At the request of the South Australian Government a gravity survey to investigate the possibility of further coal basins to the north of the Leigh Creek coalfield was commenced by officers of this Bureau in October, 1947. This survey was suspended in December, and a report was prepared dealing with the work carried out to that date (1948/004 and 1948/048). The area covered, however, was only a small part of a much larger area covered by a superficial layer of Tertiary rocks, beneath which a coal basin could exist. The work was resumed in May, 1948, and was continued until September, when the party was withdrawn. In additional to the geophysical field work carried out on the covered area to the north of the known coal deposits, some work was done on the Center or Telford basin. A number of traverses was read on the western edge of the basin, with a view to determining places where shallow coal might be found. The geology of the area, technical matters, results, and recommendations are discussed in this report. Accompanying plans are included.

This statement gives the results of a scout drilling campaign conducted by the Bureau at the Kirby's Hill Area of the Western Coalfield of New South Wales. The area investigated comprises approximately 200 acres of the parish of Cullen Bullen in the County of Roxburgh. At Kirby's Hill itself a maximum of about 300 feet of Coal Measure rocks rests on Upper Marine beds, and this is one of the most westerly exposures of the Upper Coal measures. The purpose of scout drilling was to determine the suitability of the Lithgow and Irondale Seams for open cut exploitation.

In Portion 11, Ph. of Stockrington Diamond Drilling near an unnamed creek tributary to Surveyor Creek has disclosed coal continuously for a distance of 7,600 feet south from the northern boundary of the Portion. The seam is split and banded and the coal is inherently high in ash. Proximate analyses of the coal were carried out by the New South Wales Mines Department laboratory in Sydney. All coal ores were forwarded from the field and shale etc. bands of greater thickness than half an inch were discarded by the analysts. Stony coal or carbonaceous shale with S.G. greater than 1.6 was also rejected from the assay samples. Consequently the analyses quoted indicate a composition roughly equivalent to that which might be expected for cleaned or hand-picked coal from this area.

As part of Geoscience Australia's Onshore Energy Security Program the authors have investigated whether there is any evidence that a sandstone hosted uranium system has operated in the Eromanga Basin and assessed the basin's potential to host significant uranium mineralisation.

This report deals with the results of 25,000 ft. of boring over an area of 15 sq. miles. Twenty-six coal seams were identified and named. Total reserves of all seams with band-free thickness greater than 4.0 ft. are 200,000,000 tons. Net open-cut reserves (to 9:1 ratio) of 7,500,000 tons over an area of 400 acres were tested and defined on four seams. All work in the Howick Area was done in the period March, 1952, to June, 1953.

Considerable exploration interest has been generated by the platinum-group-element (PGE) and Ni-Cu potential of the Archean layered mafic-ultramafic intrusions in the west Pilbara Craton, Western Australia. The Munni Munni Intrusion contains the largest known resource of PGEs associated with a layered intrusion in Australia, and the Radio Hill and Mount Sholl intrusions host significant resources of Ni-Cu-Co sulfides. Titaniferous magnetite layers, remobilized sulfides, and structurally controlled hydrothermal polymetallic deposits have also been a focus for exploration in recent years. The ca. 2.9 Ga Munni Munni, Andover, Radio Hill, Mount Sholl, and Sherlock layered intrusions are a cogenetic suite of high-level (<5 kb) bodies that represent some of the oldest mineralizing systems of their type in the world. Although they display similar field relationships and mineralogical, geochemical, and isotopic features, their contrasting chalcophile metal distribution patterns show that the timing and mechanism of the S-saturation event were critical for the development of PGE-enriched sulfide-bearing layers and basal segregations of base-metal sulfides. The intrusions form thick (>5.5 km) 'dike'-like bodies or relatively thin (0.5-2 km) sheets and sills emplaced at different levels along major lithological discontinuities in the upper crust. Rhythmically layered ultramafic components are generally thinner than, and occur along the northern sides of, more massive overlying mafic components. The ultramafic zones consist of dunite, lherzolite, wehrlite, olivine websterite, clinopyroxenite, and websterite. Inverted pigeonite gabbronorite, magnetite gabbro, olivine gabbro, anorthositic gabbro, and anorthosite comprise the mafic sequences. Olivine and clinopyroxene were generally the first minerals to crystallize, except in the Andover Intrusion, where orthopyroxene preceded clinopyroxene and possibly reflects greater contamination of the parent magma by felsic crustal material. The crystallization of chromite was inhibited in the ultramafic zones by the partitioning of Cr into early crystallizing clinopyroxene, thus downgrading the potential for PGE-chromite associations. The PGE mineralization in the Munni Munni Intrusion occurs in the upper levels of a porphyritic plagioclase websterite orthocumulate layer directly below the ultramafic-gabbroic zone contact. Mineral compositional trends and Nd isotopic data indicate that a Pd-Pt-Au-enriched S-undersaturated magnesian basaltic magma was frequently injected into a small magma chamber during formation of the ultramafic zone. A major influx of more fractionated, S-saturated tholeiitic gabbroic magma related to the resident magnesian magma, rapidly inflated the chamber and induced turbulent magma mixing that resulted in the formation of the PGE-bearing porphyritic websterite layer. In contrast, the parent magmas that formed the Mount Sholl, Radio Hill, Andover, and Maitland intrusions were saturated in S before they were emplaced into the magma chambers. In these intrusions gravitational and structural controls were important for the concentration of PGE-poor (5-400 ppb Pt + Pd + Au) massive sulfides in depressions and structural embayments along the basal contacts beneath the thickest sequences of mafic-ultramafic cumulates. The parent magmas to the west Pilbara intrusions were siliceous high-Mg basalts of Al-depleted komatiitic affinity (Barberton-type) with 9-12% MgO, 15-25 ppm Sc, 12-18 ppm Y, low Al2O3/TiO2 (ca. 11, or half chondrite ratios), and light-rare earth enrichment (chondrite-normalized La/Sm = 2.7, La/Lu = 9.0). They were generated with garnet in the residual asthenospheric mantle with probable involvement of a pre-3.0 Ga subduction-modified lithospheric mantle. Isotopic and geochemical modelling suggests that the magmas were contaminated by ca. 3.0-3.3 Ga Archean tonalitic to granodioritic crust before being emplaced into high-level magma chambers.

Precambrian layered mafic-ultramafic intrusions in Australia have recently generated considerable exploration interest for their platinum-group element (PGE: Pt, Pd, Rh, Ru, Os, Ir) and Ni-Cu-Co potential. Exploration has been stimulated by the discovery of potential world-class deposits (Voisey?s Bay, Canada; west Musgraves), high metal prices (notably Pd, Pt, and Rh), and a perception that many favourable intrusions are under-explored for different styles of orthomagmatic and hydrothermal mineralisation. Despite the renewed interest, Ni production associated with layered intrusions accounts for only 3% of Australia?s Ni production, and PGE production is currently restricted to the Archaean komatiitic-volcanic associations of the Yilgarn Craton. Exploration programs (see Hoatson & Blake 2000) for Precambrian layered intrusions vary considerably for different styles of precious- and base-metal mineralisation. The four styles of mineralisation considered here are believed to have the greatest potential in the following major orogenic domains: (1) Stratabound PGE-bearing sulphide layers: Yilgarn Craton, Pilbara Craton, Musgrave Block, Gawler Craton; (2) Stratabound PGE-bearing chromitite layers: Halls Creek Orogen, Albany?Fraser Orogen, Yilgarn Craton; (3) Basal segregations of Ni-Cu-Co?PGE sulphides: Musgrave Block, Pilbara Craton, Yilgarn Craton, Halls Creek Orogen, Arunta Block, Gawler Craton; and (4) Hydrothermal PGE remobilisation: Pilbara Craton, Arunta Block, Halls Creek Orogen, Yilgarn Craton, Musgrave Block, Gawler Craton. During the exploration of layered intrusions it is important not to be `blinkered? to a particular model, but to maintain a flexible innovative approach and consider different styles of orthomagmatic and hydrothermal mineralisation at different stratigraphic levels in the intrusion. It should also be borne in mind that it took more than 20 years of intensive exploration to define the J-M Reef of the Stillwater Complex, and it was not until the 1990s that a significant Au-PGE layer (Platinova Reef) was found in the Skaergaard Intrusion, East Greenland?an intrusion which has been investigated in great detail for more than 60 years.

National map which identifies Australia's major current and historic mines and yet-to-be-developed mineral deposits overlayed on the main mineralised geological regions and infrastructure themes (population centres, major road and rail networks, oil and gas fields and pipelines, oil refineries, export ports for mineral commodities, and major power generating sites).

Thematic map showing the distribution and age of Australia's diamond deposits and related rock types

Magmatic-related uranium resources are globally significant. Nevertheless, this class of uranium mineralisation is poorly represented among Australia's total known resources. This is despite the presence of numerous uranium-rich magmatic events distributed across a large part of the country, and across a vast span of geological time. To assess the potential for magmatic-related uranium mineral systems in Australia, three maps have been produced showing the uranium contents of Australian igneous rocks. Geological datasets incorporating both solid and surface geology, as well as geochemical data, have been compiled from a diverse range of open-file sources. This Record is intended to provide background information relating to these data sources and methodologies used in the production of the maps. The maps illustrate the large spatial extent of uranium-rich igneous rocks in Australia, with occurrences in all jurisdictions where uranium exploration is currently permitted. The maps also permit ready recognition of particularly enriched rocks on a pluton or wider scale. Identification of these areas has application to exploration for magmatic-related uranium systems, as well as certain basin-related uranium systems, where uranium-rich igneous rocks formed part of the metal source. Analysis of the compiled geochemical data reveal that high uranium content is most commonly associated with evidence of extensive fractional crystallisation. Fluorine contents, bulk rock composition, melt temperature, and temporal setting are also important. This preliminary interpretation demonstrates that an applied understanding of well-known igneous processes is able to account for the observed uranium content in uraniferous igneous rocks. Recommendations are given for future avenues of investigation into the prospectivity of Australian igneous rocks for magmatic-related uranium mineral systems, based on an understanding of the geochemical behaviour of uranium in igneous processes.