Top outlet sediments from the National Geochemical Survey of Australia (NGSA) have been extracted with Mobile Metal Ion (MMIR) solution and analyzed for over 50 elements including gold (Au). The MMIR Au results from this low density survey show discrete coherent anomalies for Au in the vicinity of many of Australia's known gold deposits, and in the vicinity of some minor gold occurrences. In several instances catchment outlet anomalies for Au have been recorded from areas not known to contain significant economic gold. Several large economic gold deposits are shown to not produce anomalies in catchment outlet samples. A survey of overbank samples in the Swan Avon Catchment of Western Australia at double the sampling density shows that low level anomalies (MMIR Au>1ppb) can be traced back to source using overbank sediments. Follow-up of one of the NGSA Au anomalies at Kent River in previously regarded non-auriferous terrain (western Albany-Fraser Belt) indicates a non-economic but perhaps geochemically significant Au anomaly with associated pathfinders including palladium. This may indicate that further exploration of the western part of Albany Fraser Belt for Au is warranted. The combination of catchment overbank samples and high-resolution MMIR technique has been shown to be effective at locating the source of gold anomalies from initial low-density continental and regional surveys.

The National Geochemical Survey of Australia (NGSA) was carried out to bridge a vast knowledge gap about the concentration and distribution of chemical elements at the Earth's surface and consequent poor understanding of processes controlling their distribution. The aim of the project was to contribute to derisking exploration for energy and mineral resources through the pre-competitive (government-funded) delivery of a new spatial layer of compositional data and information. Surface (0-10 cm depth) and shallow (~60-80 cm) samples of catchment outlet sediments were collected from 1315 sites located near the outlet of 1186 catchments (~10 % of which were sampled in duplicate) from across Australia. The total area covered by the survey was 6.174 million km2, or ~81% of Australia, at an average sampling density of 1 site per ~5200 km2. A number of field parameters (e.g., soil colour, pH), bulk parameters (e.g., electrical conductivity, particle size distribution) and geochemical parameters (i.e., multi-element composition of dry sieved <2 mm and <75 -m grain-size fractions) were determined. The grain-size fractions were analysed to determine (1) Total, (2) Aqua Regia soluble, and (3) Mobile Metal Ion (MMI®) extractable element contents. This data was collated into a spreadsheet and graphically represented as a series of 529 geochemical maps (www.ga.gov.au/ngsa). 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 thoroughly documented manner and over a short time period for Australia. They are being used to better understand the accumulation, mobility and significance of chemical elements in the near-surface environment. They provide a new, additional pre-competitive dataset for the energy and mineral resource exploration industry, which can help prioritise areas for further exploration investment and thus reduce risk. Further, some of this new information is already finding use in natural resource management and environmental monitoring. Applications to date and ongoing and future directions are discussed.

Lithium (Li) concentrations in catchment outlet sediment samples were measured as part of the National Geochemical Survey of Australia (NGSA; www.ga.gov.au/ngsa). Samples were collected at or near the outlet of 1186 catchments covering ~81% of Australia during 2007-2009. At each site a top outlet sediment (TOS) sample (0-10 cm depth) and a bottom outlet sediment (BOS) sample (~60-80 cm depth) were collected; each split into a 'coarse' (<2 mm) and a 'fine' (<75 mm) grain-size fraction. Li data is available for the Mobile Metal Ion (MMI®; TOS 'coarse' only) and Aqua Regia (AR) digestion techniques. Censored data (reported to be below the Lower Limit of Detection, LLD) account for 32% of the MMI® data (LLD = 0.005 mg/kg) and are absent from the AR dataset (LLD = 0.1 mg/kg); replacement values were imputed using a nearest neighbour method. The median MMI® value is three orders of magnitude lower than the median AR concentration. Further, there is an increase in median Li for the AR digestion following the order TOS 'coarse < BOS 'coarse' < TOS 'fine' < BOS 'fine'; in other words the deep or 'fine' samples have higher Li concentrations than their surface or 'coarse' counterparts. In order to assess the 'availability' of Li, the ratio of MMI® to AR Li (Li_Mi/Ai) was calculated and plotted. Li availability ranges from almost non-existent up to 14%. The map of Li_Mi/Ai shows that the regions of high Li availability correspond to the Yilgarn Craton, much of eastern South Australia, the southernmost, westernmost and central Northern Territory, south and western Queensland, western New South Wales and Victoria and a few coastal areas. These commonly are regions where salt lakes occur. However, assessment of Li content of source rocks and groundwaters and absence of active hydrogeological setting highlight limitations for the potential for Li-rich brines in Australian salt lakes.

Geochemical tracers have been used for many years to improve the understanding of reservoir dynamics in geothermal systems. Tracers can be classified as either conservative or reactive, and can be used in liquid-phase, vapour-phase or two-phase reservoirs at temperatures of 300C or more. They are commonly used to map flow pathways between injection and production wells in a geothermal field, to monitor the effects of reinjection and identify wells that might experience premature thermal breakthrough if left unmanaged. Tracer tests also provide information about reservoir fluid residence time, fluid recharge location or direction, swept pore volumes, inter-well connectivity, temperatures, fracture surface area, flow-storage capacity relationships and volumetric fluid sweep efficiencies. In addition, tracer data can be used with numerical transport codes to help validate 2D or 3D reservoir models. Thus, tracer tests can provide powerful insight into geothermal reservoir characteristics, and they can be performed at many stages of project development, from small-scale demonstration projects (e.g. an injection-production well doublet) through to large-scale commercial fields (e.g. Wairakei, New Zealand). New 'smart' tracers have the potential to be used with a single well to evaluate changes in fracture surface area following reservoir stimulation, and thus have applications to both conventional and unconventional (engineered) geothermal projects.

The International Geo-Sample Number (IGSN) provides a globally unique identifier for physical samples used to generate analytical data. This unique identifier provides the ability to link each physical sample to any analytical data undertaken on that sample, as well as to any publications derived from any data derived on the sample. IGSN is particularly important for geochemical and geochronological data, where numerous analytical techniques can be undertaken at multiple analytical facilities not only on the parent rock sample itself, but also on derived sample splits and mineral separates. Australia now has three agencies implementing IGSN: Geoscience Australia, CSIRO and Curtin University. All three have now combined into a single project, funded by the Australian Research Data Services program, to better coordinate the implementation of IGSN in Australia, in particular how these agencies allocate IGSN identifiers. The project will register samples from pilot applications in each agency including the CSIRO National Collection of Mineral Spectra database, the Geoscience Australia sample collection, and the Digital Mineral Library of the John De Laeter Centre for Isotope Research at Curtin University. These local agency catalogues will then be aggregated into an Australian portal, which will ultimately be expanded for all geoscience specimens. The development of this portal will also involve developing a common core metadata schema for the description of Australian geoscience specimens, as well as formulating agreed governance models for registering Australian samples. These developments aim to enable a common approach across Australian academic, research organisations and government agencies for the unique identification of geoscience specimens and any analytical data and/or publications derived from them. The emerging pattern of governance and technical collaboration established in Australia may also serve as a blueprint for similar collaborations internationally.

A major purpose of the study, as it appears to me at this time, is to ascertain the presence of geochemical anomalies in the area of (copper) mineralization. Such anomalies, if established, may be correlated with the dispersion train phenomena and with the dispersion halo of the ore, in an area known as mineralization. A comparable study may be undertaken then, depending on the advice of the team, in an area of suspected but not known, mineralization. Further investigations, beyond the reconnaissance stage, may be projected, in consultation with the team, on completion of the orientation study. This report contains the author's tentative remarks on a proposed reconnaissance in South Australia. Objectives, background to the work, methods, and proposed operations are discussed.

This was the first study of its kind, by the Commonwealth team. The study included demonstrations of the dithizone tests for traces of some heavy metals in the field environment, of operational and sampling procedures, and geochemical reconnaissance. Several reconnaissance traverses were sampled and examined. Extractable forms of copper and, in a very presumptive manner, extractable forms of lead and zinc were sought in the test materials. In addition, tests for copper, lead and zinc were made in some ignited and fused specimens. The testing procedure and results are described in this report.

One gram of sample No. 1 and 2 grams of No. 2 were dissolved in about 100mL of hot water. After dissolving the soluble portions the solutions were filtered and the undissolved portions dissolved and weighed. This weight subtracted from the original weight of the sample gave the amount of soluble salts. The filtrate was diluted to 250 mls with distilled water, 100 mls being used for Ca and Mg determination. The results of this experiment are given in the report.

The Milcarpa 1 borehole was drilled approximately 9 km SSE of Hungerford, Queensland, adjacent to the road between Hungerford and Wanaaring, NSW. The borehole was designed to test aeromagnetic anomalies in the basement rocks, test the electrical conductivity properties of cover and basement rocks to validate airborne electromagnetic (AEM) data, and to test pre-drilling geophysical cover thickness estimates.

The Tongo 1 borehole was drilled approximately 83 km NE of White Cliffs, New South Wales. The borehole was designed to test aeromagnetic anomalies in the basement rocks and to test the electrical conductivity properties of cover and basement rocks to validate airborne electromagnetic (AEM) data.