No abstract available

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.

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

The National Geochemical Survey of Australia (NGSA) has collected samples from 1315 sites located in 1187 catchments (~10% of which were sampled in duplicate) covering over 80% of Australia. At each site, two depth ranges were sampled and two grain size fractions were separated, giving 5260 samples to be analysed. Samples were analysed for: 1 - Total content of multiple elements in Geoscience Australia's laboratories using x-ray fluorescence (XRF) and inductively coupled plasma-mass spectrometry (ICP-MS)</li> 2 - total content of fluoride (F) in commercial laboratories using ion specific electrode (ISE) 3 - total content of platinum group elements (PGEs) in commercial laboratories using fire assay and ICP-MS 4 - aqua regia soluble content of selenium (Se) in a commercial laboratory using ICP-MS 5 - aqua regia soluble content of multiple elements, including low-level gold (Au), in a commercial laboratory using ICP-MS 6 - ligand-based extractable content of multiple elements in a commercial laboratory using ICP-MS. The detailed procedures for analysing the NGSA samples in various laboratories are described.

Plans for the National Geochemical Survey of Australia were presented to the geoscience agencies of all States and the Northern Territory in early 2007. The presentation entitled National Geochemical Survey of Australia: outline of a new proposal was given to: Primary Industries and Resources South Australia in Adelaide on 20 February 2007 Geological Survey of Western Australia in Perth on 21 February 2007 New South Wales Department of Primary Industries in Maitland on 29 March 2007 Geological Survey of Queensland in Brisbane on 2 May 2007 Northern Territory Geological Survey in Darwin on 3 May 2007 Minerals Resources Tasmania in Hobart on 16 May 2007 GeoScience Victoria in Melbourne on 17 May 2007

National Geochemical Survey of Australia field training for the geoscience agencies of all States and the Northern Territory took place during 2007 and early 2008. The knowledge transfer mechanisms comprise a detailed National Geochemical Survey of Australia: Field Manual (GA Record 2007/08), this training presentation and several days of in-field sample collection under the guidance of NGSA staff.

The National Geochemical Survey of Australia (NGSA) project was established under the Australian Government's Onshore Energy Security Program (2006-2011). The project is a collaboration between Geoscience Australia and the geological surveys of all States and the Northern Territory. The primary aim of the NGSA project is to provide pre-competitive data and knowledge to support exploration for energy resources in Australia. In particular, it will improve the existing knowledge of the concentrations and distributions of energy-related elements such as uranium (U) and thorium (Th) at the national scale. To date, the project has completed field sampling and sample preparation. Outlet sediments of 1186 large catchments covering >6 M km2 (or 80% of Australia) have been sampled at 2 depths. Sample analyses are under way and will include total, aqua regia digestion and non-selective partial extraction element contents. By June 2011, the NGSA project will deliver a web-based atlas of geochemical maps, a database and a series of reports describing the project and its results. For more information, please visit http://www.ga.gov.au/ngsa or contact Philip Main (philip.main@ga.gov.au)

Poster for the Australian Earth Sciences Convention 2010.

Map(s) of Be (beryllium) concentration (Total content, Aqua Regia soluble content, and/or Mobile Metal Ion soluble content) in Top Outlet Sediment (TOS) and/or Bottom Outlet Sediment (BOS) samples, dry-sieved to <2 mm and/or <75 um grain size fractions. Source: The Geochemical Atlas of Australia (Caritat and Cooper, 2011)

Map(s) of Cl (chlorine) concentration (Total content, Aqua Regia soluble content, and/or Mobile Metal Ion soluble content) in Top Outlet Sediment (TOS) and/or Bottom Outlet Sediment (BOS) samples, dry-sieved to <2 mm and/or <75 um grain size fractions. Source: The Geochemical Atlas of Australia (Caritat and Cooper, 2011)