Catchment outlet sediments (0-10 cm depth, sieved to <2 mm) collected at a very low density over most of the Australian continent have been analysed using the Mobile Metal Ion (MMI®) partial extraction technique. Of the 54 elements analysed, eight are generally regarded as essential nutrients for plant growth: Ca, Cu, Fe, K, Mg, Mn, P and Zn. For these, 'bioavailability', defined here as the ratio of the partial digest concentration to the total concentration, has been investigated. This estimation of 'bioavailability' gives results comparable with standard agricultural measurements. Average 'bioavailability' ranges from 15.0% for Ca to 0.1% for Fe. Smoothed (kriged) colour contour maps for continental Australia have been produced for these eight nutrients and interpreted in terms of lithology (e.g., presence of carbonates in the MMI® Ca map), mineralization (e.g., well known and possibly less known mineral districts in the Cu, P and Zn maps), environmental processes (e.g., salinity in K map, weathering and acid generation in Fe map) and agricultural practices (e.g., application of fertilizers in P and Zn maps). This first application of a partial extraction technique at the scale of a continent has yielded meaningful, coherent and interpretable results.

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Predictive mineral discovery is concerned with the application of a whole of system process understanding to mineral exploration as opposed to an empirical deposit type approach. A mineral system process understanding can be derived from a consideration of five key questions, namely what is/are the: 1) geodynamic setting; 2) architecture; 3) sources and reservoirs; 4) drivers and pathways, and; 5) depositional mechanisms. The answers to these questions result in the identification of critical processes necessary for the function of a mineral system within a particular terrane, and permit the development of a targeting model. In this contribution we identify district scale critical orogenic gold mineral system processes for the late Archaean eastern Yilgarn Craton of Western Australia. During the geodynamic history of a terrane the critical processes which result in mineralisation change with time resulting in variations in mineralisation style. Proxies for critical processes have been mapped in an integrated GIS and are termed mappable mineral system process proxies (or MMSPP). In recognition of this, three separate time slices and a geochemical theme were analysed. Each MMSPP is given a weighting factor (WF) which reflects the spatial accuracy/coverage of the data and process criticality. For each theme/time-slice, a separate prospectivity map was created by summing the overlay or union of the spatial extent of each MMSPP, and adding the WF. A final target or prospectivity map was generated by a union of the four theme/time-slice prospectivity maps, and is tested against the known major deposits. The map 'discovered' the main gold camps and accounts for over 75% of the known gold in 5% of the area. This test verifies the process-based understanding and the appropriate mapping of the critical proxies. A further outcome from the map was the identification of a number of new target areas not known for significant gold mineralisation in what otherwise is thought to represent a mature terrane for gold exploration. The approach taken here has been to consider the Late Archaean gold deposits as a holistic system. Despite the recurring areas of uncertainty, this systems view has resulted in new findings that have generic applications to other mineral systems.

This glossary has been written to compile a single reference for terms commonly used in regolith science, to bring consistency and uniformity to the terminology of regolith science, and to explain the way words have been used in the regolith literature

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.

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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.

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. .../...

Rare-earth-element (REE) mineral systems in Australia are associated with igneous, sedimentary, and metamorphic rocks in a range of geological environments (http://www.ga.gov.au/image_cache/GA19657.pdf). Elevated concentrations of these elements have been documented in various carbonatite intrusions, (per)alkaline igneous rocks, iron-oxide breccia complexes, calc-silicate rocks (skarns), fluorapatite veins, pegmatites, phosphorites, fluvial sandstones, unconformity-related uranium deposits, lignites and heavy-mineral sand deposits (beach, dune, marine tidal, and channel). The distribution and concentration of REE in these deposits is influenced by various rock-forming processes including enrichment in magmatic or hydrothermal fluids, separation into mineral species and precipitation, and subsequent redistribution and concentration through weathering and other surface processes. The lanthanide series of REE and yttrium, show a close association with alkaline felsic igneous rocks, however, scandium in laterite profiles has an affinity with ultramafic-mafic igneous rocks.

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