapes, (e) seascapes, (f) wrecks, (g) climatological, ecological, geological or pedological factors which may be relevant to the understanding of past human societies or the distribution or nature of any of the foregoing’. Two years later the National Cultural Institutions Act, 1997 was passed and included the definition of an archaeological object as to include ‘… ancient human, animal or plant remains’. In the same year the European Convention on the Protection of Archaeological Heritage (1992) was ratified by the Oireachtas. This required that steps were taken by the state to ensure that excavations and prospections be carried out using non-destructive methods where possible, and that excavations be carried out by qualified authorised persons. In 1998, the government’s various natural and built heritage functions were brought together within the Department of Arts, Heritage, Gaeltacht and the Islands under the aegis of Dúchas–the Heritage Service. In the same year, the Turf Development Act, 1998 included Article 56: ‘The Company and each subsidiary shall ensure that its activities are so

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conducted as to afford appropriate protection for the environment and the archaeological heritage’. Legal protection and a statutory basis for various inventories of monuments and buildings were provided for under the 1999 Architectural Heritage (National Inventory) and Historic Monuments (Miscellaneous Provisions) Act, 1999. Since June 2003, responsibility for built heritage in the Republic of Ireland was brought under the jurisdiction of the newly formed Department of Environment, Heritage and Local Government.

Heritage Legislation and Environmental Archaeology As the previous sections have demonstrated, the existing legislative apparatus in Northern Ireland and the Republic of Ireland provides little specific provisions with regard to ‘environmental archaeology’. To understand the position of environmental archaeology within the available legislative instruments, it is necessary to examine where heritage legislation is relevant to the protection, retention and study of the materials required for the practice of environmental archaeology. In Northern Ireland the definition of an archaeological object under the 1995 Order includes:

‘any object, being a chattel (whether in a manufactured or unmanufactured state), which is, or appears to be, of archaeological or historical interest and which has, by reason of such interest, a value

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substantially greater than its intrinsic value or the value of the materials of which it is composed’. Under this definition, a case could be made for this definition to include any and all archaeological materials under the criterion ‘unmanufactured state’ as qualified by ‘… of archaeological interest … substantially greater than its intrinsic value …’. As archaeological excavation is carried out under licence in Northern Ireland, the retention of suitable materials for study can be considered as being addressed in the advice notes on sampling in the Environment and Heritage Services Excavations Standards Manual (Archaeological Excavation Unit 2000, 13). The study of environmental archaeology itself, and the application of relevant techniques, are moderated by peer review rather than any legislative provision. In the Republic of Ireland the definition of an archaeological object has incorporated specific reference to ‘plant remains’ since the 1994 Amendment, which contains the definition of ‘archaeology’ as including:

‘climatological, ecological, geological or pedological factors which may be relevant to the understanding of past human societies or the distribution or nature of any of the foregoing’. This definition implicitly recognises environmental archaeology as being intrinsic to the ‘study of past human

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societies’ and provides it with a specific constitutional basis. Under the EC directive Council Regulation (EC) Number 1257/1999 on support for rural development from the European Agricultural Guidance and Guarantee Fund and amending and repealing certain legislation and the Turf Development Act, 1998, legislative provision can be claimed for areas, such as wetlands, of particular significance to environmental archaeology. As archaeological excavation is carried out under licence in the Republic of Ireland, the retention of suitable materials for study can be considered as being regulated through the general protection afforded to archaeological materials under the National Monuments Amendment Act 1994. As in Northern Ireland, the study of environmental archaeology and the application of relevant techniques is moderated by peer review rather than any legislative provision.

The Reality of Environmental Archaeology in Ireland The legislative framework for archaeology in both Northern Ireland and the Republic of Ireland is reasonably similar and has developed along parallel lines. The definitions of terms such as ‘monument’ and ‘archaeological object’ are more or less the same in both Northern Ireland and the Republic of Ireland, although the definition of ‘archaeological object’ in the latter also explicitly refers to materials that relate to ‘climatological, ecological, geological or pedological factors’. In both jurisdictions, regulation of the collection of the materials required for the practice of environmental archaeology is provided by the licensing system for archaeological excavations.

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Archaeology has developed along similar lines in Northern Ireland and the Republic of Ireland since the failure to extend the brief of the Royal Commission to Ireland in 1908. This act retarded the development of archaeological surveys in both jurisdictions after partition since the existing status quo was largely maintained (Power 1993, 137). While an archaeological survey was initiated in Northern Ireland in 1950, it has as yet only produced a single county volume. This situation is in contrast to the archaeological survey in the Republic of Ireland, which has produced a series of volumes since 1982, although a substantial number of these are inventories and some have been independently produced. A licensing system for excavations was developed on both sides of the border, under the National Monuments Act 1930 in the Republic of Ireland and the Ancient Monuments Act (Northern Ireland) 1937 in Northern Ireland. Within this system, applicants must provide a method statement outlining their proposed excavation strategy. In both jurisdictions, the licensing system is the most effective regulatory apparatus for establishing baseline standards for excavation. The scope and number of licensed excavations has increased exponentially, from 13 in Northern Ireland and 110 in the Republic of Ireland in 1990, to 67 in Northern Ireland and 1030 in the Republic of Ireland in 2000. This is significant since the majority of these excavations arise from the ‘polluter pays’ principle of developer funding. Under the planning process in both Northern Ireland and the Republic of Ireland, the identification of a threat to archaeological materials, and the subsequent issuing of planning permission subject to certain conditions, is the primary mechanism by which excavations are initiated. In

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both instances, the regulatory authorities (Environment and Heritage Service: Built Heritage and the Department of Environment, Heritage and Local Government) are responsible for overseeing this process. While the polluter pays principle is in effect in the Republic of Ireland (as it is in England under PPG16 and under regional variants in Scotland and Wales), ambiguities in Planning Policy Statement No. 6: Planning, Archaeology and the Built Heritage have presented difficulties in extending this principle to Northern Ireland. The result of this has been the relative disparity in excavations between Northern Ireland and the Republic of Ireland, although, how far this reflects differing rates of development is unknown. Neither, has an estimate been made of the relative success of each regulatory mechanism for ensuring that adequate provision is made for archaeological materials during the planning process. Where a licence application has taken place in the Republic of Ireland, the inclusion of environmental archaeology is implicit, but not explicit, within this process. In the consultation document–New initiatives for procedures and practices in archaeological licensing–no direct reference is made to environmental archaeology in the Method Statement Template, yet the Site Visit Checklist includes specific questions with regard to the presence of organic remains and whether environmental samples are being taken (Dúchas 2001, 56). In Northern Ireland, in the Environment and Heritage Services excavations manual it is stated that: ‘The decision to sample will rest with the excavator and/or the environmental co-ordinator, possibly implementing a sampling strategy agreed in advance’ (Archaeological Excavation Unit 2000,

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13). It also lists categories of specialist disciplines a director may need to call upon, including animal bone, human remains, soil analysis and wood analysis (Archaeological Excavation Unit 2000, 15). In the context of environmental archaeology, it is notable that pollen analysis, plant macrofossil analysis (charred/ waterlogged), mollusc analysis and insect analysis are absent from this list. The problems of adequate reporting of excavation results should briefly be addressed at this point, particularly with reference to studies that seek to establish the amount of unpublished material (Lambrick and Doyle 2000). While the process of enumerating the level of unpublished excavation reports in Ireland has begun, there has been no monitoring of the scope of unpublished reports relevant to environmental archaeology. As such, no assessment can be made of the extent of good practice, with regard to environmental archaeology, and general archaeological excavation strategies as agreed during the licensing process. Such an assessment would require an understanding of both the potential for environmental study as presented by the archaeological materials present, and, a measure of the extent to which such work was actually undertaken. This study is needed to substantiate any claims with regard to effectiveness, or otherwise, of both the existing legislation and its primary regulatory apparatus, the licensing system, for the practice of environmental archaeology in Ireland. In summary, it must be noted that while technical and academic standards in environmental archaeology in Ireland can be adequately moderated through peer review and debate, the legislative protection given to the materials of most interest to such work is explicit in the Republic of Ireland but

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non-specific in Northern Ireland. In both jurisdictions, the licensing system for archaeological excavations provides a safety net whereby threats to soils and other materials that can be employed in environmental archaeology studies can be identified and mitigated. The legal impetus to engage in the study of environmental archaeology as part of this work lies solely with the conditions under which the licences for archaeological excavation are issued.

Legislation and Policy Documents Referred to in the Text Pre-partition — Ancient Monuments Protection (Ireland) Act of 1882

Northern Ireland: 1921–present — Ancient Monuments Act (Northern Ireland) 1926 — Ancient Monuments Act (Northern Ireland) 1937 — Historic Monuments Act (Northern Ireland) 1971 — Protection of Wrecks Act 1973 — Planning (Northern Ireland) Order 1991 — A Planning Strategy for Rural Northern Ireland in 1993 — Access to Environmental Information Regulations (Northern Ireland) 1993 — Historic Monuments and (Northern Ireland) Order 1995 — Merchant Shipping Act 1995

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Archaeological

Objects

— Treasure Act 1996 — Planning Policy Statement No. 6: Planning, Archaeology and the Built Heritage — Regulation (EC) Number 1257/1999 on support for rural development from the European Agricultural Guidance and Guarantee Fund and amending and repealing certain legislation

Saorstát Eireann/Irish Free State: 1921–1937; Éire: 1937–1949; The Republic of Ireland: 1949–present — National Monuments Act 1930 — National Monuments (Amendment) Act, 1954 — National Monuments (Amendment) Act, 1987 — European Convention on the Protection of Archaeological Heritage (1992) — National Monuments Amendment Act 1994 — Heritage Act, 1995. — National Cultural Institutions Act, 1997 — Turf Development Act, 1998 — Architectural Heritage (National Inventory) and Historic Monuments (Miscellaneous Provisions) Act, 1999

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References An Roinn Ealaíon, Oidhreacta, Gaeltachta agus Oileán 1999. Framework and Principles for the Protection of the Archaeological Heritage. Dublin: Stationery Office. Archaeological Excavation Unit 2000. Excavations Standards Manual. Belfast: Environment and Heritage Service Publication Unit. Brannon, N. 2002. The role of the Environment and Heritage Service in Northern Ireland archaeology. Antiquity 76, 493–7. Dúchas 2001. New initiatives for procedures and practices in archaeological licensing. An Roinn Ealaíonn, Oidhreachta, Gaeltachta agus Oiléan consultation document. Foley, C. 2002. The contribution of agricultural support measures to protecting the archaeological heritage of Northern Ireland, pp. 117–24 in Fairclough, G. and Rippon, S. (eds.), Europe’s Cultural Landscape: Archaeologists and Management of Change. Europa Archaeologiae Consilium, Occasional Paper 2, Council of Europe. Hamlin, A. 1992. Archaeological survey in Northern Ireland, pp. 41–4 in Royal Commission on Historic Monuments (England), Inventories of monuments and historic buildings in Europe. Proceedings of the Colloquium Held in Oxford (England) in 1988. London: RCHME. Haworth, R. 1975. Archaeological field survey in Ireland–past, present, future. Irish Archaeological Research Forum 2, 7–19.

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Lambrick, G. and Doyle, I. W. 2000. Review of Archaeological Assessment and Monitoring Procedures in Ireland. Kilkenny: Heritage Council Publication. Power, D. 1993. Archaeological survey in the Republic of Ireland and the Cork experience, pp. 137–9 in Shee Twohig, E. and Ronayne, M. (eds.), Past Perceptions: The Prehistoric Archaeology of South-West Ireland. Cork: Cork University Press.

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