This report deals with an investigation of the electrical resistivities of a variety of wet surface soils, gravels and sands. The work may be regarded as preliminary to an investigation by Mr. R.F. Thyer into the detection of electrically resistive bodies buried in wet soils at shallow depths. It was required to determine the range over which the resistivities of surface soils vary, and also the changes that may be expected in any one type of soil between measurements made within any 1 foot of each other. Measurements were made in four localities, three being in the bed or on the banks of the Molonglo River, where the surface materials are sand, gravel, silts, and in some places, clay. The fourth locality was near the head of Sullivan's Creek, where the soil is a heavy black clay.

Several quality control measures were taken during the project. These included: - Central provision of sampling equipment and sample bags to all field teams - Randomised sample identification scheme so that samples were presented to the laboratories in a sequence unrelated to the order in which they were collected (as much as practically feasible) - Prevention of contamination in the field and in the lab - Prevention of sample mix-up in the field and in the lab - Field duplicates: every 10th site, a field duplicate sample was collected to help quantify total (sampling + analytical) precision (not identified as such to the lab) - Certified Reference Materials (CRMs) TILL-1, TILL-2 (Natural Resources Canada) were run with every batch on GA's XRF & ICP-MS to help quantify analytical precision and bias - Laboratory duplicates (splits), internal project standards (MRIS, WRIS, ORIS, MRIS2, WRIS2), exchanged project standards (GEMAS-Ap, GEMAS-Gr from EuroGeoSurveys; SoNE-1 from United States Geological Survey), and international CRMs (TILL-1, TILL-3, LKSD-1, STSD-3 from Natural Resources Canada) were covertly inserted in the analytical suites for in-house and external analyses to help quantify analytical precision and bias (not identified as such to the lab) - Internal project standard (GRIS) for pH 1:5, EC 1:5 and grain size measurements (not identified as such to the lab) In addition to the above measures, the analytical labs applied their own QA/QC procedures, including running CRMs and/or internal standards, replicating digests and/or analysis, and analysis of blanks. The present report uses some of the above data to quantitatively assess the quality of the NGSA data, which allows a quality statement to be made about the NGSA data.

A new continental-scale geochemical atlas and dataset 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. .../...

Recently, continental-scale geochemical surveys of Europe and Australia were completed. Thanks to having exchanged internal project standards prior to analysing the samples, we can demonstrate direct comparability between these datasets for 10 major oxides (Al2O3, CaO, Fe2O3, K2O, MgO, MnO, Na2O, P2O5, SiO2 and TiO2), 16 total trace elements (As, Ba, Ce, Co, Cr, Ga, Nb, Ni, Pb, Rb, Sr, Th, V, Y, Zn and Zr), 14 aqua regia extracted elements (Ag, As, Bi, Cd, Ce, Co, Cs, Cu, Fe, La, Li, Mn, Mo and Pb), Loss On Ignition (LOI) and pH. By comparing these new datasets to one another, we can learn lessons about continental-scale controls on soil geochemistry and about critical requirements for global geochemical mapping. Although the median soil compositions of both continents are overall quite similar, the Australian median values are systematically lower, except for SiO2 and Zr. This reflects the generally longer and, locally more intense weathering in Australia (median Chemical Index of Alteration values are 72 and 60% for Australia and Europe, respectively). We found that element concentrations typically span 3 (and up to 5) orders of magnitude on each continent. The comparison of 2 continental geochemical surveys shows that the most critical requirement for global geochemical mapping is good analytical quality. Only where a comprehensive quality control program, including field and laboratory duplicates, internal project standards and Certified Reference Materials, is implemented and documented, are the results credible and comparable with other datasets.

Global-scale mapping of surface mineralogy is now becoming possible using remote hyperspectral sensing technologies. Global-scale mineral maps have now been generated for Mars using thermal infrared hyperspectral data collected from the Mars-orbiting Thermal Emission Spectrometer (TES- http://jmars.asu.edu/data/), including maps of feldspar, pyroxene, olivine and quartz contents. Other mineral maps of Mars are now being assembled using the recently launched Compact Reconnaissance Imaging Spectrometer (CRISM - http://crism.jhuapl.edu/), including sulphates, kaolinite, illite/muscovite, chlorites, carbonate and water (www.lpi.usra.edu/meetings/7thmars2007/pdf/3270.pdf). In contrast, even though mapping the mineralogy of the Earth's land surface can improve understanding and management of Earth's resources, including: - monitoring of soils (acid sulphate soils, salinity, soils loss and soil carbon); - better characterisation of regolith materials (e.g. transported versus in situ); - discovery of new mineral deposits using alteration vectors; and - more accurate environmental assessments during resource exploitation (baseline mapping, monitoring and closure)

The ability of thermal and shortwave infrared spectroscopy to characterise composition and textural was evaluated using both particle size separated soil samples and raw soils. Particle size analysis and separation into clay, silt and sand sized soil fractions was undertaken to examine possible relationships between quartz and clay mineral spectral signatures, and soil texture. Spectral indices, based on thermal infrared specular and volume scattering features, were found to discriminate clay mineral-rich soil from mostly coarser quartz-rich sandy soil, and to a lesser extent, from the silty quartz-rich soil. Further investigations were undertaken using spectra and information on 51 USDA and other soils within the ASTER Spectral Library to test the application of shortwave, mid- and thermal infrared spectral indices for the derivation of clay mineral, quartz and organic carbon content. A non linear correlation between quartz content and a TIR spectral index based on the 8.62 im was observed. Preliminary efforts at deriving a spectral index for the soil organic carbon content, based on 3.4 - 3.5 im fundamental H-C stretching vibration bands were also undertaken with limited results.

The present report is a compilation of 531 geochemical maps that result from the National Geochemical Survey of Australia. These constitute the first continental-scale series of geochemical maps based on internally consistent, state-of-the-art data pertaining to the same sampling medium collected, prepared and analysed in a uniform and well documented manner and over a short time period (four years). Interpretations of the data and maps will be published separately.

Soil mapping at the local- (paddock), to continental-scale, may be improved through remote hyperspectral imaging of surface mineralogy. This opportunity is demonstrated for the semiarid Tick Hill test site (20 km2) near Mount Isa in western Queensland. The study of this test site is part of a larger Queensland government initiative involving the public delivery of 25,000 km2 of processed airborne hyperspectral mineral maps at 4.5 m pixel resolution to the mineral exploration industry. Some of the mineral maps derived from hyperspectral imagery for the Tick Hill area include the abundances and/or physicochemistries (chemical composition and crystal disorder) of dioctahedral clays (kaolin, illite-muscovite and Al smectite, both montmorillonite and beidellite), ferric/ferrous minerals (hematite/goethite, Fe2+-bearing silicates/carbonates) and hydrated silica (opal) as well as soil water (bound and unbound) and green and dry (cellulose/lignin) vegetation. Validation of these hyperspectral mineral products is based on field soil sampling and laboratory analyses (spectral reflectance, X-ray diffraction, scanning electron microscope and electron backscatter). The mineral maps show more detailed information regarding the surface composition compared with the published soil and geology (1:100,000 scale) maps and airborne radiometric imagery (collected at 200 m line spacing). This mineral information can be used to improve the published soil mapping but also has the potential to provide quantitative information suitable for soil and water catchment modeling and monitoring.

Geoscience Australia and CO2CRC have constructed a greenhouse gas controlled release facility to simulate surface emissions of CO2 (and other greenhouse gases) from the soil into the atmosphere under controlled conditions. The facility is located at an experimental agricultural station maintained by CSIRO Plant Industry at Ginninderra, Canberra. The design of the facility is modelled on the ZERT controlled release facility in Montana. The facility is equipped with a 2.5 tonne liquid CO2 storage vessel, vaporiser and mass flow controller unit with a capacity for 6 individual metered CO2 gas streams (up to 600 kg/d capacity in total). Injection of CO2 into the soil is via a 120m long slotted HDPE pipe installed horizontally 2m underground. This is equipped with a packer system to partition the well into six CO2 injection chambers. The site is characterised by the presence of deep red and yellow podsolic soils with the subsoil containing mainly kaolinite and subdominant illite. Injection is above the water table. The choice of well orientation based upon the effects of various factors such as topography, wind direction, soil properties and ground water depth will be discussed. An above ground release experiment was conducted from July - October 2010 leading to the development of an atmospheric tomography technique for quantifying and locating CO2 emissions1. An overview of monitoring experiments conducted during the first subsurface release (January-March 2012), including application of the atmospheric tomography technique, soil flux surveys, microbiological surveys, and tracer studies, will be presented. Additional CO2 release experiments are planned for late 2012 and 2013. Poster presented at 11th Annual Conference on Carbon Capture Utilization & Sequestration, April 30 - May 3, 2012, Pittsburgh, Pennsylvania

The Atlas of Australian Soils (Northcote et al, 1960-68) was compiled by CSIRO in the 1960's to provide a consistent national description of Australia's soils. It comprises a series of ten maps and associated explanatory notes, compiled by K.H. Northcote and others. The maps are published at a scale of 1:2,000,000, but the original compilation was at scales from 1:250,000 to 1:500,000. Mapped units in the Atlas are soil landscapes, usually comprising a number of soil types. The explanatory notes include descriptions of soils landscapes and component soils. Soil classification for the Atlas is based on the Factual Key. This dataset has been modified to show only soil types. For more information go to http://www.asris.csiro.au/themes/Atlas.html