Geology and Solid Earth Geophysics of the Pacific Basin: Report of the Standing Committee 9780824884895

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TENTH PACIFIC SCIENCE CONGRESS SERIES

TENTH PACIFIC SCIENCE CONGRESS SERIES Tenth Pacific Science Congress, Honolulu, 1961

AGRICULTURE

Soil Conservation in the Pacific—A Symposium and Panel Discussion J. H. Christ, chairman ANTHROPOLOGY

Ryukyuan Culture and Society—A Survey Allan H. Smith, editor BOTANY

Ancient Pacific Floras—The Pollen Story Lucy M. Cranwell, editor ENTOMOLOGY

Pacific Entomology—Report of the Standing Committee Chairman J. J. H. Szent-Ivany GEOLOGY

Geology and Solid Earth Geophysics of the Pacific Basin— Report of the Standing Committee Gordon A. Macdonald, chairman MARINE BIOLOGY

Physical Aspects of Light in the Sea—A Symposium John E. Tyler, editor MEDICINE

Public Health and Medical Sciences in the Pacific—A Forty-year Review J. Ralph Audy, editor

GEOLOGY AND GEOPHYSICS

T E N T H PACIFIC SCIENCE

CONGRESS

of the Pacific Science Association

HOST INSTITUTIONS National Academy of Sciences Bernice Pauahi Bishop Museum University of Hawaii

Honolulu, Hawaii, U.S.A. August 21 to September 6, 1961

UNIVERSITY OF H A W A I I ,

GEOLOGY AND SOLID EARTH GEOPHYSICS OF THE PACIFIC BASIN Report of the Standing Committee GORDON A . MACDONALD Chairman

UNIVERSITY OF HAWAII PRESS Honolulu, Hawaii, 1963

Copyright 1963 University of Hawaii Press Library of Congress Catalog Card Number: 63-13253

PUBLISHER'S PREFACE The papers published in this volume were presented at the Tenth Pacific Science Congress of the Pacific Science Association held August 21 to September 6, 1961, on the campus of the University of Hawaii, Honolulu, Hawaii, U.S.A., scene of the first meeting. The Congress was sponsored jointly by the National Academy of Sciences, Bernice Pauahi Bishop Museum, and the University of Hawaii. The publisher is indebted to the chairman for having assembled these papers from the far corners of the Pacific. In editing the material, American usage has been followed in the main, though the desire to put this material in print as soon as possible after it was assembled has been responsible for some degree of stylistic inconsistency. Funds toward the issuance of Tenth Pacific Science Congress papers published by the University of Hawaii Press have been furnished by the Legislature of the State of Hawaii and the National Institutes of Health. It is believed that a useful purpose is served by bringing together in one volume distinguished papers on a common subject as it applies to conditions that prevail in the various countries of this increasingly important segment of the world scene.

vii

STANDING COMMITTEE ON GEOLOGY AND GEOPHYSICS G O R D O N A . MACDONALD,

Australia Geology Geophysics Canada Geology Geophysics

chairman

Bureau of Mineral Resources Canberra Bureau of Mineral Resources Canberra

N . H . FISHER J . M . RAYNBR

Victoria Museum Ottawa University of British Columbia Vancouver

G . B . LEECH J . A . JACOBS

Chile Geology and Geophysics

HECTOR FLORES W .

Universidad de Chile Santiago

China Geology and Geophysics

V . C. J U A N

National Taiwan University Taipei

El Salvador Geology and Geophysics

FRITZ D U R R

Servicio Geologico Nacional San Salvador

J O H N KATILI

University of Indonesia Bandung Dartmouth College Hanover

Indonesia Geology Geophysics Japan Geology Geophysics

ROBERT W . DECKER

T E I I C H I KOBAYASHI T S U N E J I RIKITAKE

University of Tokyo Tokyo University of Tokyo Tokyo

Malaya Geology and Geophysics

J . B . ALEXANDER

Geological Survey Batu Gajah

Mexico Geology and Geophysics

M . MALDONADO-KOERDELL

Instituto Pan-Americano de Geografia e Historia Mexico City

R . S. A L L A N

Canterbury University Christchurch Department of Scientific and Industrial Research Wellington

New Zealand Geology Geophysics

Philippines Geology and Geophysics

E . I. ROBERTSON

University of the Philippines Quezon City

ARTURO ALCARAZ

viii

Thailand Geology and Geophysics United States Hawaii Geology and Geophysics Pacific Basin Geology and Geophysics U.S. Trust Territory Geology and Geophysics

SAMAN BURAVAS

Royal Department of Mines Bangkok

G O R D O N A . MACDONALD

University of Hawaii Honolulu

EDWIN L. H A M I L T O N

Naval Electronics Laboratory San Diego

CHARLES G . J O H N S O N

U.S. Army Engineers Honolulu

Western Pacific High Commission Territories Geology and

Geological Survey Department British Solomon Islands Protectorate

J. C. GROVER

Geophysics

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REPORT OF THE STANDING COMMITTEE ON GEOLOGY AND GEOPHYSICS PACIFIC SCIENCE ASSOCIATION T E N T H PACIFIC SCIENCE CONGRESS

An attempt has been made to expand the Standing Committee on Geology and Geophysics to include representatives of Pacific border countries not previously represented, and it is with pleasure that I report that Chile, El Salvador, and Mexico are now represented on the Committee. The U.S.S.R. was requested to name members to the committee but, I regret to say, did not do so. Due to the rapid expansion of both major branches of solid earth sciences, particularly geophysics, during recent years, it has seemed advisable to appoint a representative in each branch from the larger countries and those in which work has been very active. On this, the occasion of the first repeat meeting of the Congress in any country, constituting in a sense the end of a cycle, it was decided that it would be appropriate to take stock of the progress we have made, to see wherein the work of the past has been adequate and where it has been deficient, and to see what appear to be the most urgent and promising paths to follow in the immediate future. Accordingly, each member of the committee was asked to write a brief summary account of the progress of geology or geophysics, or both, in his country since the first meeting of the Pan-Pacific Science Congress in Honolulu in 1920, and to include a critical appraisal of the work done and suggestions for the future. All members of the Committee agreed to do this—a very considerable task in the case of large countries where much work has been

accomplished. Most members have submitted their reports. Those who have not done so no doubt have been prevented by the pressure of other work in a most hectic age. Circumstances forced Dr. A. R. Ritsema to resign from the Committee, but a report on geophysics in Indonesia has kindly been supplied by Dr. Robert Decker, of Dartmouth College, who recently returned from a year's geophysical work in that country. The reports follow, in alphabetical order according to countries. It seems to me that they are of much interest, indicating as they do not only the progress in geologic knowledge of the Pacific area, but the changes in working techniques that have taken and are taking place. Some of them read like stories of high adventure, as indeed they are—not only the adventure of exploring primitive and often savage lands little touched by civilization, but as part of the equally exciting adventure of exploring the unknown areas of knowledge of our planet. In editing the individual chapters for inclusion in the present report, two aspects have struck me with great force: how far we have come in the past 40 years, and how very far we have yet to go. I want to take this opportunity to thank all of the members of the Committee who have labored so hard to produce this report.

Gordon A. Macdonald Chairman

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CONTENTS PAGE

Introduction Standing Committee

GORDON A. MACDONALD

x

Report Australia Geology

N. H. FISHER

Geophysics

J . C. JAEGER and R . F. T H Y E R

15

3

Canada Geology

G. B. LEECH

27

Geophysics

J. A. JACOBS

39

China Geology and Geophysics

V. C. JUAN

47

FRITZ D U R R

53

Geology

JOHN KATILI

55

Geophysics

ROBERT W . DECKER

69

El Salvador Geology and

Geophysics Indonesia

Japan Geology

TEIICHI KOBAYASHI

79

Geophysics

T S U N E J I RIKITAKE

81

J. B. ALEXANDER

89

M. MALDONADO-KOERDELL

97

Malaya Geology and

Geophysics Mexico Geology and

Geophysics New Zealand Geology

R. S. ALLAN

103

Geophysics

E. I. ROBERTSON

109

ARTURO ALCARAZ

115

Philippines G e o l o g y and

Geophysics

xi

Thailand Geology and Geophysics

SAMAN BURAVAS

United States Hawaii Geology and Geophysics Pacific Basin Geology and Geophysics U.S. Trust Territory Geology and Geophysics Geophysics

GORDON A. MACDONALD

EDWIN L. HAMILTON

CHARLES G. JOHNSON DONALD E. W H I T E

Western Pacific High Commission Territories Geology and

Geophysics

J. C. GROVER

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Advances in Geology in Australia Since 19201 N . H . FISHER 2

Oil exploration between the wars was generally at a low level, except for occasional bursts of activity such as that by the Shell organization in Queensland in the early forties, and various geological surveys made in New Guinea, especially in Papua, in the years immediately before World War II. For a period after the war, geological progress was hampered by lack of trained personnel. Very few people had taken degree courses in geology during the war. When this deficiency was remedied, or partly remedied, a remarkable increase in geological activity occurred. The Commonwealth Government's Bureau of Mineral Resources, Geology and Geophysics came into existence and began, among other things, systematic geological mapping and the production of a series of four-mile geological maps. Other major developments were the building up of the South Australian Geological Survey from two or three geologists to a well-equipped and capably staffed organization with about 40 geologists, a general increase in the staffs of most State Geological Surveys, and the establishment of geology schools in the universities of Tasmania at Hobart, of New South Wales at Sydney and Newcastle, and of New England at Armidale, New South Wales, and later in Canberra, Australian Capital Territory, and Townsville, North Queensland. Mining companies began to employ geological staffs and several of the larger companies set up exploration departments. The uranium boom in the early fifties, followed by a great increase in oil exploration subsequent to the discovery of oil at Rough Range, Western Australia, in 1953, resulted in further large-scale employment of geologists.

GENERAL REVIEW I N AUSTRALIA, THE PERIOD f r o m 1 9 2 0 t o t h e

present is split by World War II into two sharply contrasting periods with respect to advances in knowledge of the geology of the continent. Between the two world wars geological work was almost entirely restricted to the Geological Surveys and universities of the six states. The official Geological Surveys were more and more confined to routine and ad hoc tasks, such as examination of mines and prospects, siting water bores, and giving assistance to prospectors and the mining industry generally. Comparatively little systematic mapping was done and funds for publication were very limited. An exception was the geological investigation of mining areas and prospects by the Aerial, Geological and Geophysical Survey of Northern Australia, which was set up by the Commonwealth Government and the Governments of Queensland and Western Australia and operated from 1935 to 1940. Few, if any, mining companies employed geologists until about 1930, when Mt. Isa Mines, Ltd., commenced operations and maintained a full-time geological staff. Some of the other larger companies later followed suit, but only after the war did geological departments come to be regarded as a normal and essential part of a mining company's operations. Published with the approval of the Director, Bureau of Mineral Resources, Geology and Geophysics, Canberra, Australia. 2 Bureau of Mineral Resources, Geology and Geophysics, Australia.

3

4 Another avenue of increasing recognition of the need for geological services was in the application of geology to engineering projects of various kinds. During the past ten years, the Geological Society of Australia has been established. Its publication, Journal of the Geological Society of Australia, was first issued in 1954 and has since included comprehensive volumes on the geology of Western Australia, South Australia, and Queensland. Comparable volumes on other states are being compiled. The Society has also been responsible, through one of its committees, for the preparation, in collaboration with the Bureau of Mineral Resources and the State Geological Surveys, of a recently published Tectonic map of Australia and for maintaining an Australian code of stratigraphical nomenclature. At the present time the membership of the Geological Society, which comprises the great majority of the practicing geologists in the country, is about seven hundred. Two important factors which contributed to the increase in geological work after the war are, first, the use of aerial photographs in geological mapping and map compilation, and, second, the use of four-wheel-drive vehicles for mapping once relatively inaccessible country. An interesting recent development is the inauguration by the geophysical department of the Australian National University at Canberra of an age determination laboratory. This also is being operated as a combined project with the Bureau of Mineral Resources, which has for some time been collecting and concentrating samples of granites and other suitable rocks. The actual dating program by the potassium/ argon method has only recently begun, but it is expected that results obtained during the next few years will be of tremendous assistance in solving outstanding geological problems, especially in dating and correlating the PreCambrian. GEOLOGICAL MAPPING

During the period 1920 to 1945, geological mapping was carried out mainly by the State Geological Surveys and by the geological departments of the universities. Maps were pub-

lished of isolated areas, and Tasmania and Western Australia produced new editions of the State Geological Map. The most important single contribution to geological map production during this period was the publication in 1932 of a Geological Map of the Commonwealth of Australia (scale 48 miles to 1 inch), compiled by T. W . Edgeworth David, with explanatory notes. This has been until recently the standard reference map of Australian geology. Since the war, revisions of the State Geological Maps have been produced as follows: Tasmania, 1947, 1 inch: 16 miles; Queensland, 1953, 1 inch:40 miles; South Australia, 1953, 1 inch: 40 miles; Victoria, 1955, 1 inch: 16 miles; and Western Australia, 1957, 1 inch:40 miles. The Bureau of Mineral Resources has printed geological maps of Australia on scales of 1 inch: 100 miles, 1953; and 1:6,000,000, 1959; and a Tectonic Map of Australia, 1 inch:40 miles, I960; also mineral maps on scales of 1 inch:75 miles and 1:6,000,000. Since the war, the Bureau of Mineral Resources and several of the states have been producing colored geological maps. A cooperative scheme exists for the production of fourmile maps with standard color scheme and geological conventions and layout, and the Bureau, South Australia, and Tasmania are also producing one-mile maps. All of these geological map sheets correspond to the quadrangles of the Australian National Grid. Recently it has been agreed that to maintain conformity with international practice, base maps and geological maps of the "four-mile" areas would be produced at the scale of 1:250,000. The status of geological map production in April, 1961, is shown in Figure 1.

GEOLOGY OF MINES AND MINERAL FIELDS

The last 40 years, and particularly the 15 years since World War II ended, have been marked by very great advances in the scope and the techniques of mineral field mapping and the search for mineral deposits. The importance of the mining geologist has been realized not only in the search for new deposits but in the

FIG. 1. Geological mapping, Australia, showing published geological maps, April, 1961.

6 elimination of wasteful developmental and exploration practices. A change has been made from the predominantly descriptive and generalized geology of the nineteen-trwenties to detailed structural analysis of ore controls coupled with increasing emphasis on sedimentary influences. Enlarged aerial photos are used for mapping of surface outcrops and much use is made of ore microscopy, geophysics, and geochemistry. Between 1920 and the mid-1950s company investigations were mainly restricted to examination of mining properties; a notable exception was the Central Geological Survey of the Broken Hill district, 1936-39. In the late 1930s the Aerial, Geological and Geophysical Survey of North Australia engaged in a vigorous program of mapping of selected Northern Australian mining fields. They made extensive use of aerial photographs and of geophysics, but generally restricted their work to fairly small mineralized areas. Since 1946 the combined impact of high base metal prices, the strategic importance of uranium, and a policy of planned national development has resulted in greatly expanded mapping activity. The Commonwealth Bureau of Mineral Resources, Geology and Geophysics has made the largest individual contribution and has mapped all or part of many of the known mineral-bearing areas in the northern part of Australia. It has also carried out extensive geophysical work and some geochemical prospecting. The State Surveys have also done considerable work, and mapping by university workers has continued. N o t all the results obtained have been published to date. A notable feature of recent years has been the amount of geological mapping and geophysical investigation carried out by mining and prospecting companies. The universities have also contributed to the search for minerals by their laboratory research and by the establishment, in several states, of chairs of applied geology. Additional laboratory services have been established with the expansion of field investigations: the Commonwealth Scientific and Industrial Research Organisation Mineragraphic Section and the Australian Mineral Development Laboratories (formerly part of the South Australian

Mines Department and now financed jointly by industry and the South Australian and Commonwealth Governments) should particularly be mentioned. In recent years there has been a growing awareness that classical theories of ore genesis and control are inadequate, particularly that structure is not the sole determining factor in the localization of ore bodies. With this awareness has come a greater appreciation of the value of stratigraphic mapping and of the need to understand the depositional and tectonic environment of the host rocks of ore bodies, and of the ore bodies themselves. As a result, particularly of the post-World War II work, the geology, palaeogeography, and tectonics of large areas of mineral-bearing igneous, metamorphic, and sedimentary rocks are much better known than before. Considerable progress, for example, has been made in the subdivision of the Pre-Cambrian. Several important mineral deposits and fields have been discovered in the period under review. Some of the discoveries have been the direct result of regional mapping and prospecting by large organizations, public and private. Notable among the discoveries since 1920 are the Mount Isa silver-lead-zinc and copper ore bodies, the bauxite deposits of Arnhem Land and Cape York Peninsula, the beach sand deposits of southeastern Queensland and northeastern N e w South Wales, the Tennant Creek gold field and later its copper deposits, lead-zinc deposits of the Macarthur River area, Northern Territory, Rum Jungle and South Alligator uranium fields, lead-zinc deposits of Brown's lode, near Rum Jungle, Mary Kathleen uranium deposit in northwest Queensland, a number of gold deposits, mainly in Western Australia, and the iron deposits of northwestern Queensland and Tasmania, and new areas in Western Australia. In addition, many deposits in various parts of the country, though mineralization was known earlier, were first developed extensively in the period under review, e.g., K i n g Island scheelite, and Aberfoyle tin-tungsten in Tasmania. Only since the war has it become the rule for mining companies to maintain geological departments. In nearly all mines now geologists

7 carry out systematic and detailed underground mapping, prepare and keep up-to-date cross and longitudinal sections, and compile assay and structure contours of ore deposits. Use of these techniques and of the diamond drill has resulted in the discovery of new ore and extensions of existing ore. Accurate geological maps can be found in the offices of most mining companies. Several of the larger companies have an exploration department or a subsidiary exploration company. Much ore is being won from the "abandoned" upper levels of mines after detailed geological analysis. New gold shoots were discovered in the Mararoa vein at Norseman, Western Australia, by the application of structural geology. Detailed surface mapping helped to find Mt. Isa's northern lead-zinc deposit. Surface and underground diamond drilling outlined Mt. Isa's chalcopyrite-pyrite-dolomite ore body. At Peko and Noble's Nob mines at Tennant Creek structural geology and diamond drilling found extensions of copper-gold and gold ore. Surface studies and drilling contributed to the proof of extensive open cast coal deposits particularly at Muswellbrook, New South Wales. In New Guinea it was established that a study of gold fineness could give an important lead to the source of the gold. Extensive rutile-zircon-ilmenite deposits were found on the east coast of Australia between Brisbane and Newcastle. Significant increases in lead and zinc reserves at Broken Hill were found in 1953. PETROLEUM GEOLOGY

Our knowledge of the sedimentary basins has increased in the last 40 years and particularly during the post-World War II period. Before the war much of the field work consisted of reconnaissance trips or examination of local sections. According'y there were deficiencies in the reporting of sequences and the relation to them of fossil collections. Fossils accumulated at far too great a rate for detailed examination and description to keep pace with them, because of the very small number of workers in palaeontology. Not enough attention was given to the regional structure and geological history of the sedimentary basins.

Since the war considerable advances have been made, some of them piecemeal and haphazard, but several, particularly in Western Australia, due to systematic mapping, followed up by more detailed investigation and some drilling. Much, however, remains to be done. Developments in knowledge during the period under review include the establishment of the existence of Cambrian marine sediments in the Georgina Basin, Amadeus Basin, and Bonaparte Gulf Basin ( Figure 2 ) ; Ordovician in the Georgina Basin, Amadeus Basin, and Canning Basin; Silurian in the Carnarvon Basin; Devonian (lacustrine) in the Georgina, Carnarvon, and Fitzroy Basins; Carboniferous in the Bonaparte Gulf, Fitzroy, and Carnarvon Basins; Permian in the Great Artesian Basin and Murray Basins; Triassic in the Perth and Fitzroy Basins; Jurassic in the Carnarvon Basin; Cretaceous in the Canning, Carnarvon, Eucla, Murray, and Otway Basins; Eocene in the Carnarvon, Perth, Eucla, St. Vincent, Otway, and Gippsland Basins; Miocene in the Carnarvon, Eucla, Murray, Otway, and Gippsland Basins and off the east coast of Queensland. The Officer Basin was discovered by geologists from outcrop and by aeromagnetic reconnaissance. To date it is known to contain Proterozoic and Ordovician sediments. The outcrop margins of the Carnarvon, Perth, and Georgina Basins are known. The regional structure of most of the sedimentary basins is not known, although some are known in part. Until the basin margins are mapped adequately, it cannot be claimed that the full outcrop sequence is established. Until regional structure is known, local structures are of doubtful significance. The other most urgent needs for the future are the adequate description of fossil assemblages properly related to outcrop or subsurface sequences; the determination by seismic surveys and drilling of the regional structure and the related stratigraphy; and the complete and precise geological history of the basins. COAL GEOLOGY

Since 1920 Australian coal geologists have been largely preoccupied in providing for the

8

FIG. 2. Locality map, Australia, showing sedimentary basins.

immediate requirements of the rapidly expanding coal mining industry. This expansion is illustrated in the following production figures (in long tons). Black coal Brown coal

1920 12,800,000 500,000

I960 22,566,000 14,984,000

In the period under review, field mapping has added considerably to the knowledge of the Permian coal measures in the southwestern, western, and northwestern parts of the Main

Coal Province, and also of the Mesozoic coal measures of the Clarence Coal Province in New South Wales and to all of the widely distributed Permian and Mesozoic coal basins of eastern Queensland. This mapping has been concentrated on the location of new seams and delineation of known seams in established coal basins. It has produced little change in the general Permian and Mesozoic stratigraphy. In the more recent work much effort has been directed towards collecting and rationalizing old bore and coal field records and forcing improved

9 drilling standards on the drilling organizations, particularly in the use of the split inner-tubecore-barrel. Geophysical methods have been largely instrumental in establishing reserves in the strategically important concealed coal fields of Collie, Leigh Creek, Yallourn-Morwell, Coorabin, and to a much smaller degree, Ashford and Callide. Both gravity and seismic methods have been used. In the Newcastle area magnetic surveys have been used to locate some of the major igneous dykes. In pure coal research, geologists have worked closely with allied scientists in the fields of coal rank and metamorphism, coal petrography, palynology, moisture content and mineral impurities. The Commonwealth Scientific and Industrial Research Organisation has formed a large Coal Research Section to study the chemical and physical properties of coal. PETROLOGY

During the period 1920-60 Australian penologists, along with those in other countries, have tended to depart from a predominantly descriptive approach to one concentrating much more on genetic aspects. In recent years a number of regional petrological and petrogenetic studies have been undertaken—e.g., a review of Australian charnockites, Pre-Cambrian rocks of South West Australia, scapolitization in the Cloncurry area of Queensland, and dolerite intrusion in Tasmania. Preliminary accounts of metamorphic rocks and metamorphism in the Cloncurry-Mt. Isa area have been published, and basic rocks and granites have been studied in somewhat greater detail. Reviews of igneous activity in certain epochs and periods have been published. Several years ago an Australia-wide program of collection of granite samples for age determination was begun. A compilation of all chemical analyses of Australian rocks available to the end of I960 is being made; a complete bibliography will accompany this compilation. In addition to such broad-scale studies, numerous investigations of more restricted scope have been undertaken. Among the more important are those dealing with differentiation in Tasmanian dolerites, with leucite-lamproites

in Western Australia, and the formation of dolomite in lakes in southeastern South Australia. Petrofabric studies have been made on rocks from South Australia, Western Australia, New South Wales, and Tasmania. Palaeomagnetic studies and experimental work on rock deformation were begun in the last decade. Ring complexes have been described from southeastern and northeastern Queensland. Substantial advances in knowledge have been made as a result of the work of geologists attached to authorities developing hydroelectric power in New South Wales, Victoria and Tasmania. Mineragraphic and petrological investigations of many mining properties have been made. Extensive study of the minerals of the Broken Hill lode has brought forward very strong evidence for a metasomatic origin, though some workers, including most of the geologists working in the area, now favor a syngenetic origin for this and other important Australian ore bodies of the bedded type. A number of Australian meteorites has been described, and a study of the structure and chemistry of meteorites in general has placed limits on the size, composition, and structure of a postulated parent meteorite body. Deductions as to the nature of the earth's interior have been made from this work. A comprehensive study of the morphology of tektites has demonstrated their extraterrestrial origin. As much of Australia has not been systematically mapped, much scope for petrological and geochemical work, both in metalliferous and non-metalliferous regions, remains. Least attention has been paid to sedimentary petrology; data are needed in this field as an additional tool in the exploration for petroleum. PALAEONTOLOGY

Before World War II palaeontologists in Australia were almost completely confined to the staffs of the geology departments of the universities. Since the war these staffs have been increased, the Bureau of Mineral Resources has set up sections to study both mega-fossils and microfossils, and some of the State Geological Surveys

10 have employed palaeontologists. Even now, however, much of the time of the palaeontologists is largely spent on such activities as teaching and routine determinations for stratigraphic surveys, and taxonomic studies are brief and infrequent. The history of palaeontology in Australia was reviewed by Dr. I. A. Brown in a presidential address to the Linnean Society of New South Wales in 1946. The search for oil in the succeeding period has brought about an unprecedented demand for detailed stratigraphic and palaeogeographic data as regional mapping and stratigraphic drilling proceed, and the known distribution of rocks of almost every system has been greatly modified. Correlation has been greatly improved by additional discoveries of Swedish Cambrian index agnostid trilobites in Queensland, Tasmania, and the Northern Territory; graptolites in shelly Ordovician of all states and in the shelly Silurian of Queensland, New South Wales, and the Australian Capital Territory; and brachiopods, supplementing the earlier discoveries of ammonoids, in the Devonian of Western Australia. As a result, detailed palaeogeographic maps have been published for part of the Cambrian Period, and a more exact dating of Lower Palaeozoic orogenies has been achieved. Animal groups not previously recognized in Australia include eurypterids and carpoid echinoderms in the Silurian and Devonian of Victoria. South Australia has yielded two remarkable faunas—primitive invertebrates in the late Pre-Cambrian or Early Cambrian of the Ediacara area, and pre-Recent vertebrates in the Lake Eyre area. As regards the Foraminifera, Permian and Cretaceous assemblages have been closely studied and are now of considerable importance in surface and subsurface investigations. The Tertiary sequence is well controlled by both the larger and smaller species. Upper Devonian Foraminifera were found for the first time in 1958. Conodonts were first discovered in Australia in 1943 in Ordovician rocks in Central Australia. They are now being found in abundance in the Devonian as well as the Ordovician. The

study of ostracods has advanced considerably. This group is proving useful in the otherwise unfossiliferous rocks in some of the surface and subsurface beds of Lower Carboniferous and Upper Devonian age in Western Australia. Microplankton investigations began in 1946 with the study of the Tertiary deposits of Australia. This work has been extended through the greater part of the geological column, and many excellent assemblages have been obtained from Ordovician sediments in deep bores in Western Australia. Spores and pollens were first used in a study of the Permian coals of New South Wales. These microfossils have now become of considerable importance in the correlation of the Permian, Mesozoic, and Tertiary of both Eastern and Western Australia, and have proved, together with the microplankton, the most useful method of dating the otherwise unfossiliferous beds penetrated by oil bores in various parts of the continent. A comprehensive study of the history of micropalaeontology in Australia by Dr. Irene Crespin was published in the Journal of the Royal Society of New South Wales in 1959. The present state of knowledge with respect to megafossils may be summarized as follows: Cambrian: Correlation and palaeogeography are satisfactory for Middle and early Upper Cambrian, less so for the remainder. Of an estimated 600 species about a quarter are described—many archaeocyathids, hydroids, a few brachiopods and molluscs, and a number of trilobites. Ordovician: Graptolitic sequences of southeastern Australia are well known; correlation of the shelly sequences is handicapped by the large number of undescribed genera and species. Silurian: Correlation is established wherever graptolites occur; it is less satisfactory in sequences containing shelly fossils only. Apart from corals, knowledge of the faunas is imperfect. Devonian: Correlation is considered to be satisfactory, especially in Western Australia. Taxonomy is most active in Queensland, Victoria, and Western Australia. Carboniferous: The succession in Eastern

11 Australia is known from studies of corals, brachiopods, molluscs, trilobites, and plants. Studies on Western Australian faunas are in hand, and papers on brachiopods have recently appeared. Permian: This is the best known Australian system. Correlation is provided by invertebrate faunas in general. Fossils are described from all states. Triassic and Jurassic: Fresh-water sequences of Eastern Australia are the best known. Fossils include molluscs, many insects and plants, and some vertebrates. Cretaceous: Described fossils from the fresh-water and marine sequences of all states include sponges, many molluscs, arthropods, echinoderms, vertebrates, and plants. Current studies on invertebrates, especially from Western Australia and the Northern Territory, indicate that many species are undescribed. Correlation is facilitated by the identification of some extra-Australian species among the molluscs. Tertiary and Quaternary: Representatives of all phyla are described from fresh-water and marine sequences, though not all groups are equally exploited. Correlation is not everywhere clear, particularly in the freshwater and terrestrial sequences. Problematica: A few studies have appeared on stromatolitic algae and on tracks and trails in Proterozoic and Phanerozoic rocks. The vast bulk of the fossils is undescribed. Present shortcomings are mainly the large backlog of taxonomic work, due to the small number of workers, aggravated by inadequate laboratory facilities and scarcity of technicians, though progress is being made, especially in the upper Palaeozoic. Badly needed are an annotated bibliography of palaeontological literature, a catalogue of species, a catalogue of type specimens and a textbook of Australian fossils for teaching purposes. HYDROGEOLOGY

Prior to 1920, interest in groundwater in Australia was concentrated on the artesian

basins, particularly on the Great Artesian Basin, where there was active research into the origin of the water and the causes of diminution of flow. Since 1920, development of the major artesian basins has continued and there has been a marked increase in efforts to locate and develop the smaller groundwater occurrences. Much of this development has been undertaken at private initiative, without hydrogeological investigation, and the majority of the investigations made have been to locate and develop supplies for immediate requirements. During the period 1920-60 there has been considerable success in locating and developing groundwater supplies, particularly in the provision of water over wide areas for stock and domestic use. The use of groundwater for industrial purposes and irrigation is increasing. Reliable hydrological, geological, and chemical data have been recorded from many of the bores drilled, but for thousands of bores little, if any, record exists. The records available and the progress of hydrogeological work in Australia to 1928 are summarized in the reports of the "Interstate Conference on Artesian Water." Since that date hydrogeological work has been continued, mainly by state authorities, and reports have been published on some projects, but no general summaries of progress are available and many bore records are unpublished. Early hydrogeological work in Australia was marked by imaginative investigation and test drilling of new possibilities and a valuable coordination of work by the various authorities. This progressive approach has not, in general, been carried into the stages of development and assessment of groundwater resources. Little detailed research has been done on the application of general hydrological theory to particular areas. Apart from the studies of diminution of flow in the Great Artesian Basin, drainage of groundwater in irrigation areas, and storage in some coastal sands, few quantitative studies have been made. The limits and general stratigraphy of the larger groundwater basins are now known with reasonable accuracy and for most of these basins a simplified picture has been obtained of groundwater occurrence and movement. The general pattern of groundwater occurrence out-

12 side the larger basins has been established, although many individual areas remain virtually untested. Future increase in demand on groundwater resources will require detailed, and quantitative, investigations, particularly of areas where groundwater is used for industrial purposes or irrigation. The surveys must include assessment of recharge to the aquifers in addition to determination of the properties and extent of the aquifers. Essential for progress is the provision and training of an adequate number of hydrogeologists, for which no formal course of training at present exists in Australia.

competent work is done in those organizations where geologists and engineers work in close and regular liaison—a key to efficient use of geology in engineering. Dam site investigations have been the major task for engineering geologists. The use of the split-core barrel to provide complete recovery of diamond drill cores and water-pressure testing of drill holes have become standard practice to minimize interpretation. Geophysical surveys, mainly seismic refraction work to determine the depth of unconsolidated cover or of weathered rock, are also widely used in the investigation of sites for dams, powerhouses and tunnels. In general, engineering geology in Australia seems to be keeping pace with that in other countries.

ENGINEERING GEOLOGY

One of the main problems in engineering geology lies in the training for this special field where the geologist needs sufficient knowledge of engineering to appreciate, broadly, the engineering significance of the data he collects and to report his findings in such a way as to be readily understood and used by engineers. At present the principal training in engineering geology is carried out on-the-job within those organizations u s i n g engineering geology. Courses on the subject are given to students studying economic geology in their degree courses in the universities but there is as yet no comprehensive course on engineering geology either at the undergraduate or postgraduate level.

Engineering geology is a comparatively new branch of the science which is growing up as a link between two disciplines—engineering and geology—in response to an increasing awareness of the value of geology to engineers. Although the value of geology to engineers was clearly seen in some quarters before World War II, organized engineering geology has been a post-war development in Australia, principally in the field of hydroelectric power, but also in other branches of engineering such as water supply, main roads, and the supply of rock for various purposes. The services of engineering geologists are provided in three main ways in Australia: by small engineering geology sections within major engineering organizations such as the Snowy Mountains Hydroelectric Authority; by small sections within State Geological Surveys and the Bureau of Mineral Resources, which function as consultants to other government departments or private organizations; or by private consultants usually drawn from university staffs. The principal aim of engineering geology has been to improve engineering efficiency by forecasting difficulties in construction due to natural rock conditions and to decrease the time and cost of investigation. The growth in demand for, and status of, engineering geologists in the past ten years is proof that a degree of success has been attained. In general, the most

VULCANOLOGY

Studies of active vulcanism in Australia and New Guinea were violently inaugurated by the eruption at Rabaul in May, 1937. As a result of this, a vulcanological observatory was established at Rabaul and though seismographs and tiltmeters were installed, it was not fully equipped when the interruption of war occurred. It has been fully operative only for about the last ten years and instrumentation is still being improved. An even more spectacular occasion for vulcanological studies was the catastrophic Peleean eruption of Mt. Lamington in Papua in January, 1951, and, later, the unprecedentedly severe

13

eruptive period of Manam volcano, off the north coast of the mainland of New Guinea, from 1957 to the present. Other New Guinea volcanoes—Bam, Tuluman, Long Island, Langila, and Bagana—have been sporadically active also, and field studies have been carried out on these and other volcanoes. Plans are in hand for permanent observation posts equipped with seismographs, tiltmeters, and other instruments at Manam, where a temporary station has been maintained for three years, Mt. Lamington, and Esa-ala, in Eastern Papua. The establishment of a well-equipped seismological observatory at Port Moresby by the Bureau of Mineral Resources has been a big step forward in the study of the general seismicity of the area and the relations between regional seismicity and volcanic activity. A catalogue of the volcanoes of the southwestern Pacific—Volume V, Melanesia, of the Catalogue of Active Volcanoes of the World—was published in 1957. In Australia, considerable attention has been paid, especially since the' advent of aerial photography, to the manifestations of geologically recent vulcanism in western Victoria, southeastern and northern Queensland. Examination of the best preserved craters and lava flows in North Queensland suggests that the latest activity here must have occurred within historical times. Carbon 14 dating has given useful information about the ages of various ash deposits, some of them of major dimensions, at several of the New Guinea volcanoes, and palaeomagnetic studies will shortly be undertaken. ANTARCTIC GEOLOGY

Australian geological work in Antarctica has, to the present, consisted mainly of reconnaissance surveys. Landings on the coast were made by the British, Australian, and New Zealand Antarctic Research Expeditions in the early thirties, and this work has been continued since 1954 by the Australian National Antarctic Research Expeditions, so that rock exposures along almost the entire coast of the Australian territory have been visited, and airborne scintillometer surveys made of the larger rock outcrops.

The interior of the sector between 45° and 80° E., in which many thousands of square miles of rock are exposed, has been examined as far south as 75°. Work on the ground has of necessity been at scattered points, and interpolation, aided by aerial observations, has been used to produce a regional picture of the geology. Nevertheless, it is thought that the general distribution of the major rock types is now fairly well known. The two areas where knowledge is most lacking are the interior of the Enderby Land Peninsula and the head of the Lambert Glacier system. These deficiencies should be largely rectified by the end of the 1960-1961 field season. It will then be appropriate to begin systematic mapping of the several areas of concentrated rock exposures, and to make detailed studies of particular aspects—for example, the evolution and interrelations of the various rock types; physiographic features such as sea-level variations and the effects of glaciation; and on the structural side, block faulting and occurrence of dyke swarms. PUBLICATIONS

The most important publication issued during the post-World War II period is a three-volume work, Geology of Australia by T. W. E. David, edited by W. R. Browne. This contains a comprehensive bibliography of works on Australian geology up to 1946. Since then, the Geological Society publications on South Australia, Western Australia, and Queensland have included bibliographies of the geology of those states. Two books prepared by the Australasian Institute of Mining and Metallurgy for the Fifth Empire Mining Congress in 1953—Geology of Australian Ore Deposits and Coal in Australia—contain long lists of references to economic mineral deposits. Lexicons of Australian stratigraphy for each state have been compiled, mainly by the Bureau of Mineral Resources, under the auspices of the Sub-Commission of the International Stratigraphic Lexicon of the International Geological Congress, and these contain bibliographies of

14 all papers relevant to stratigraphy in the respective states. Following is a list of the principal avenues of publication of geological papers and reports in Australia. In addition, of course, a number of articles are published in overseas journals such as Economic Geology, Geological Magazine, etc.: COMMONWEALTH BUREAU OF MINERAL RESOURCES,

GEOLOGY

AND

GEOPHYSICS:

Bulletins, reports, summary reports on mineral resources, quarterly reviews of the mineral industry, maps and explanatory notes, and pamphlets. STATE DEPARTMENTS OF M I N E S :

QUEENSLAND: Annual reports, Queensland Government Mining Journal (monthly); geological survey publications. NEW SOUTH WALES: Annual reports, technical reports, memoirs (none since 1922), bulletins (none since 1925), mineral resources (none since 1 9 4 0 ) , Mineral Industry of New South Wales, I960. VICTORIA: Annual reports, boring records, Mining and Geological Journal; Geological Survey records (none since 1 9 3 7 ) , bulletins, memoirs. TASMANIA: Annual reports, Underground Water Supply papers; Geological Survey bulletins, Mineral Resources numbers. SOUTH AUSTRALIA:

A n n u a l report, M i n -

ing Review (twice annually); Geological Survey bulletins, reports of investigations (which include explanatory notes on published maps). WESTERN AUSTRALIA:

Annual

reports,

Mineral Resources numbers; Geological Survey bulletins and annual progress reports. ROYAL SOCIETIES:

(Mainly descriptive

papers dealing with the geology of small areas, published together with papers on other sciences). Queensland, proceedings; New South Wales, journal, monographs; Victoria, proceedings; Tasmania, papers, proceedings; South Australia, transactions, proceedings; Western Australia, journal. Linnean Society of New South Wales, proceedings. MUSEUMS: Queensland, memoirs; Australian, Sydney, records; National, Melbourne, memoirs; Queen Victoria, Tasmania, records; South Australia, records; Western Australia, records. UNIVERSITY DEPARTMENTS OF GEOLOGY:

Queensland, papers; Sydney, memoirs; Tasmania, symposia. OTHER

PUBLICATIONS:

Proceedings

of

the Australasian Institute of Mining and Metallurgy (papers on economic geology included with other mining and metallurgical subjects). Geological Society of Australia Journal (first issue 1954). Aerial, Geological and Geophysical Survey of Northern Australia, reports, Western Australia, Northern Territory, Queensland, and semi-annual ( 1 9 3 5 ^ i O ) . Australian Oil and Gas Journal (first issue 1954). Mining and Chemical Engineering Review, Tait Co., Melbourne (mostly reviews of mining company operations). Australian Journal of Science, Science House, Sydney (short contributions of current geological interest). State Electricity Commission, Victoria— geological reports. Joint Coal Board, Sydney, annual reports.

Geophysics in Australia 1 J . C. JAEGER 2 AND R . F. T H Y E R 3

Shaw instruments were established at the astronomical observatories in Perth and Melbourne in 1901, and in Adelaide and Sydney in 1906. Riverview, Australia's best known seismological station, began operating in 1909-

INTRODUCTION T H I S REVIEW IS RESTRICTED t o the g e o p h y s i c s

of the solid Earth and to the mainland of Australia, though occasional reference is made to associated regions. The Commonwealth Bureau of Mineral Resources, Geology and Geophysics is responsible for gravity and magnetic mapping of Australia and carries out extensive work on field and station seismology and other aspects of fundamental geophysics. This work has been extended to the Antarctic with the collaboration of the Antarctic Division of the Commonwealth Department of External Affairs. Geophysical prospecting carried out by other government agencies and by private companies provides further fundamental information for studies of the crust. In the universities, the Australian National University possesses a department of geophysics; the universities of Sydney, Melbourne, and Tasmania provide optional courses in geophysics in their geology departments; the physics departments of the universities of Western Australia, South Australia, and New South Wales, and the geology department of the University of Queensland, are all active in some branches of the subject. Magnetic observatories were established by Ross in Hobart in 1840 and by Neumayer in Melbourne over a century ago (Dooley 1958). Seismological stations equipped with Milne-

GRAVITY

During the last few years there has been a substantial increase in the number of gravity observations made in Australia. More than 10,000 new stations have been established during the past 12 months, about 70 per cent by private companies and the remainder by government agencies and universities. The Commonwealth Bureau of Mineral Resources, Geology and Geophysics is the national authority for collecting gravity data for regional and geodetic purposes. The private companies have generously made data available which have been used by the Bureau in preparing a Bouguer anomaly map of Australia. The datum for this work is the National Gravity Base Station ( N G B S ) at the Bureau's Geophysical Laboratory in Footscray, a suburb of Melbourne, Victoria. International connections with NGBS have been made by various overseas and Australian observers listed in Table 1. Groups of observations by individual authorities have been adjusted to datum through a network of 59 pendulum stations established by the Bureau during 1950 and 1951 with the Cambridge Pendulums (Dooley & others 1959). The estimated standard error of the Cambridge Pendulum measurements relative to NGBS is ± 0 . 6 mgal.

1 Reprinted from Geophysical Journal of the Royal Astronomical Society, vol. 3, no. 4, I960. 2 Australian National University, Canberra. 3 Bureau of Mineral Resources, Geology and Geophysics, Canberra.

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