As a results of representations made to the Bureau of Mineral Resources by the Australian Aluminium Production Commission during 1948 a brief examination was made in July, 1949, of the area known as Sogeri Plateau which is situated some 24 miles east-north-east of Port Moresby. The object of the inspection was to determine whether any bauxitic laterite was present on the plateau and if so to obtain samples for chemical determination of alumina soluble in caustic soda solution, that is, alumina extractable by the Bayer process. Three car traverses of the area were made - one along the Sogeri-Uberi road, one along the Sogeri-Subitana road and one along the Sogeri-Eilogo road. Two grab samples were collected and sent for analysis. The findings of the examination of the area and the results of the chemical analyses are described in this report.

The use of airborne hyperspectral imagery for mapping soil surface mineralogy is examined for the semi-arid Tick Hill test site (20 km2) near Mount Isa in north-western Queensland. Mineral maps at 4.5 m pixel resolution include the abundances and physicochemistries (chemical composition and crystal disorder) of kaolin, illite-muscovite, and Al smectite (both montmorillonite and beidellite), as well as iron oxide, hydrated silica (opal), and soil/rock water (bound and unbound). Validation of these hyperspectral mineral maps involved field sampling (34 sites) and laboratory analyses (spectral reflectance and X-ray diffraction). The field spectral data were processed for their mineral information content the same way as the airborne HyMap data processing. The results showed significant spatial and statistical correlation. The mineral maps provide more detailed surface compositional information compared with the published soil and geology maps and other geoscience data (airborne radiometrics and digital elevation model). However, there is no apparent correlation between the published soil types (i.e. Ferrosols, Vertosols, and Tenosols) and the hyperspectral mineral maps (e.g. iron oxide-rich areas are not mapped as Ferrosols and smectite-rich areas are not mapped as Vertosols). This lack of correlation is interpreted to be related to the current lack of spatially comprehensive mineralogy for existing regional soil mapping. If correct, then this new, quantitative mineral mapping data has the potential to improve not just soil mapping but also soil and water catchment monitoring and modeling at local to regional scales. The challenges to achieving this outcome include gaining access to continental-scale hyperspectral data and models that link the surface mineralogy to subsurface soil characteristics/processes.

Soil is a common evidence type used in forensic and intelligence operations. Where soil composition databases are lacking or inadequate, we propose to use publicly available soil attribute rasters to reduce forensic search areas. Soil attribute rasters, which have recently become widely available at high spatial resolutions, typically three arc-seconds (~90 m), are predictive models of the distribution of soil properties (with confidence limits) derived from data mining the inter-relationships between these properties and several environmental covariates. Each soil attribute raster is searched for pixels that satisfy the compositional conditions of the evidentiary soil sample (target value ± confidence limits). We show through an example that the search area for an evidentiary soil sample can be reduced to <10% of the original investigation area. This Predictive Soil Provenancing (PSP) approach is a transparent, reproducible and objective method of efficiently and effectively reducing the likely provenance area of forensic soil samples. <b>Citation:</b> de Caritat, P., Simpson, T. and Woods, B. (2019), Predictive Soil Provenancing (PSP): An Innovative Forensic Soil Provenance Analysis Tool. <i>J Forensic Sci</i>, 64: 1359-1369. https://doi.org/10.1111/1556-4029.14060

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. .../...

Abstract The ability of thermal infrared (TIR) spectroscopy to characterise mineral and textural content was evaluated for soil samples collected in the semi-arid environment of north-western Queensland, Australia. Grain size analysis and separation of clay, silt and sand sized soil fractions were undertaken to establish the relationship between quartz and clay emissivity signatures and soil texture. Spectral band parameters, based on thermal infrared specular and volume scattering features, were found to discriminate fine clay mineral-rich soil from mostly coarser quartz-rich sandy soil, and to a lesser extent, from the silty quartz-rich soil. This study found that there was the potential for quantifying soil mineral and texture content using TIR spectroscopy. Key Words Soil composition, quartz, kaolinite, smectite, grain size, Tick Hill

The National Geochemical Survey of Australia (NGSA) provides the first national coverage of multi-element chemistry at a continental scale. The NGSA data is an important complement to other national-scale geological and geophysical datasets, particularly the Radiometric Map of Australia. The Radiometric Map of Australia shows potassium (K) measured directly from gamma-rays emitted when 40K decays to argon (40Ar), whereas thorium (Th) and uranium (U) do not emit gamma-rays. Instead, their abundances are inferred indirectly by measuring gamma-ray emissions associated with parent radionuclides (thallium-208 for Th, and bismuth-214 for U) within their radioactive decay chains. Airborne-derived grids provide a continuous prediction of these radioelements across the Australian landscape. In contrast, the NGSA data provide a series of precise single point geochemical measurements of surface (0-10 cm) and near-surface (~60-80 cm depth) unconsolidated catchment outlet sediments.

Spectral data from airborne and ground surveys enable mapping of the mineralogy and chemistry of soils in a semi-arid terrain of Northwest Queensland. The study site is a region of low relief, 20 km southeast of Duchess near Mount Isa. The airborne hyperspectral survey identified more than twenty surface components including vegetation, ferric oxide, ferrous iron, MgOH, and white mica. Field samples were analysed by spectrometer and X-ray diffraction to test surface units defined from the airborne data. The derived surface materials map is relevant to soil mapping and mineral exploration, and also provides insights into regolith development, sediment sources, and transport pathways, all key elements of landscape evolution.

Geoscience Australia and CO2CRC have constructed a greenhouse gas controlled release reference facility to simulate surface emissions of CO2 (and other GHG gases) from an underground slotted horizontal well into the atmosphere under controlled conditions. The facility is located in a paddock maintained by CSIRO Plant and Industry at Ginninderra, ACT. The design of the facility is modelled on the ZERT controlled release facility in Montana, which conducts experiments to develop capabilities and test techniques for detecting and monitoring CO2 leakage. The first phase of the installation is complete and has supported an above ground, point source, release experiment, utilising a liquid CO2 storage vessel (2.5 tonnes) with a vaporiser, mass flow controller unit with a capacity for 6 individual metered gas outlet streams, equipment shed and a gas cylinder cage. Phase 2 involved the installation of a shallow (2m depth) underground 120m horizontally drilled slotted well, in June 2011, intended to model a line source of CO2 leakage from a storage site. This presentation will detail the various activities involved in designing and installing the horizontal well, and designing a packer system to partition the well into six CO2 injection chambers. A trenchless drilling technique used for installing the slotted HDPE pipe into the bore hole will be described. The choice of well orientation based upon the effects of various factors such as topography, wind direction and ground water depth, will be discussed. It is envisaged that the facility will be ready for conducting sub-surface controlled release experiments during spring 2011.

The National Geochemical Survey of Australia (NGSA) project has collected catchment outlet sediment samples from 1315 sites located in 1186 catchments (~10% of which were sampled in duplicate) covering over 80% of Australia, in a collaborative venture between Geoscience Australia and the geoscience agencies of all States and the Northern Territory. At each site, composited samples were collected from two depth intervals: (1) the Top Outlet Sediment from 0-10 cm depth, and (2) the Bottom Outlet Sediment from 60-80 cm depth on average. In the laboratory, the samples were dried, homogenised and separated into two grain-size fractions: (1) a 'coarse' fraction (0-2 mm), and (2) a 'fine' fraction (0-75 um). All together, thus, 5260 samples were prepared for analysis. Bulk splits were also separated for the determination of bulk properties. Samples were analysed for up to 68 chemical elements after Total, Aqua Regia and Mobile Metal Ion digestion methods. Several quality control measures were taken throughout the project and the data quality was assessed in a separate report. This report used the acquired geochemical data to investigate the preliminary implications of this new national dataset on exploration for energy and mineral resources in Australia. This was mostly done by overlaying the NGSA data on coverages of known deposits and occurrences for selected commodities: uranium (U), thorium (Th), gold (Au), copper (Cu), lead (Pb), zinc (Zn) and Rare Earth Elements (REEs). For U, an attempt was made to distinguish between calcrete-related and intrusion-related deposit types, and a local case study in the Pine Creek area is also presented. For Zn, preliminary results from an investigation into discrete field modelling using concentration-area (CA) fractal plots are also presented. Coincidence of known mineral deposits and occurrences with elevated geochemical element concentrations in the same catchment are highlighted. Several catchments have elevated geochemical element concentrations in catchments with no known mineral deposits or occurrences, which provide potential targets for exploration. This technique constitutes a useful and rapid tool for area selection where further, more detailed exploration effort could be expended to test these geochemical anomalies.

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.