Geoscience Australia and its predecessors have analysed hydrochemistry of water sampled from boreholes (both pore water and groundwater), surface features, and rainwater. Sampling was undertaken during drilling or monitoring projects, and this dataset represents a significant subset of stored analyses. Water chemistry including isotopic data is essential to better understand groundwater origins, ages and dynamics, processes such as recharge and inter-aquifer connectivity and for informing conceptual and numerical groundwater models. This GA dataset underpins a nationally consistent data delivery tool and web-based mapping to visualise, analyse and download groundwater chemistry and environmental isotope data. This dataset is a spatially-enabled groundwater hydrochemistry database based on hydrochemistry data from projects completed in Geoscience Australia. The database includes information on physical-chemical parameters (EC, pH, redox potential, dissolved oxygen), major and minor ions, trace elements, nutrients, pesticides, isotopes and organic chemicals. Basic calculations for piper plots colours are derived from Peeters, 2013 - A Background Color Scheme for Piper Plots to Spatially Visualize Hydrochemical Patterns - Groundwater, Volume 52(1) <https://doi.org/10.1111/gwat.12118>. Upon loading the data to the database, all hydrochemistry data are assessed for reliability using Quality Assurance/Quality Control procedures and all datasets were standardised. This data is made accessible with open geospatial consortium (OGC) web services and is discoverable via the Geoscience Australia Portal (<a href="https://portal.ga.gov.au/">https://portal.ga.gov.au/</a>). This dataset is published with the permission of the CEO, Geoscience Australia.

Hydrochemistry data for Australian groundwater, including field and laboratory measurements of chemical parameters (electrical conductivity (EC), potential of hydrogen (pH), redox potential, and dissolved oxygen), major and minor ions, trace elements, nutrients, pesticides, isotopes and organic chemicals. < <b>Value: </b>The chemical properties of groundwater are key parameters to understand groundwater systems and their functions. Groundwater chemistry information includes the ionic and isotopic composition of the water, representing the gases and solids that are dissolved in it. Hydrochemistry data is used to understand the source, flow, and interactions of groundwater samples with surface water and geological units, providing insight into aquifer characteristics. Hydrochemistry information is key to determining the quality of groundwater resources for societal, agricultural, industrial and environmental applications. Insights from hydrochemical analyses can be used to assess a groundwater resource, the impact of land use changes, irrigation and groundwater extraction on regional groundwater quality and quantity, assess prospective mineral exploration targets, and determine how groundwater interacts with surface water in streams and lakes. <b>Scope: </b>The database was inaugurated in 2016 with hydrochemical data collected over the Australian landmass by Geoscience Australia and its predecessors, and has expanded with regional and national data. It has been in the custodianship of the hydrochemists in Geoscience Australia's Minerals, Energy and Groundwater Division and its predecessors. Explore the <b>Geoscience Australia portal - https://portal.ga.gov.au/</b>

<div>This report details results and methodology from two hydrochemistry sampling programs performed as part of Geoscience Australia’s Musgrave Palaeovalley Project. The Musgrave Palaeovalley Project is a data acquisition and scientific investigation program based around the central west of Australia. It is aimed at investigating groundwater processes and resources within the Cenozoic fill and palaeovalleys of the region. This project, and many others, have been performed as part of the Exploring for the Future (EFTF) program, an eight-year, $225 million Australian Government funded geoscience data and precompetitive information acquisition program.</div><div>Data released here is from 18 bores sampled for groundwater and tested for a range of analytes including field parameters, major and minor elements, isotopes and trace gases. The sampling methods, quality assurance/quality control procedures, analytical methods and results are included in this report.</div>

<div>The Petroleum Systems Summary database stores the compilation of the current understanding of petroleum systems information by basin across Australia. The Petroleum Systems Summary database and delivery tool provide high-level information of the current understanding of key petroleum systems for areas of interest. For example, geological studies in the Exploring for the Future (EFTF) program have included the Canning, McArthur and South Nicholson basins (Carr et al., 2016; Hashimoto et al., 2018). The database and tool aim to assist geological studies by summarising and interpreting key datasets related to conventional and unconventional hydrocarbon exploration. Each petroleum systems summary includes a synopsis of the basin and key figures detailing the basin outline, major structural components, data availability, petroleum systems events chart and stratigraphy, and a précis of the key elements of source, reservoir and seal. Standardisation of petroleum systems nomenclature establishes a framework for each basin after Bradshaw (1993) and Bradshaw et al. (1994), with the source-reservoir naming conventions adopted from Magoon and Dow (1994).&nbsp;</div><div><br></div><div>The resource is accessible via the Geoscience Australia Portal&nbsp;(https://portal.ga.gov.au/) via the Petroleum Systems Summary Tool (Edwards et al., 2020).</div>

<div>The fluid inclusion stratigraphy database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases for Fluid Inclusion Stratigraphy (FIS) analyses performed by FIT, a Schlumberger Company (and predecessors), on fluid inclusions in rock samples taken from boreholes. Data includes the borehole location, sample depth, stratigraphy, analytical methods and other relevant metadata, as well as the mass spectrometry results presented as atomic mass units (amu) from 2 to 180 in parts per million (ppm) electron volts.</div><div> Fluid inclusions (FI) are microscopic samples of fluids trapped within minerals in the rock matrix and cementation phases. Hence, these FIS data record the bulk volatile chemistry of the fluid inclusions (i.e., water, gas, and/or oil) present in the rock sample and determine the relative abundance of the trapped compounds (e.g., in amu order, hydrogen, helium, methane, ethane, carbon dioxide, higher molecular weight aliphatic and aromatic hydrocarbons, and heterocyclic compounds containing nitrogen, oxygen or sulfur). The FI composition can be used to identify the presence of organic- (i.e., biogenic or thermogenic) and inorganic-sourced gases. These data provide information about fluid preservation, migration pathways and are used to evaluate the potential for hydrocarbon (i.e. dry gas, wet gas, oil) and non-hydrocarbon (e.g., hydrogen, helium) resources in a basin. These data are collated from Geoscience Australia records, destructive analysis reports (DARs) and well completion reports (WCRs), with the results being delivered in the Fluid Inclusion Stratigraphy (FIS) web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</div>

<div>A groundwater chemistry, regolith chemistry and metadata record for legacy geochemical studies over the southern Curnamona Province done by GA and partners as part of CRC LEME from 1999 to 2005, that was never fully released. This includes comprehensive groundwater chemistry from more than 250 bores in the Broken Hill region, containing physicochemical parameters, major and trace elements, and a suite of isotopes (34S, Pb, Sr, 18O, D). Recent work on this dataset (in 2021) has added hydrostratigraphic information for these groundwater samples. Also included is a regolith geochemistry dataset collected adjacent to some of the groundwater bores which tests the geochemical response of a range of different size fractions, depths and digests.</div>

<div>The Curnamona Province and overlying basins (herein referred to as the Broken Hill region) contain many discrete groundwater systems. These include sedimentary aquifers of the Lake Eyre Basin, Eromanga Basin, Darling Basin and Arrowie Basin, as well as fractured rock aquifers of the Adelaide Superbasin and Curnamona Province. However, there is little known about the hydrogeology or hydrogeochemistry of these aquifers in the Broken Hill region. Given the semi-arid climate in this region, understanding these groundwater systems can better support sustainable use of the groundwater for agriculture, mining and potable water supplies.</div><div>&nbsp;</div><div>Aquifer attribution provides a fundamental starting point for any hydrogeological study. We will present recently released hydrogeochemical data for the Broken Hill region, and our subsequent process for assessing and attributing hydrostratigraphy to the samples. </div><div>The Broken Hill Groundwater Geochemistry dataset (BHGG) was recently released in its entirety (Caritat et al. 2022 http://dx.doi.org/10.11636/Record.2022.020). It contains a compilation of archival CRC LEME hydrochemistry data that was collected as part of several projects from 1999 to 2005. This high-quality dataset contains 275 groundwater samples and includes a comprehensive suite of majors, minors, trace elements and stable isotopes (δ34S, δ18O, δ2H, δ13C, 87Sr/86Sr, 208/207/206Pb/204Pb). </div><div> At the time of collection, some key bore metadata (e.g. bore depths, screen and aquifer information) were missing from the original data compilations and these metadata are crucial for any hydrogeological analysis and interpretation. Therefore, as part of the new BHGG data release we have developed a robust and consistent approach to add bore information and aquifer attribution, value-adding to the original BHGG chemical and isotopic data. This workflow utilises a combination of State databases, reports, field notes, drillhole compilations and geological maps, but still relied on local hydrological expertise to make decisions when encountering incomplete or conflicting information (which is reflected by a confidence rating on the attribution). </div><div> The resulting BHGG product has supported re-assessment of the key hydrogeological and geochemical knowledge gaps in each groundwater system. An overview of knowledge gaps and the new sampling program being undertaken will be included in the presentation. &nbsp;</div><div><br></div>This Abstract was submitted/presented to the 2022 Australasian Groundwater Conference 21-23 November (https://agc2022.com.au/)

A comprehensive compilation of rock, regolith and groundwater geochemistry across the Curnamona Province and overlying basins. This product is part of the Curnamona Geochemistry module of GA's Exploring for the Future program, which is seeking to understand geochemical baselines within the Curnamona Province to support mineral exploration under cover. Data is sourced from GA, CSIRO and state databases, and run through a quality control process to address common database issues (such as unit errors). The data has been separated by sample type and migrated into a standard data structure to make the data internally consistent. A central source for cleaned geochemical data in the same data format is a valuable resource for further research and exploration in the region.

As part of Geoscience Australia's Exploring for the Future program, the East Tennant region, which is centred on the Barkly Roadhouse in the Northern Territory, was identified as having favourable geological and geophysical indicators of mineral systems potential. Potentially prospective stratigraphy in the East Tennant region is completely concealed beneath Mesoproterozoic to Quaternary cover sequences. Prior to 2020 basement rocks in the East Tennant region were only known from a handful of legacy boreholes, supported by geophysical interpretation. In order to test geophysical interpretations and obtain additional samples of basement rocks for detailed analysis, a stratigraphic drilling campaign was undertaken in the East Tennant region as part of the MinEx CRC’s National Drilling Initiative. Ten stratigraphic boreholes were drilled through the cover sequences and into basement for a total of nearly 4000 m, including over 1500 m of diamond cored basement rocks to be used for scientific purposes. Inorganic geochemical samples from East Tennant National Drilling Initiative boreholes were taken to characterise cover and basement rocks intersected during drilling. Two sampling approaches were implemented based on the rocks intersected: 1) Borehole NDIBK04 contained localised sulphide mineralisation and elevated concentrations of several economically-significant elements in portable X-ray fluorescence data. In order to understand the geochemical variability and distribution of elements important for mineral system characterisation, the entire basement interval was sampled at nominal one metre intervals. This spacing was reduced to between 0.5 and 0.25 m from 237 m to 263 m to better understand a more intense zone of mineralisation, and 2) Samples from boreholes NDIBK01, NDIBK02, NDIBK03, NDIBK05, NDIBK06, NDIBK07, NDIBK08, NDIBK09 and NDIBK10 were selected to capture lithological and geochemical variability to establish bulk rock geochemical compositions for further interpretation. Attempts were made to sample representative, lithologically consistent intervals. A total of 402 samples were selected for analysis. Sample preparation was completed at Geoscience Australia and Bureau Veritas, with all analyses performed by Bureau Veritas in Perth. All samples were submitted for X-ray fluorescence (XRF), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), FeO determination, and loss on ignition (LOI). Samples from borehole NDIBK04 also underwent total combustion C and S, and Pb collection fire assay by ICP-MS for determination of Au, Pt and Pd concentrations. This data release presents inorganic geochemistry data acquired on rock samples from the ten East Tennant National Drilling Initiative boreholes.

<div>Throughout geological history, marine organic-rich shales show variable but appreciable enrichment in uranium (U), < 5 to > 500 ppm. Here we report the results of high-energy resolution fluorescence detection (HERFD) x-ray absorption spectroscopy at U L3 and M4 edges to characterize U speciation in marine sediments.</div><div><br></div><div>We characterised U oxidation state in samples from the Cretaceous Toolebuc Formation of the Eromanga Basin, Australia. Nine samples were carbonaceous shales with high total organic carbon (TOC) content of 5.9 to 13.4 wt&nbsp;% and with low maturity organic matter. Two samples of coquinite were selected for comparison (TOC 0.3 and 2.4 wt %).</div><div><br></div><div>Our results suggest that a significant proportion of U in marine black shales (~20 to 30%) exists as U(VI) (Figures 1-2), despite the extremely reducing (anoxic to euxinic) conditions during sediment precipitation and diagenesis. Within individual samples, spot analyses indicate variation in the estimated oxidation state within a range of ~20% of U(VI). Uranium is unevenly distributed at mm to nanoscale. Nanoscale secondary ion mass spectrometry (NanoSIMS) reveals different associations that often coexist in single samples; nano-particulate uranium is associated with organic matter matrix or sulphide minerals, whereas phosphate minerals display diffuse uranium enrichment. The coquinite has a higher proportion of U(VI), consistent with the dysoxic depositional environment (Boreham and Powell, 1987).</div><div><br></div><div>The unexpectedly enhanced proportion of U(VI) relative to U(IV) within marine organic-rich shales implies that U might not be immediately fixed by reduction processes during sedimentation, but adsorbed by accumulating organic matter, at least in part as U(VI). This is consistent with the behaviour of uranium reported within the water column of the anoxic Black Sea (Anderson, 1989), experiments on U(VI) sorption by organic matter (e.g., Bhat et al., 2008), and previously documented redox state of U from continental organic-rich Eocene (56-34 Ma) sediments of paleochannel and lacustrine origin (Cumberland et al., 2018).</div><div><br></div><div>The results are significant for improving hydrocarbon exploration in known fields (covering the gap to a carbon-free economy without development of new greenfield oil provinces); economic geology (uranium, base-metal, and critical-metal deposits); and environmental management (evaluating potential mobilization of U by groundwaters).</div><div><br></div>This Abstract was submitted and presented to the 2023 Goldschmidt Conference Lyon, France (https://conf.goldschmidt.info/goldschmidt/2023/meetingapp.cgi)