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  • A new continental-scale geochemical atlas and dataset for Australia were officially released into the public domain at the end of June 2011. The National Geochemical Survey of Australia (NGSA) project, which started in 2007 under the Australian Government's Onshore Energy Security Program at Geoscience Australia, aimed at filling a huge knowledge gap relating to the geochemical composition of surface and near-surface materials in Australia. Better understanding the concentration levels and spatial distributions of chemical elements in the regolith has profound implications for energy and mineral exploration, as well as for natural resource management. In this world first project, a uniform regolith medium was sampled at an ultra-low density over nearly the entire continent, and subsamples from two depths and two grain-size fractions were analysed using up to three different (total, strong and weak) chemical digestions. This procedure yielded an internally consistent and comprehensive geochemical dataset for 68 chemical elements (plus additional bulk properties). From its inception, the emphasis of the project has been on quality control and documentation of procedures and results, and this has resulted in eight reports (including an atlas containing over 500 geochemical maps) and a large geochemical dataset representing the significant deliverables of this ambitious and innovative project. The NGSA project was carried out in collaboration with the geoscience agencies from every State and the Northern Territory under National Geoscience Agreements. .../...

  • Joint Release of the National ASTER geoscience maps at IGC The ASTER (Advanced Spaceborne Thermal Emission and Reflectance Radiometer) Geoscience Maps are the first public, web-accessible, continent-scale product release from the ASTER Global Mapping data archive. The collaborative Australian ASTER Initiative represents a successful multi-agency endeavour, led by the Western Australian Centre of Excellence for 3D Mineral Mapping (C3DMM) at CSIRO, Geoscience Australia and the State and Territory government geological surveys of Australia, along with other national and international collaborators. National ASTER geoscience map These geoscience maps are released in GIS format as 1:1M map-sheet tiles, from 3,000 ASTER scenes of 60x60km. Each scene was cross-calibrated and validated using independent Hyperion satellite imagery. The new ASTER geoscience products range in their application from local to continental scales, and their uses include mapping of soils for agricultural and environmental management, such as estimating soil loss, dust management and water catchment modelling. They will also be useful for resource exploration, showing host rock, alteration and regolith mineralogy and providing new mineral information at high spatial resolution (30m pixel). This information is not currently available from other pre-competitive geoscience data.

  • Australia has a rich uranium endowment. Amongst other favourable geological conditions for the formation of uranium deposits, such as the presence of intracratonic sedimentary basins, Australia is host to widespread uranium-rich felsic igneous rocks spanning a wide range of geological time. Many known uranium deposits have an empirical spatial relationship with such rocks. While formation of some mineral systems is closely associated with the emplacement of uranium-rich felsic magmas (e.g., the super-giant Olympic Dam deposit), most other systems have resulted from subsequent low temperature processes occurring in spatial proximity to these rocks. Approximately 91% of Australia's initial in-ground resources of uranium occur in two main types of deposits: iron-oxide breccia complex deposits (~ 75%) and unconformity-related deposits (~ 16%). Other significant resources are associated with sandstone- (~ 5%) and calcrete-hosted (~ 1%) deposits. By comparison, uranium deposits associated with orthomagmatic and magmatic-hydrothermal uranium systems are rare. Given the paucity of modern exploration and the favourable geological conditions with Australia, there remains significant potential for undiscovered uranium deposits. This paper discusses mineral potential of magmatic- and basin-related uranium systems.

  • Data gathered in the field during the sample collection phase of the National Geochemical Survey of Australia (NGSA) has been used to compile the Preliminary Soil pH map of Australia. The map, which was completed in late 2009, offers a first-order estimate of where acid or alkaline soil conditions are likely to be expected. It provides fundamental datasets that can be used for mineral exploration and resource potential evaluation, environmental monitoring, landuse policy development, and geomedical studies into the health of humans, animals and plants.

  • Interpretation of the 2006 deep seismic reflection data across the western Lachlan Orogen of southeast Australia have provided important insights into crustal-scale fluid pathways and possible source rocks in the Victorian orogenic gold province. The seismic profiles span three of the most productive structural zones in Victoria: the Stawell, Bendigo and Melbourne zones. Variations in the age and style of gold deposits across the structural zones are reflected by changes in crustal structure and composition, as revealed by the seismic data.

  • Geoscience Australia (GA) has recently released regional airborne electromagnetic data (AEM) in two survey areas of the Pine Creek region. The Woolner Granite-Rum Jungle survey in the western part of the region was flown using TEMPESTTM and the Kombolgie survey in the eastern part was flown using VTEMTM. These data assist in mapping geological features deemed to be critical for fertile unconformity-related uranium and sandstone-hosted uranium systems. These mapped features in combination with other datasets are used to assess the prospectivity of uranium systems.

  • Improving techniques for mapping land surface composition at regional- to continental-scale is the next step in delivering the benefits of remote sensing technology to Australia. New methodologies and collaborative efforts have been made as part of a multi-agency project to facilitate uptake of these techniques. Calibration of ASTER data with HyMAP has been very promising, and following an program in Queensland, a mosaic has been made for the Gawler-Curnamona region in South Australia. These programs, undertaken by Geoscience Australia, CSIRO, and state and industry partners, aims to refine and standardise processing and to make them easily integrated with other datasets in a GIS.