Multi-element near-surface geochemistry from the National Geochemical Survey of Australia has been evaluated in the context of mapping the exposed to deeply buried major crustal blocks of the Australian continent. The major crustal blocks, derived from geophysical and geological data, reflect distinct tectonic domains comprised of igneous, metamorphic and sedimentary rock assemblages representing a time scale ranging from early Archean to recent Cenozoic. The geochemical data have been treated as compositional data to uniquely describe and characterize the geochemistry of the major crustal blocks across Australia according to the following workflow: imputation of missing/censored data, log-ratio transformation, multivariate statistical analysis, classification/allocation, and multivariate geospatial (minimum/maximum autocorrelation factor) analysis. Using cross validation techniques the uniqueness of each major crustal block has been quantified. The abilities to predict (1) the membership, or lack thereof, of a surface regolith sample to one, or none, of the major crustal blocks, and (2) the major crustal block at sites that have not been sampled are demonstrated. In conclusion, the surface regolith of the Australian continent contains a geochemical record of the original crustal block composition, despite secondary modifications due to physical transport and chemical weathering effects. <b>Citation:</b> E.C. Grunsky, P. de Caritat, U.A. Mueller, Using surface regolith geochemistry to map the major crustal blocks of the Australian continent, <i>Gondwana Research</i>, Volume 46, 2017, Pages 227-239, ISSN 1342-937X, https://doi.org/10.1016/j.gr.2017.02.011

This service provides access to inorganic geochemistry data obtained from chemical analyses of rock and regolith samples collected during mapping and sampling programs in Australia. This service will provide a spatial distribution of the sample attributes as well as provide a spatial distribution of the analytical composition of the samples with respect to major elements, minor elements and rare earth elements. This service includes original inorganic geochemistry data levelled to reference datasets.

Exploring for the Future (EFTF) is a four-year (2016-20) geoscience data and information acquisition program that aims to better understand on a regional scale the potential mineral, energy and groundwater resources concealed under cover in northern Australia and parts of South Australia. Hydrogeochemical surveys utilise groundwater as a passive sampling medium to reveal the chemistry of the underlying geology including hidden mineralisation. These surveys also potentially provide input into regional baseline groundwater datasets that can inform environmental monitoring and decision making. Geoscience Australia, as part of the Australian Government’s EFTF program, undertook an extensive groundwater sampling survey in collaboration with the Northern Territory Geological Survey and the Geological Survey of Queensland. During the 2017, 2018 and 2019 dry season, 224 groundwater samples (including field duplicate samples) were collected from 203 pastoral and water supply bores in the Tennant Creek-Mt Isa EFTF focus area of the Northern Territory and Queensland. An additional 38 groundwater samples collected during the 2013 dry season in the Lake Woods region from 35 bores are included in this release as they originate from within the focus area. The area was targeted to evaluate its mineral potential with respect to iron oxide copper-gold, sediment-hosted lead-zinc-silver and Cu-Co, and/or lithium-boron-potash mineral systems, among others. The 2017-2019 surveys were conducted across 21 weeks of fieldwork and sampled groundwater for a comprehensive suite of hydrogeochemical parameters, including isotopes, analysed over subsequent months. The present data release includes information and atlas maps of: 1) sampling sites; 2) physicochemical parameters (EC, pH, Eh, DO and T) of groundwater measured in the field; 3) field measurements of total alkalinity (HCO3-), dissolved sulfide (S2-), and ferrous iron (Fe2+); 4) major cation and anion results; 5) trace element concentrations; 6) isotopic results of water (δ18O and δ2H), DIC (δ13C), dissolved sulfate (δ34S and δ18O), dissolved strontium (87Sr/86Sr), and dissolved lead (204Pb, 206Pb, 207Pb, and 208Pb) isotopes; 7) dissolved hydrocarbon VFAs, BTEX, and methane concentrations, as well as methane isotopes (δ13C and δ2H); and 8) atlas of hydrogeochemical maps representing the spatial distribution of these parameters. Pending analyses include: CFCs and SF6; tritium; Cu isotopes; and noble gas concentrations (Ar, Kr, Xe, Ne, and 4He) and 3He/4He ratio. This data release (current as of July 2021) is the second in a series of staged releases and interpretations from the Northern Australia Hydrogeochemical Survey. It augments and revises the first data release, which it therefore supersedes. Relevant data, information and images are available through the GA website (https://pid.geoscience.gov.au/dataset/ga/133388) and GA’s EFTF portal (https://portal.ga.gov.au/).

This service provides access to inorganic geochemistry data obtained from chemical analyses of rock and regolith samples collected during mapping and sampling programs in Australia. This service will provide a spatial distribution of the sample attributes as well as provide a spatial distribution of the analytical composition of the samples with respect to major elements, minor elements and rare earth elements. This service includes original inorganic geochemistry data levelled to reference datasets.

This service provides access to hydrochemistry data (groundwater and surface water analyses) obtained from water samples collected from Australian water bores or field sites.

This service provides access to hydrochemistry data (groundwater and surface water analyses) obtained from water samples collected from Australian water bores or field sites.

This service provides access to hydrochemistry data (groundwater and surface water analyses) obtained from water samples collected from Australian water bores or field sites.