Abstract for initial submission, pending acceptance by convention technical program committee.

Tholeiitic intrusion-hosted nickel sulphide deposits are highly sort exploration targets due to their potential size and co-products platinum-group elements and copper. The Norilsk-Talnakh (Russia), Voisey's Bay (Canada) and Jinchuan (China) deposits are world class examples. Although Australia holds the largest economic resources of nickel in the world, its nickel resources are mainly sourced from komatiitic-hosted and lateritic deposits. Known resources of tholeiitic intrusion-hosted nickel sulphides are relatively small, with Nebo-Babel and Nova-Bollinger in Western Australia the most significant examples. Given the abundance of tholeiitic igneous rocks in Australia, this important deposit type seems to be under-represented when compared to other continents with similar geology. To support the discovery of world class nickel sulphide deposits in Australia, Geoscience Australia has recently undertaken a continental-scale GIS-based prospectivity analysis for tholeiitic intrusion-hosted deposits across Australia. This analysis exploits a suite of new relevant digital datasets recently released by Geoscience Australia. For example, the analysis utilises the Australian Mafic-Ultramafic Magmatic Events GIS Dataset which places mafic and ultramafic rocks across Australia into 74 coeval magmatic events based on geochronological data. Whole rock geochemistry of mafic and ultramafic rocks has been used to differentiate between magma series and discriminate between different magmatic events and units within those events. Other new datasets include crustal domain boundaries derived from both deep crustal seismic data and neodymium depleted mantle model age data as well as a coverage of the minimum thickness of mafic rocks in the crust derived from the Australian Seismogenic Reference Earth Model. This continental-scale GIS-based nickel sulphide prospectivity analysis uses a mineral systems approach to map the four essential components of ore-forming mineral systems; (1) sources of ore constituents, (2) crustal and mantle lithospheric architecture, (3) energy sources or drivers of the ore-forming system, and (4) gradients in ore depositional physico-chemical parameters. These four components are combined into a prospectivity map using weights-of-evidence GIS-based techniques, with the most prospective areas across the continent occurring where all components are present. The mineral systems approach allows for the identification of a much larger footprint than the deposit itself, and can be applied to greenfield and/or undercover areas. The results highlight areas that contain known tholeiitic intrusion-hosted nickel sulphide deposits, such as the Musgrave and Pilbara Provinces, as well as regions that do not contain any known deposits, such as the southern margin of the Arunta Province in the Northern Territory, the Mount Isa Province in Queensland and the Paterson Province in Western Australia.

The paper discusses the results from the GA-302 2D seismic survey and GA-2436 (RV Tangaroa) marine reconnaissance survey over the Capel and Faust basins, northern Tasman Sea. The integration of seismic, potential field and bathymetric data sets in 3D space at an early stage in the project workflow has assisted in the visualisation of the basin architecture, the interpolation of data between the seismic lines, and the iterative refinement of interpretations. The data sets confirm the presence of multiple depocentres, as previously interpreted from satellite gravity data, with a maximum sediment thickness of 5-7 km. Preliminary interpretation of the seismic data has identified two predominantly Cretaceous syn-rift and two Upper Cretaceous to Neogene sag megasequences overlying a heterogeneous pre-rift basement. The comparison of seismic facies and tectonostratigraphic history with offshore New Zealand and eastern Australian basins suggests the presence of possible Jurassic to Upper Cretaceous coaly and lacustrine source rocks in the pre- and syn-rift, and fluvio-deltaic to shallow marine reservoir rocks in the syn-rift to early post-rift successions. Preliminary 1D basin modelling suggests that the deeper depocentres of the Capel and Faust basins are within the oil and gas windows. Large potential stratigraphic and structural traps are also present.

Uranium-rich igneous rocks are recognised as an important source of metals in uranium mineral systems. Magmatic-related uranium mineralisation may be orthomagmatic in origin, forming via favourable igneous processes, or may result from the exsolution of uranium-rich fluids from particular magmas. Additionally, it is recognised that igneous rocks also may contribute directly to basin-related uranium mineral systems as a metal source. Thus, mapping of the distribution of uranium in igneous rocks has the potential to highlight prospective regions for uranium mineralisation at a macro-scale. Geoscience Australia has produced a series of three digital maps showing the uranium content of igneous rocks across Australia, drawing together geochemical and geological datasets from disparate open file sources. Map 1 shows the uranium concentration in whole rock geochemical analyses plotted as point data on a background of igneous rock type, which itself is derived from Geoscience Australia's 1:1 000 000 national surface geology map. Map 2 integrates these datasets, and shows the average uranium content of all intersecting geochemical data point for outcropping individual igneous rock units. In Map 3, a similar approach is employed in mapping the average uranium content of igneous rocks occurring under cover, using interpreted solid geology coverages. Combined, these maps provide a comprehensive picture of the province-scale trends in igneous uranium content across the continent. Using an applied knowledge of processes leading to uranium concentration in magmatic systems, igneous rocks exhibiting a favourable combination of factors are able to be identified for further analysis of prospectivity for uranium mineral systems.

Uranium deposits are generally classified into types based on host rock, orebody morphology or structural setting. Widely used schemes contain 14 or more deposit types and numerous sub-types. However, groups of deposit types were formed by similar geological and geochemical processes and likely represent 'variations on a theme'. An alternative scheme is presented that recognises the continuum of possible uranium deposit styles between three families of mineral systems: magmatic-related, 'metamorphic'-related, and basin-related. Formation of uranium deposits in each family involves fluids of three end-member type: magmatic-hydrothermal, 'metamorphic' (including diagenetic waters and fluids reacted with metamorphic rocks at elevated temperatures), and surface-derived fluids such as meteoric waters, seawater, lakewater and groundwater. By better understanding the fundamental geological and geochemical processes involved in ore formation in each family of uranium mineral systems, the most important geological 'symptoms' can be recognised and mapped. This mineral systems approach has been applied to magmatic-related uranium systems in Australia. The predictions of potential suggest that the under-representation of magmatic-related uranium resources relative to other parts of the world with similar geology may be due not to low endowment but to lack of discovery.

Under the Australian Government's Energy Security Program, Geoscience Australia conducted a seismic survey and a marine reconnaissance survey to acquire new geophysical data and obtain geological samples in frontier basins along the southwest Australian continental margin. Specific areas of interest include the Mentelle Basin, northern Perth Basin, Wallaby Plateau and southern Carnarvon Basin. The regional seismic survey acquired 7300 km of industry-standard 2D reflection seismic data using an 8 km solid streamer and 12 second record length, together with gravity and magnetic data. These new geophysical datasets, together with over 7000 km of re-processed open-file seismic data, will facilitate more detailed mapping of the regional geology, determination of total sediment thickness, interpretation of the nature and thickness of crust beneath the major depocentres, modelling of the tectonic evolution, and an assessment of the petroleum prospectivity of frontier basins along the southwest margin. The scientific aim of the marine reconnaissance survey was to collect swath bathymetry, potential field data, geological samples and biophysical data. Together with the new seismic data, samples recovered from frontier basins will assist in understanding the geological setting and petroleum prospectivity of these underexplored areas.

Review of 2009 Acreage Release

The generation of economic growth through mineral development activities can play an important role in supporting developing countries to achieve positive economic objectives. This report assesses the geoscience capability of 138 developing countries in four continent regions as identified by the Organisation for Economic Co-operation and Development (OECD). These countries are assessed using eleven sub-categories which can be grouped into four broad categories including: geological, geoscience survey capacity, socio-political risk, and geological aid. The comprehensive data compiled are largely presented graphically to facilitate ready comparisons between countries and continents. Recommendations for targeting and future structuring programs for maximum program impact are provided. The report utilises and synthesises both international information available to the public and commercial information obtained by Geoscience Australia. It has been prepared for the Australian Agency for International Development (AusAID: http://www.ausaid.gov.au/Pages/home.aspx). The report will be published online by AusAID and as a GA Record.

The map has two sheets. The first sheet shows resources of rare-earth elements by regions. The second sheet shows resources by deposit types.

Report on the activities of the administrative and technical sections in the Katherine-Darwin area, to October, 1954. A brief account is given of geological and geophysical operations. The results of prospecting and development work are summarised.