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.

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.

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.

Review of 2009 Acreage Release

Crustal magnetism is predominantly caused by the abundantly distributed ferrimagnetic mineral magnetite which posses the property of spontaneous magnetisation. Such magnetisation is dependent on temperature, which if high enough, will cause magnetite minerals to lose their magnetic property of spontaneous magnetisation and become paramagnetic. This temperature, known as the Curie point isotherm, occurs at ~580oC for magnetite. As temperature increases with depth in the crust, the Curie point can be taken as the depth at which the crustal magnetism ceases to be recorded. Using power spectral analysis of aeromagnetic data, we have generated a Curie point depth map for the Olympic Dam region in South Australia, host to the world's largest iron oxide-copper-gold-uranium deposit. The map shows an approximately 55 km long by 35 km wide and 40 km deep hemispherical depression in the Curie point depth beneath Olympic Dam, from a background average of around 20 km. Olympic Dam is notable for its large iron and uranium content, and it is located in a region of unusually high heat flow (av. 73 mWm-2). With such high heat flow one would expect the Curie point depth to be shallow. The paradox at Olympic Dam is that the Curie point depth is deep, raising questions about the geothermal gradient, depth-integrated abundance of heat-producing elements, and the source of the iron. A possible solution to the paradox is to interpret the deep Curie point depth as a giant hydrothermal alteration zone, where the heat-producing elements have been scavenged and concentrated into the upper crust, along with the gold and copper. The iron must have a significant mantle source as it is measured throughout the full crustal column. As iron is electrically conductive, such an interpretation is supported by the high conductivity measured deep beneath Olympic Dam.

This report deals with the results of 22,355 ft. of scout boring over an area of approximately 50 square miles on the western flank of the Muswellbrook (N.S.W.) Anticline. A traverse of overlapping bore-holes, located between the outcrops of the Upper Marine Series (Mulbring Beds) in the east and of the Triassic sediments in the west; provided a more complete section of the Upper Coal Measures in this area than has been previously available. Some 46 coal seams were encountered and tentatively numbered for correlation. Some of the coal seams exhibit very good qualities, but none could be classed as a good gas or coking coal. Igneous intrusions are numerous and of a fairly wide vertical and areal extent; their influence on the associated coal seams is generally destructive. The results of the above boring may be regarded as a basis, for any detailed future underground and/or open-cut mining investigations. No attempt was made to estimate coal reserves of any kind.

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.

Oil and gas discoveries in Australia's offshore basins are concentrated on the North West Shelf (Northern Carnarvon, Browse and Bonaparte basins) and Bass Strait (Gippsland, Otway and Bass basins). While discoveries have been made in a few regions outside these areas (e.g. Perth Basin), a large proportion of Australia's offshore basins remain exploration frontiers. However, the decline in oil production from the North West Shelf and Bass Strait basins since 2000 has led to an increasing exploration interest in the frontier basins. In order to improve our knowledge of the offshore frontiers and encourage exploration to these areas, from 2003-2011, Geoscience Australia was funded by the Australian Government to undertake a series of pre-competitive data acquisition and analyses programs in frontier basins around the Australian margin. This Record presents a comprehensive inventory of the geology, petroleum systems, exploration status and data coverage for 35 frontier basins, sub-basins and provinces, that draws on the results of those pre-competitive data programs, as well as exploration results and the geoscience literature. The Record also provides an assessment of the critical science and exploration questions and issues for each area. The results of each basin assessment are summarised in a prospectivity ranking. The availability of data and level of knowledge in each area is reflected in a confidence rating for that ranking. While the prospectivity of some areas is widely acknowledged to be high (e.g. Ceduna Sub-basin), the perception of prospectivity in many basins is negatively affected by the amount or quality of data available; in these basins, the acquisition of new data or targeted research could make a significant difference to the understanding of petroleum potential and likelihood of success. Therefore, recommendations for future work that could assist in addressing key knowledge or data gaps are included in each basin assessment.

This dataset represents the results of the assessment of the potential for uranium and geothermal energy systems in the southern Northern Territory. Four uranium systems were targeted: 1) sandstone-hosted, 2) uranium-rich iron oxide-copper-gold, 3) unconformity-related, and 4) magmatic-related. These were assessed for using a 2D, GIS-based approach, and utilised a mineral systems framework. In addition to the uranium systems investigated, the potential for hot rock and hot sedimentary aquifer geothermal systems was also assessed. Only the results of the hot rock geothermal assessment are presented here, since the assessment for hot sedimentary aquifer geothermal systems is more qualitative in nature. The assessment for hot rock geothermal systems was undertaken in a 3D environment, with temperatures at depth predicted using the 3D GeoModeller software package.

Assessing the regional prospectivity of tight, shale and deep coal gas resources in the Cooper Basin is an integral component of the Australian Government’s Geological and Bioregional Assessment Program, which aims to encourage exploration and understand the potential impacts of resource development on water and the environment. The Permo-Triassic Cooper Basin is Australia’s premier onshore conventional hydrocarbon-producing province, yet is relatively underexplored for unconventional gas resources. A chance of success mapping workflow, using rapid integration of new and existing data, was developed to evaluate the regional distribution of key gas plays within the Gidgealpa Group. For each play type, key physical properties (e.g. lithology, formation depths and extents, source rock and reservoir characteristics, and rock mechanics) were identified and criteria were used to assign prospectivity rankings. Parameter maps for individual physical properties were classified, weighted and then combined into prospectivity confidence maps that represent each play’s relative chance of success. These combined maps show a high chance of success for tight, shale and deep coal gas plays in the Nappamerri, Patchawarra and Windorah troughs, largely consistent with exploration results to-date. The outputs of this regional screening process help identify additional areas warranting investigation, and may encourage further exploration investment in the basin. This methodology can be applied to other unconventional hydrocarbon plays in frontier and proven basins.