<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>Exploring for the Future (EFTF) is an Australian Government program led by Geoscience Australia, in partnership with state and Northern Territory governments, and aimed at stimulating exploration now to ensure a sustainable, long-term future for Australia through an improved understanding of the nation’s minerals, energy and groundwater resource potential. </div><div>The EFTF program is currently focused on eight interrelated projects, united in growing our understanding of subsurface geology. One of these projects, the Barkly–Isa–Georgetown project, will deliver new data and knowledge to assess the mineral and energy potential in undercover regions between Tennant Creek, Mount Isa and Georgetown. Building on the work completed in the first four years of the Exploring for the Future program (2016-2020), the project undertook stratigraphic drilling in the East Tennant and South Nicholson regions, in collaboration with MinEx CRC and the Northern Territory Geological Survey (NTGS). This work tests geological interpretations and the inferred mineral and energy potential of these covered regions. Geoscience Australia is undertaking a range of analyses on physical samples from these drill holes including geochemistry and geochronology. </div><div>The South Nicholson National Drilling Initiative (NDI) Carrara 1 drill hole is the first drillhole to intersect the Proterozoic rocks of the Carrara Sub-Basin, a depocentre newly discovered in the South Nicholson region based on interpretation from seismic surveys acquired as part of the EFTF. It is located on the western flanks of the Carrara Sub-basin on the South Nicholson Seismic line 17GA-SN1, reaching a total depth of 1751 m, intersecting ca. 630 m of Cambrian Georgina Basin overlying ca. 1100 m of Proterozoic carbonates, black shales and minor siliciclastics.</div><div>The NDI BK10 drill hole is the tenth drill hole drilled as part of the East Tennant project aimed to constrain the East Tennant basement geology and calibrate predictive mineral potential maps to further our understanding of the prospectivity of this region. NDI BK10 reached a depth of 766 m and intersected basement at 734 m. Overlying these basement metasediments of the Alroy Formation, the drillhole intersected about 440 m of Proterozoic rocks underlain by ca. 300 m rocks of Cambrian age from the Georgina Basin.</div><div>During coring of NDI Carrara 1 and NDI BK10, cores containing oil stains were identified and sent for geochemical analysis to Geoscience Australia. This report presents the geochemical data from these oil stains including biomarker and isotopic data.</div>

Geoscience Australia currently uses two commercial petroleum system modelling software packages, PetroMod https://www.software.slb.com/products/petromod and Zetaware http://www.zetaware.com, to undertake burial and thermal history modelling on wells in Australian sedimentary basins. From the integration of geological (age-based sedimentary packages, uplift and erosional events), petrophysical (porosity, permeability, and thermal conductivity) and thermal (downhole temperature, heat flow, vitrinite reflectance, and Tmax) input data, to name the most significant, a best-fit model of the time-temperature history is generated. Since the transformation of sedimentary organic matter (kerogen) into petroleum (oil and gas) is a chemical reaction, it is governed by chemical kinetics i.e. time and temperature (in the geological setting, pressure is of secondary importance). Thus, the use of chemical kinetics associated with a formation-specific, immature potential source rock (where available) from the basin of interest is considered a better practical approach rather than relying on software kinetic defaults, which are generally based on the chemical kinetics determined experimentally on Northern Hemisphere organic matter types. As part of the Offshore Energy Systems program hydrocarbons from the Lower Cretaceous Eumeralla Formation were selected where available from onshore wells; compositional kinetics (1-, 2-, 4- and 14-component (phase) kinetics) were undertaken by GeoS4, Germany. The phase kinetics approach is outlined in Appendix 1. This report provides the compositional kinetics for potential source rocks from the Lower Cretaceous Otway Group, Otway Basin, Australia. The kinetic data were used in the offshore petroleum system modelling reported in Schenk et al. (2021).

<div>The Heavy Mineral Map of Australia (HMMA) project1, part of Geoscience Australia’s Exploring for the Future program, determined the abundance and distribution of heavy minerals (HMs; specific gravity >2.9 g/cm3) in 1315 floodplain sediment samples obtained from Geoscience Australia’s National Geochemical Survey of Australia (NGSA) project2. Archived NGSA samples from floodplain landforms were sub-sampled with the 75-430 µm fraction subjected to dense media separation and automated mineralogy assay using a TESCAN Integrated Mineral Analysis (TIMA) instrument at Curtin University.</div><div><br></div><div>Interpretation of the massive number of mineral observations generated during the project (~150&nbsp;million mineral observations; 166 unique mineral species) required the development of a novel workflow to allow end users to discover, visualise and interpret mineral co-occurrence and spatial relationships. Mineral Network Analysis (MNA) has been shown to be a dynamic and quantitative tool capable of revealing and visualizing complex patterns of abundance, diversity and distribution in large mineralogical data sets3. To facilitate the application of MNA for the interpretation of the HMMA dataset and efficient communication of the project results, we have developed a Mineral Network Analysis for Heavy Minerals (MNA4HM) web application utilising the ‘Shiny’ platform and R package. The MNA4HM application is used to reveal (1) the abundance and co-occurrences of heavy minerals, (2) their spatial distributions, and (3) their relations to first-order geological and geomorphological features. The latter include geological provinces, mineral deposits, topography and major river basins. Visualisation of the mineral network guides parsimonious yet meaningful mapping of minerals typomorphic of particular geological environments or mineral systems. The mineralogical dataset can be filtered or styled based on mineral attributes (e.g., simplified mineralogical classes) and properties (e.g., chemical composition).</div><div><br></div><div>In this talk we will demonstrate an optimised MNA4HM workflow (identification à mapping à interpretation) for exploration targeting selected critical minerals important for the transition to a lower carbon global economy. </div><div><br></div><div>The MNA4HM application is hosted at https://geoscienceaustralia.shinyapps.io/mna4hm and is available for use by the geological community and general public.</div> This Abstract was submitted and presented to the 2023 Goldschmidt Conference Lyon, France (https://conf.goldschmidt.info/goldschmidt/2023/meetingapp.cgi)

Rapid, efficient, and accurate prediction of mineral occurrence that takes uncertainty into 20 account is essential to optimise defining exploration targets. Traditional approaches to mineral 21 potential mapping often fail to fully appreciate spatial uncertainties of input predictors and their 22 spatial cross-correlation. In this study a stochastic technique based on multivariate 23 geostatistical simulations and ensemble tree-based learners is introduced for predicting and 24 uncertainty quantification of mineral exploration targets. The technique is tested on a synthetic 25 case inspired by the characteristics of a hydrothermal mineral system model and a real-world 26 dataset from the Yilgarn Craton in Western Australia. Results from the two cases proved the 27 superior performance and robustness of the proposed stochastic technique, especially when 28 dealing with high dimensional and large data sets. <b>Citation:</b> Talebi, H., Mueller, U., Peeters, L.J.M. et al. Stochastic Modelling of Mineral Exploration Targets. <i>Math Geosci </i>54, 593–621 (2022). https://doi.org/10.1007/s11004-021-09989-z

Multi-element geochemical surveys of rocks, soils, stream/lake/floodplain sediments, and regolith are typically carried out at continental, regional and local scales. The chemistry of these materials is defined by their primary mineral assemblages and their subsequent modification by comminution and weathering. Modern geochemical datasets represent a multi-dimensional geochemical space that can be studied using multivariate statistical methods from which patterns reflecting geochemical/geological processes are described (process discovery). These patterns form the basis from which probabilistic predictive maps are created (process validation). Processing geochemical survey data requires a systematic approach to effectively interpret the multi-dimensional data in a meaningful way. Problems that are typically associated with geochemical data include closure, missing values, censoring, merging, levelling different datasets, and adequate spatial sample design. Recent developments in advanced multivariate analytics, geospatial analysis and mapping provide an effective framework to analyze and interpret geochemical datasets. Geochemical and geological processes can often be recognized through the use of data discovery procedures such as the application of principal component analysis. Classification and predictive procedures can be used to confirm lithological variability, alteration, and mineralization. Geochemical survey data of lake/till sediments from Canada and of floodplain sediments from Australia show that predictive maps of bedrock and regolith processes can be generated. Upscaling a multivariate statistics-based prospectivity analysis for arc related Cu-Au mineralization from a regional survey in the southern Thomson Orogen in Australia to the continental scale, reveals a number of regions with similar (or stronger) multivariate response and hence potentially similar (or higher) mineral potential throughout Australia. <b>Citation:</b> E. C. Grunsky, P. de Caritat; State-of-the-art analysis of geochemical data for mineral exploration. <i>Geochemistry: Exploration, Environment, Analysis</i> 2019; 20 (2): 217–232. doi: https://doi.org/10.1144/geochem2019-031 This article appears in multiple journals (Lyell Collection & GeoScienceWorld)

The unexpected discovery of oil in Triassic sedimentary rocks of the Phoenix South 1 well on Australia’s North West Shelf (NWS) has catalysed exploration interest in pre-Jurassic plays in the region. Subsequent neighbouring wells Roc 1–2, Phoenix South 2–3 and Dorado 1–3 drilled between 2015 and 2019 penetrated gas and/or oil columns, with the Dorado field containing one of the largest oil resources found in Australia in three decades. This study aims to understand the source of the oils and gases of the greater Phoenix area, Bedout Sub-basin using a multiparameter geochemical approach. Isotopic analyses combined with biomarker data confirm that these fluids represent a new Triassic petroleum system on the NWS unrelated to the Lower Triassic Hovea Member petroleum system of the Perth Basin. The Bedout Sub-basin fluids were generated from source rocks deposited in paralic environments with mixed type II/III kerogen, with lagoonal organofacies exhibiting excellent liquids potential. The Roc 1–2 gases and the Phoenix South 1 oil are likely sourced proximally by Lower–Middle Triassic TR10–TR15 sequences. Loss of gas within the Phoenix South 1 fluid due to potential trap breach has resulted in the formation of in-place oil. These discoveries are testament to new hydrocarbon plays within the Lower–Middle Triassic succession on the NWS.

The Roebuck Basin on Australia’s offshore north-western margin is the focus of a regional hydrocarbon prospectivity assessment being undertaken by the Offshore Energy Systems Section. This offshore program is designed to produce pre-competitive information to assist with the evaluation of the hydrocarbon resource potential of the central North West Shelf and attract exploration investment to Australia. The recent oil and gas discoveries at Phoenix South 1 (2014), Roc 1 (2015-16), Roc 2 (2016), Phoenix South 2 (2016), Phoenix South 3 (2018), Dorado 1 (2018) and Dorado 2–3 (2019) in the Bedout Sub-basin demonstrate the presence of a petroleum system in Lower Triassic strata (Grosjean et al., 2021; Rollet et al., 2019). As part of this program, a range of organic geochemical analyses were acquired on petroleum fluids from the Dorado 1 and Roc 2 wells with these data released in this report.

Geoscience Australia's Australian National Hydrocarbon Geochemistry Data Collection comprises Oracle database tables from the Organic Geochemistry (ORGCHEM) schema and derivative information in the Petroleum Systems Summary database (Edwards et al., 2020, 2023; Edwards and Buckler, 2024). The ORGCHEM schema includes organic geochemistry, organic petrology and stable isotope database tables that capture the analytical results from sample-based datasets used for the discovery and evaluation of sediment-hosted resources. A focus is to capture open file data relevant to energy (i.e., petroleum and hydrogen) exploration, including source rocks, crude oils and natural gases from both onshore and offshore Australian sedimentary basins. The database tables also include complementary physical properties and complementary inorganic analyses on sedimentary rocks and hydrocarbon-based earth materials. The data are produced by a wide range of destructive analytical techniques conducted on samples submitted by industry under legislative requirements, as well as on samples collected by research projects undertaken by Geoscience Australia, other government agencies and scientific institutions. Some of these results have been generated by Geoscience Australia, whereas other data are compiled from service company reports, well completions reports, government reports, published papers and theses. The data is non-confidential and available for use by Government, the energy exploration industry, research organisations and the community. The Petroleum Systems Summary database stores the compilation of the current understanding of petroleum systems information, including the statistical evaluation of the analytical data by basin across the Australian continent. <b>Value: </b>These data in the ORGCHEM database tables comprise the raw organic geochemistry, organic petrological and stable isotopic values generated for Australian source rocks, crude oils and natural gases and is the only public comprehensive database at the national scale. The raw data are used as input values to other studies, such as basin analysis, petroleum systems evaluation and modelling, resource assessments, enhanced oil recovery projects, and national mapping projects. Derived datasets and value-add products are created based on calculated values and interpretations to provide information on the subsurface petroleum prospectivity of the Australian continent, as summarised in the Petroleum Systems Summary database. The data collection aspires to build a national scale understanding of Australia's petroleum and hydrogen resources. This data collection is useful to government for evidence-based decision making on sediment-hosted energy resources and the energy industry for de-risking both conventional and unconventional hydrocarbon exploration programs, hydrogen exploration programs, and carbon capture, utilisation and storage programs. <b>Scope: </b>The database initially comprised organic geochemical and organic petrological data on organic-rich sedimentary rocks, crude oils and natural gas samples sourced from petroleum wells drilled in the onshore and offshore Australian continent, including those held in the Australian National Offshore Wells Data Collection. Over time, other sample types (e.g., fluid inclusions, mineral veins, bitumen) from other borehole types (e.g., minerals, stratigraphic including the Integrated Ocean Drilling Program, and coal seam gas), marine dredge samples and field sites (outcrop, mines, surface seepage samples, coastal bitumen strandings) have been analysed for their molecular and stable isotopic chemical compositions and are captured in the databases. The organic geochemical database tables and derivative data compiled in the Petroleum Systems Summary database are delivered by web services and analytical tools in the <a href="https://portal.ga.gov.au/">Geoscience Australia Data Discovery Portal </a> and specifically in the <a href="https://portal.ga.gov.au/persona/sra">Source Rock and Fluid Atlas Persona</a>. These web services enable interrogation of source rock and petroleum fluids data within boreholes and from field sites and facilitate correlation of these elements of the petroleum system within and between basins. <b>Reference</b> Edwards, D.S., Buckler, T., Grosjean, E. & Boreham, C.J. 2024. Organic Geochemistry (ORGCHEM) Database. Australian Source Rock and Fluid Atlas. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/149422 Edwards, D., Hawkins, S., Buckler, T., Cherukoori, R., MacFarlane, S., Grosjean, E., Sedgmen, A., Turk, R. 2023. Petroleum Systems Summary database. Geoscience Australia, Canberra. https://dx.doi.org/10.26186/148979 Edwards, D.S., MacFarlane, S., Grosjean, E., Buckler, T., Boreham, C.J., Henson, P., Cherukoori, R., Tracey-Patte, T., van der Wielen, S.E., Ray, J., Raymond, O. 2020. Australian source rocks, fluids and petroleum systems – a new integrated geoscience data discovery portal for maximising data potential. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/133751.

<div>Geoscience Australia’s Exploring for the Future (EFTF) program provides precompetitive information to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. By gathering, analysing and interpreting new and existing precompetitive geoscience data and knowledge, we are building a national picture of Australia’s geology and resource potential.</div><div><br></div><div>The Stansbury Basin is a relatively underexplored basin in southern South Australia. Stansbury West 1 was drilled on the east coast of Yorke Peninsula to test the basal Permian sands and Paleozoic carbonate known to contain traces of hydrocarbon gas and residual oil. The well encountered no significant hydrocarbons and was abandoned as dry. A known occurrence of hydrogen-rich natural gas was discovered nearly a century ago in a well to the north of Stansbury West 1. Also potential hydrogen gas enrichment in the near-surface in the surrounds of the Stansbury West 1 drillhole has been proposed using satellite imagery and land surface features.</div><div><br></div><div>The study of natural hydrogen gas occurrences is a focus for the second phase of the EFTF program (2020–2024) and the fluid inclusion stratigraphy (FIS) technique of Fluid Inclusion Technology (Schlumberger) provides a convenient method to measure the well's complete downhole section for both hydrocarbon non-hydrocarbon gases that have been geologically trapped in fluid inclusions and then mechanically released in the laboratory.</div><div><br></div><div>Geoscience Australia have undertaken (via the service provider, FIT Schlumberger) stratigraphic reconstructions of bulk volatile chemistry from fluid inclusions from the drillhole Stansbury West 1, Stansbury Basin. FIS analysis was performed on 270 cuttings and core samples from 15.24 to 1743.53 metres, including 4.9 metres of Archean gneiss and granitic basement at the base of the drillhole.</div><div><br></div><div>This ecat record releases the final report containing the results of fluid inclusion stratigraphy and thin section analyses, raw data files (*.LAS) and rock descriptions by FIT Schlumberger (Company reference number FI220025a).</div>