This Bulletin describes the geology of the igneous and metamorphic rocks of the Lamboo Complex in the eastern part of the Kimberley Division of Western Australia (Fig. 1). The area encompasses the western halves of the Lissadell, Dixon Range, and Gordon Downs 1:250,000 Sheet areas, the eastern half of the Mount Ramsay Sheet area, and the southeastern corner of the Lansdowne Sheet area. It is bounded on the east by longitude 128°30'E and 129°E (on the Lissadell Sheet), on the west by longitude 127°30'E and 126°45'E (on the Mount Ramsay Sheet), and by latitude 16°00'S and 19°00'S. The mapping of the Lamboo Complex is part of a current investigation of the Kimberley Division by the Geological Survey of Western Australia and the Bureau of Mineral Resources.

This Bulletin presents the results of a marine geological survey carried out by BMR in the Arafura Sea in 1969 as part of a program of regional geological reconnaissance mapping of the Australian continental shelf. It is a continuation of work in the Timor Sea and northwest shelf (van Andel, Veevers, 1967; Jones, 1968, 1970). The area surveyed is the northern Australian continental shelf between longitudes 130° and 136°E and between latitudes 8° and 12°S (Fig. 1), an area of about 240 000 km-. From 2 to 25 May the Japanese research submersible Yomiuri and its mothership, the converted deepsea tug Yamato, were made available. The major part of the survey lasted from 21 September to 6 December 1969, using the chartered oil-rig supply vessel San Pedro Sound as a platform.

The Australian Calibration Line (ACL) , with a total gravity interval of 3 Gal, was established during 1970 between Laiagam in Papua New Guinea and Hobart in Tasmania. During 1973 the Australian Bureau of Mineral Resources and the USSR Geodesy and Cartography Survey made joint observations along the full length of the ACL. Measurements made with eight Soviet GAG-2 gravity meters established a gravity scale for Australia to an accuracy of 2.5 parts in 105. This scale and a datum of 979 671.86 mGal for Sydney A were adopted for Australia in 1973. The Soviet scale established for the ACL appears to be within 1 part in 104 of both the IGSN71 scale established for the Western Pacific Calibration Line by absolute determinations, pendulum measurements and international gravity meter comparisons, and the scale established for the Soviet Calibration Line by OVM pendulums. The Soviet scale for the ACL defines a milligal which is 1.5 parts in 104 larger than that defined by IGSN71 values for the ACL, and 5 parts in 104 larger than the 1965 Mean Australian Milligal that was used as an Australian milligal standard between 1965 and 1973. Both of these scales are partly based on Cambridge pendulum measurements made in Australia during 1950-51. These measurements are now thought to have been incorrect in scale. LaCoste, Romberg gravity meters have been used during six surveys along the whole or part of the ACL. The LaCoste observations have been reduced using the Soviet ACL scale and the new datum for Sydney A. The most probable values for airport gravity stations, calculated from the LaCoste results, have a precision of better than 0.01 mGal and are consistent to within experimental error with values calculated from the GAG-2 results. LaCoste observations reduced using the Soviet ACL scale give more accurate values for the gravity differences of the main intra-city ties and calibration ranges along the ACL.

The Solomon Sea is a semi-enclosed oceanic basin bordered by technically active land masses: its morphology is dominated by an arcuate trough, the New Britain Trench, which bounds the basin on its northern side and is over 8000 metres deep. Density of soundings is sufficient to reveal a large scale left-lateral displacement near the western end of the New Britain Trench; this appears to be a continuation of the onshore Markham-Ramu Lineament. The same structure controls the position of the Markham submarine canyon, which is the major conduit feeding sediment to the ocean basin. No continental shelf is developed along the northern margin of the Huon Gulf owing to the strong and continuing uplift of the Huon Peninsula, which lies within the Northern New Guinea Arc structural province. South of Lae, however, a narrow continental shelf is present. Seismic reflection profiles reveal that this shelf is a geologically young constructional feature, composed in its upper levels of a coalescing series of deltaic deposits. In some areas these can be seen resting directly on non-sedimentary basement. Several submarine canyons cross the shelf and each is closely related to a large river onshore. The seismic records clearly show truncation of strata by the canyon walls: however, it is postulated that upgrowth of the shelf around the canyons, with occasional slumping along the rims, as well as axial downcutting by abrasive sediment flowage, have controlled the formation of the canyons. Their steep axial gradients, which average about 5° compared with the shelf surface which slopes seaward at only 1°, are taken to indicate that the canyons were initiated before the Pleistocene and have maintained their courses during the upward and outward growth of the deltaic deposits forming the present day continental shelf.

The purposes of this Bulletin are to explain and describe the accompanying 1:10 000 000-scale geological map, to discuss briefly the map's units, and to provide readers and users with a guide to the rapidly expanding literature of Antarctic geology, from which they can obtain more detailed information.

The Proterozoic Mount Isa Inlier of northwestern Queensland is one of Australia's most important producers of copper, zinc, lead, and silver, accounting for over 40% of Australia's export earnings of these metals. Hence, it has been a focus of geological mapping and exploration for many years. BMR's interest began in the early 1950's, and by 1958 the entire inlier had been mapped at the broad reconnaissance level (1:250 000 scale) by joint BMR-GSQ (Geological Survey of Queensland) parties (Carter & others, 1961). This work established a stratigraphic framework for the inlier, and provided the first insight into its extremely complex structure. A more detailed (1:100 000 scale) second stage of mapping, again by joint BMRGSQ parties, began in 1969 and was largely completed by1980. This work extensively revised the stratigraphic picture, and the timing of major igneous events was determined using U-Pb geochronology. Blake (1987) synthesised the mapping results and prepared a 1:500 000 map of the entire inlier. The third BMR mapping stage began in 1983 and finished in 1989, and was concerned with detailed structural, penological (both igneous and metamorphic), sedimentological, and geochronological studies by BMR and BMR-supported university workers. The results of this work are presented as separate papers in this bulletin and as a set of individual geological maps at various scales on which most of the papers are based; the individual maps are synthesised into a 1:250 000 scale transect map which accompanies this bulletin. The maps are listed in the Table of Contents, and the locations of the mapped areas are shown in Figure 1. BMR is currently (1992) preparing a metallogenic analysis and Geographic Information System of the Mount Isa Inlier in ARC/INFO format (Wyborn & Gallagher, in preparation), which will incorporate the following digital datasets: the 1:500 000 scale geological map of Blake (1987); geochemical data; regional geophysical data; metallogenic data (Raymond & Fortowski, in press); and Landsat TM imagery.

Beyrichicopids and kirkbyocopes are represented in the Early Carboniferous benthic ostracod fauna of the Bonaparte Basin by at least 29 species referable to 18 genera (including two that are probably new, but unnamed). The described number of species are distributed among the ostracod families. Of the species described, eight are new (Libumella bonapartensis, Welleriella atypha, Malnina spinosa, Coryellina excaudata, C.robertsi, Selebratina serotina, Tetrarhabdus dictyon, and Scrobicula inaequalis), eight are closely related to, if not conspecific with, established taxa [Pseudoleperditia cf. venulosa, Coryellina cesarensis, Kirkbya aff. lessnikovae, K. aff. quadrata, Amphissites aff. centronotus, A. umbonatus, Kirkbyella (Berdanella) quadrata, and Scrobicula aff. inaequalis), and 13 are placed in open nomenclature, most of which are comparable with previously described taxa. The morphological similarities of the extinct Kirkbyacea and the extant Punciacea are discussed, and possible homoemorphic resemblances between them are considered. Detailed SEM examination of the reticulation pattern of the kirkbyacean species Amphissites sp.B revealed the results of epidermal cell-division during the ecdysis between the A-I stage and the presumed adult stage. Mitosis of the epidermal cells not only increases the valve surface area, but also initiates carinae by the fusion of adjacent muri of twin fossae. An interim biostratigraphic scheme for the Early Carboniferous sequence of the Bonaparte Basin consists of a succession of eight ostracod assemblages that are based on the first appearance (in ascending order) of the following species: Welleriella atypha, Coryellina robertsi, Shivaella cf. armstrongiana, Coryellina cesarensis,. Malnina spinosa sp. nov., Selebratina serotina, Scrobicula inaequalis and A mphissites sp.B. The scale of assemblages is controlled by conodont and foraminiferal zonations, and is calibrated against the Dinantian time-scale. So far, the atypha, robertsi and armstrongiana Assemblages have been recognised in the Early Carboniferous (Tournaisian) sequence of the Canning Basin. The major affinities of the Early Carboniferous beyrichicopids and kirkbyocopes from the Bonaparte Basin are with cognate species from Western Europe (Belgium, northern England), the Russian Platform, Kazakhstan, and Tibet. North American affinities are of minor significance. In general terms, the entire Early Carboniferous ostracod fauna from the carbonate shelf sediments of the Bonaparte Basin belongs to the Bairdiacea-Paraparchitacea ecozone, suggesting warm climatic conditions. The Tournaisian (Burt Range Formation; Septimus Limestone) faunas may include ecologically mixed assemblages, i.e., marine nearshore and shallow offshore, but the palaeoecological studies needed to test this model must await the description of the total Early Carboniferous ostracod fauna. The Visean (Utting Calcarenite) Kirkbyacea are as frequent (in species abundance) as the Paraparchitacea, both superfamilies ranking second to the Bairdiacea; a proportion indicative of open-marine shallow offshore conditions.

An overview of the Permian coals and coal bearing basins of eastern Australia is presented. The report is unusually large because it covers an enormous area equivalent to the Carboniferous coal basins of Europe from Scotland, through France, Germany and Poland, to the western Soviet Union. The report contains two major data-bases (see microfiches in vol. 1). The BMR data-base covers the stratigraphy and structure of the basins between the coast and the middle of the Great Artesian Basin, and between Cape York and Tasmania. The CSIRO data-base deals with the properties of the coals in these basins. The databases are summarised in 42 plates (vol. 2) and dozens of line drawings showing surface and under ground geology, stratigraphy, sedimentology and structure, and the chemical and petrographic properties of the coals. T h e illustrations are described and discussed in the text. Three tectonic groups of basins exist: (1) small rifts and valleys with seams u p to 30 m thick; (2)large interior intracratonic basins, with histories comparable to the North Sea and West Siberia Basins, e.g., the Cooper and Galilee Basins, which formed on an early Palaeozoic orogen, were filled by mainly non-marine sediments and coals (over 3 x 101 2 tonnes, but not yet mined), and were then covered by the Mesozoic Great Artesian Basin; and (3) marginal basins, so-called because they formed near the Permian coast of Australia. In the last group, the Sydney-Bowen Basin, which contains almost all of the major black coal mines, was 1700 km long, sub-parallel to the present east coast, and was separated from the palaeo-Pacific Ocean only by a ridge in the developing Palaeozoic and Mesozoic New England-Yarrol Orogen. The basin is thought to have been a foredeep to the orogen, and was possibly also a marginal basin formed over a strike-slip fault system at the western edge of the orogen. The interior and marginal basins have basal, middle, and upper coal measures, which are separated in the interior basins by lacustrine sediments and in the marginal basins by marine sediments. An ice sheet, reaching its maximum in the Early Permian, extended from Antarctica to the southern quarter of Australia. Periglacial conditions occurred farther north but moved southwards as the ice waned in the late Permian, being succeeded by cold-temperate conditions resulting in the widespread upper coal measures. In the marginal basins they were deposited in prograding sedimentary environments, ranging from alluvial fan through fluvial to deltaic, but were subject to marine incursions (one eustatic), and some deformation. They also received a large volume of volcanogenic sediments from major igneous centres in the orogen. With higher and more stable palaeo-water tables, and faster deposition, the marginal basins generally have coarsely banded coals, rich in vitrinite and with high semifusinite ratios. The interior basins had lower water tables and slower deposition and tend to have finely banded coals, low in vitrinite and with low semifusinite ratios. High sulphur, as usual, is related to marine influences. Coal rank is a matter that has received much attention, in part because of its significance in petroleum exploration. It can be correlated directly with palaeo-temperatures in the basins, and indirectly with depths of burial which, in turn, were controlled by Permian tectonic events, and by several Mesozoic and Cainozoic episodes of folding, faulting and igneous activity. Some of these events were more localised than others, but the rank changes are regular and systematic.

Between 1951 and 1959 four engineering geophysical surveys were made in the Great Lake North District of Tasmania. Gravity, magnetic, seismic, resistivity, and radiometric methods were used to investigate geological conditions and rock properties along the line proposed for tunnels and other works for a hydroelectric scheme. The surveys provided much information that was of value in both planning and construction of the scheme. This Bulletin incorporates the description of the four surveys and the results obtained by them. During the period of the geophysical surveys more diamond-drill holes were drilled by the Commission. In this Bulletin, the region surveyed will be referred to as the Great Lake North District and the separate parts as the Intake Tunnel Area, the Outlet Portal Area, the Penstock Line Area, and the Tailrace Tunnel Area.

Kimberley region is the name given to the rugged northern extremity of Western Australia, a large part of which is composed of Precambrian rocks. The area was mapped by combined teams of Bureau of Mineral Resources and Geological Survey of Western Australia geologists between 1962 and 1967: the results of the first three years' mapping of the southeastern part of the Kimberley region are given in this Bulletin. Isotopic age determinations were made on rocks throughout the Precambrian successions, and this has proved a valuable adjunct to the mapping.