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  • 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.

  • The 1:250 000 maps show the type and distribution of 51 regolith-landform units with unique dominant regolith-landform associations, and are a subset of the 205 mapping units on the six 1:100 000 maps. These units are distinct patterns of recurring landform elements with characteristic regolith associations. Geomorphic symbols indicate the location and type of geomorphic activity. The maps present a systematic analysis and interpretation of 1:89 000 scale 1973 RC9 aerial photography, 1:100 000 scale topographic maps (AUSLIG), and field mapping data. High resolution (250m line spacing) airborne gamma-ray spectrometry and magnetics (Geoterrex) were used where applicable

  • ABSTRACT: Building on method developments achieved during a series of precursor pilot projects, the National Geochemical Survey of Australia (NGSA) project targets catchment outlet (overbank) sediments as a uniform sampling medium. These transported, fine-grained materials are collected (from a shallow and a deeper level) near the lowest point of 1390 catchments, which cover 91% of the country. Dry and moist Munsell® colour, soil pH and electrical conductivity and pH of 1:5 (soil:water) slurries are recorded and laser particle size analysis and infrared spectroscopy are performed. The dried samples are sieved into two grain-size fractions (<2 mm and <75 mm) that are analysed by x-ray fluorescence (XRF) and inductively-coupled mass spectrometry (ICP-MS) (multi-element, total analyses), by ICP-MS after aqua regia digestion (multi-element, including low level gold), and specialised methods for platinum group elements, fluorine and selenium. At the time of writing, 78% of the samples have been collected and most analyses are completed for the first 25% of samples. The project is due for completion in June 2011.

  • 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. .../...

  • Arcview GIS containing a regolith-landfrom map with associated site database. Most sites have a field photograph hot linked into the GIS. Complementary datasets include, digital elevation model and enhanced Landsat TM imagery.

  • This map is designed to show broad regolith-landform units, giving a regional overview of the main regolith types and their associated landforms.Included are the author's detailed Explanatory Notes to the map.

  • Inland sulfidic soils have recently formed throughout wetlands of the Murray River floodplain associated with increased salinity and river regulation (Lamontagne et al., 2006). Sulfides have the potential to cause widespread environmental degradation both within sulfidic soils and down stream depending on the amount of carbonate available to neutralise acidity (Dent, 1986). Sulfate reduction is facilitated by organic carbon decomposition, however, little is known about the sources of sedimentary organic carbon and carbonate or the process of sulfide accumulation within inland sulfidic wetlands. This investigation uses stable isotopes from organic carbon (13C and 15N), inorganic sulfur (34S) and carbonate (13C and 18O) to elucidate the sources and cycling of sulfur and carbon within sulfidic soils of the Loveday Disposal Basin.

  • The 1:250 000 maps show the type and distribution of 51 regolith-landform units with unique dominant regolith-landform associations, and are a subset of the 205 mapping units on the six 1:100 000 maps. These units are distinct patterns of recurring landform elements with characteristic regolith associations. Geomorphic symbols indicate the location and type of geomorphic activity. The maps present a systematic analysis and interpretation of 1:89 000 scale 1973 RC9 aerial photography, 1:100 000 scale topographic maps (AUSLIG), and field mapping data. High resolution (250m line spacing) airborne gamma-ray spectrometry and magnetics (Geoterrex) were used where applicable