<div>The soil gas database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases for gas analyses undertaken by Geoscience Australia's laboratory on soil samples taken from shallow (down to 1 m below the surface) percussion holes. Data includes the percussion hole field site location, sample depth, analytical methods and other relevant metadata, as well as the molecular and isotopic compositions of the soil gas with air included in the reported results. Acquisition of the molecular compounds are by gas chromatography (GC) and the isotopic ratios by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The concentrations of argon (Ar), carbon dioxide (CO₂), nitrogen (N₂) and oxygen (O₂) are given in mole percent (mol%). The concentrations of carbon monoxide (CO), helium (He), hydrogen (H₂) and methane (C₁, CH₄) are given in parts per million (ppm). Compound concentrations that are below detection limit (BDL) are reported as the value -99999. The stable carbon (¹³C/¹²C) and nitrogen (¹⁵N/¹⁴N) isotopic ratios are presented in parts per mil (‰) and in delta notation as δ¹³C and δ¹⁵N, respectively.</div><div><br></div><div>Determining the individual sources and migration pathways of the components of natural gases found in the near surface are useful in basin analysis with derived information being used to support exploration for energy resources (petroleum and hydrogen) and helium in Australian provinces. These data are collated from Geoscience Australia records with the results being delivered in the Soil Gas web services on the Geoscience Australia Data Discovery portal at https://portal.ga.gov.au which will be periodically updated.</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 pyrolysis-reflectance tie database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases, which combine key properties related to thermal maturity. These data are typically used as input parameters in basin analysis and petroleum systems modelling to assist with the discovery and evaluation of sediment-hosted energy resources. The programmed pyrolysis analyses and the maceral reflectance analyses undertaken using reflected light microscopy are conducted on rock samples, either as cores, cuttings or rock chips, taken from boreholes and field sites in Australian sedimentary basins. The full datasets are available in the pyrolysis, vitrinite reflectance, maceral reflectance and organoclast maturity web services. These analyses are performed by various laboratories in service and exploration companies, Australian government institutions and universities using a range of instruments.</div><div><br></div><div>These data are collated from destructive analysis reports (DARs), well completion reports (WCRs), and literature. The data are delivered in the Combined Pyrolysis and Vitrinite Reflectance web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</div>

<b>Organic Geochemistry (ORGCHEM) Schema. Australian Source Rock and Fluid Atlas</b> The databases tables held within Geoscience Australia's Oracle Organic Geochemistry (ORGCHEM) Schema, together with other supporting Oracle databases (e.g., Borehole database (BOREHOLE), Australian Stratigraphic Units Database (ASUD), and the Reservoir, Facies and Shows (RESFACS) database), underpin the Australian Source Rock and Fluid Atlas web services and publications. These products provide information in an Australia-wide geological context on organic geochemistry, organic petrology and stable isotope data related primarily to sedimentary rocks and energy (petroleum and hydrogen) sample-based datasets used for the discovery and evaluation of sediment-hosted resources. The sample data provide the spatial distribution of source rocks and their derived petroleum fluids (natural gas and crude oil) taken from boreholes and field sites in onshore and offshore Australian provinces. Sample depth, stratigraphy, analytical methods, and other relevant metadata are also supplied with the analytical results. Sedimentary rocks that contain organic matter are referred to as source rocks (e.g., organic-rich shale, oil shale and coal) and the organic matter within the rock matrix that is insoluble in organic solvents is named kerogen. The data in the ORGCHEM schema 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, state and territory geological organisations and scientific institutions including the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and universities. Data entered into the database tables are commonly sourced from both the basic and interpretive volumes of well completion reports (WCR) provided by the petroleum well operator to either the state and territory governments or, for offshore wells, to the Commonwealth Government under the Offshore Petroleum and Greenhouse Gas Storage Act (OPGGSA) 2006 and previous Petroleum (submerged Lands) Act (PSLA) 1967. Data are also sourced from analyses conducted by Geoscience Australia’s laboratory and its predecessor organisations, the Australian Geological Survey Organisation (AGSO) and the Bureau of Mineral Resources (BMR). Other open file data from company announcements and reports, scientific publications and university theses are captured. The ORGCHEM database was created in 1990 by the BMR in response to industry requests for organic geochemistry data, featuring pyrolysis, vitrinite reflectance and carbon isotopic data (Boreham, 1990). Funding from the Australian Petroleum Cooperative Research Centre (1991–2003) enabled the organic geochemical data to be made publicly available at no cost via the petroleum wells web page from 2002 and included BOREHOLE, ORGCHEM and the Reservoir, Facies and Shows (RESFACS) databases. Investment by the Australian Government in Geoscience Australia’s Exploring for the Future (EFTF) program facilitated technological upgrades and established the current web services (Edwards et al., 2020). The extensive scope of the ORGCHEM schema has led to the development of numerous database tables and web services tailored to visualise the various datasets related to sedimentary rocks, in particular source rocks, crude oils and natural gases within the petroleum systems framework. These web services offer pathways to access the wealth of information contained within the ORGCHEM schema. Web services that facilitate the characterisation of source rocks (and kerogen) comprise data generated from programmed pyrolysis (e.g., Hawk, Rock-Eval, Source Rock Analyser), pyrolysis-gas chromatography (Py-GC) and kinetics analyses, and organic petrological studies (e.g., quantitation of maceral groups and organoclasts, vitrinite reflectance measurements) using reflected light microscopy. Collectively, these data are used to establish the occurrence of source rocks and the post-burial thermal history of sedimentary basins to evaluate the potential for hydrocarbon generation. Other web services provide data to characterise source rock extracts (i.e., solvent extracted organic matter), fluid inclusions and petroleum (e.g., natural gas, crude oil, bitumen) through the reporting of their bulk properties (e.g., API gravity, elemental composition) and molecular composition using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Also reported are the stable isotope ratios of carbon, hydrogen, nitrogen, oxygen and sulfur using gas chromatography-isotope ratio mass spectrometry (GC-IRMS) and noble gas isotope abundances using ultimate high-resolution variable multicollection mass spectrometry. The stable isotopes of carbon, oxygen and strontium are also reported for sedimentary rocks containing carbonate either within the mineral matrix or in cements. Interpretation of these data enables the characterisation of petroleum source rocks and identification of their derived petroleum fluids, which comprise two key elements of petroleum systems analysis. Understanding a fluid’s physical properties and molecular composition are prerequisites for field development. The composition of petroleum determines its economic value and hence why the concentration of hydrocarbons (methane, wet gases, light and heavy oil) and hydrogen, helium and argon are important relative to those of nitrogen, carbon dioxide and hydrogen sulfide for gases, and heterocyclic compounds (nitrogen, oxygen or sulfur) found in the asphaltene, resin and polar fractions of crude oils. The web services and tools in the Geoscience Australia Data Discovery Portal (https://portal.ga.gov.au/), and specifically in the Source Rock and Fluid Atlas Persona (https://portal.ga.gov.au/persona/sra), allow the users to search, filter and select data based on various criteria, such as basin, formation, sample type, analysis type, and specific geochemical parameters. The web map services (WMS) and web feature services (WFS) enable the user to download data in a variety of formats (csv, Json, kml and shape file). The Source Rock and Fluid Atlas supports national resource assessments. The focus of the atlas is on the exploration and development of energy resources (i.e., petroleum and hydrogen) and the evaluation of resource commodities (i.e., helium and graphite). Some data held in the ORGCHEM tables are used for enhanced oil recovery and carbon capture, storage and utilisation projects. The objective of the atlas is to empower people to deliver Earth science excellence through data and digital capability. It benefits users who are interested in the exploration and development of Australia's energy resources by: • Providing a comprehensive and reliable source of information on the organic geochemistry of Australian source rocks • Enhancing the understanding of the spatial distribution, quality, and maturity of petroleum source rocks. • Facilitating the mapping of total petroleum and hydrogen systems and the assessment of the petroleum and hydrogen resource potential and prospectivity of Australian basins. • Facilitating the mapping of gases (e.g., methane, helium, carbon dioxide) within the geosphere as part of the transition to clean energy. • Enabling the integration and comparison of data from diverse sources and various acquisition methods, such as geological, geochemical, geophysical and geospatial data. • Providing data for integration into enhanced oil recovery and carbon capture, storage and utilisation projects. • Improving the accessibility and usability of data through user-friendly and interactive web-based interfaces. • Promoting the dissemination and sharing of data among Government, industry and community stakeholders. <b>References</b> Australian Petroleum Cooperative Research Centre (APCRC) 1991-2003. Australian Petroleum CRC (1991 - 2003), viewed 6 May 2024, https://www.eoas.info/bib/ASBS00862.htm and https://www.eoas.info/biogs/A001918b.htm#pub-resources Boreham, C. 1990. ORGCHEM Organic geochemical database. BMR Research Newsletter 13. Record 13:10-10. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/90326 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. <b>Citation</b> Edwards, D., Buckler, T. 2024. Organic Geochemistry (ORGCHEM) Schema. Australian Source Rock and Fluid Atlas. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/149422

<div>The bulk oils database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases for the bulk properties of petroleum liquids (e.g., condensate, crude oil, bitumen) sampled from boreholes and field sites. The analyses are performed by various laboratories in service and exploration companies, Australian government institutions, and universities using a range of instruments. Petroleum is composed primarily of hydrocarbons (carbon and hydrogen) with minor quantities of heterocyclic compounds containing either nitrogen, oxygen or sulfur. Data includes the borehole or field site location, sample depth, shows and tests, stratigraphy, analytical methods, other relevant metadata, and various data types including; API gravity, elemental composition and photographs of the samples. The stable carbon (¹³C/¹²C) and hydrogen (²H/¹H) isotopic ratios of crude oil and derivative saturated and aromatic hydrocarbon fractions are presented in parts per mil (‰) and in delta notation as &delta;¹³C and &delta;²H, respectively. Results are also included from methods that separate crude oils into bulk components, such as the quantification of saturated hydrocarbon, aromatic hydrocarbon, resin, and asphaltene (SARA) fractions according to their polarity.</div><div><br></div><div>These data provide information about the petroleum fluid’s composition, source, thermal maturity, secondary alteration, and fluid migration pathways. They are also useful for enhanced oil recovery assessments, petroleum systems mapping and basin modelling. Hence, these sample-based datasets are used for the discovery and evaluation of sediment-hosted resources. Some data are generated in Geoscience Australia’s laboratory and released in Geoscience Australia records. Data are also collated from destructive analysis reports (DARs), well completion reports (WCRs), and literature. The bulk oils data are delivered in the Petroleum Bulk Properties and Stable Isotopes web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</div>

<div>The pyrolysis-gas chromatography database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) database and supporting oracle databases for open system pyrolysis-gas chromatography (pyrolysis-GC) analyses performed on either source rocks or kerogen samples taken from boreholes and field sites. Sedimentary rocks that contain organic matter are referred to as source rocks (e.g., organic-rich shale, oil shale and coal) and the organic matter within the rock matrix that is insoluble in organic solvents is named kerogen. The analyses are undertaken by various laboratories in service and exploration companies using a range of instruments. Data includes the borehole or field site location, sample depth, stratigraphy, analytical methods, other relevant metadata, and the molecular composition of the pyrolysates. The concentrations of the aliphatic hydrocarbon, aromatic hydrocarbon and organic sulfur compounds are given in several units of measure [e.g., percent (resolved compounds) in the S2 peak (wt% S2), milligrams per gram of rock (mg/g rock), micrograms per gram of kerogen (mg/g kerogen) etc.].</div><div><br></div><div>These data are used to determine the organic richness, kerogen type and thermal maturity of source rocks in sedimentary basins. The results are used as input parameters in basin analysis and petroleum systems modelling to evaluate the potential for hydrocarbon generation in a sedimentary basin. These data are collated from destructive analysis reports (DARs), well completion reports (WCRs) and literature. The data are delivered in the Source Rock Pyrolysis-Gas Chromatography web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</div><div><br></div>

<div>The noble gas database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases for molecular and noble gas isotopic analyses on natural gases sampled from boreholes and fluid inclusion gases from rocks sampled in boreholes and field sites. Data includes the borehole or field site location, sample depths, shows and tests, stratigraphy, analytical methods, other relevant metadata, and the molecular and noble gas isotopic compositions for the natural gas samples. The molecular data are presented in mole percent (mol%) and cubic centimetres (at Standard Pressure and Temperature) per cubic centimetre (ccSTP/cc). The noble gas isotopic values that can be measured are; Helium (He, ³He, ⁴He), Neon (Ne, ²⁰Ne, ²¹Ne, ²²Ne), Argon (Ar, ³⁶Ar, ³⁸Ar, ⁴⁰Ar), Krypton (Kr, ⁷⁸Kr, ⁸⁰Kr, ^82<Kr, ⁸³Kr, ⁸⁴Kr, ⁸⁶Kr) and Xenon (Xe, ¹²⁴Xe, ¹²⁶Xe, ¹²⁸Xe, ¹²⁹Xe, ¹³⁰Xe, ¹³¹Xe, ¹³²Xe, ¹³⁴Xe, ¹³⁶Xe) which are presented in cubic micrometres per cubic centimetre (mcc/cc), cubic nanometres per cubic centimetre (ncc/cc) and cubic picometres per cubic centimetre (pcc/cc). Acquisition of the molecular compounds are by gas chromatography (GC) and the isotopic ratios by mass spectrometry (MS). Compound concentrations that are below the detection limit (BDL) are reported as the value -99999.</div><div><br></div><div>These data provide source information about individual compounds in natural gases and can elucidate fluid migration pathways, irrespective of microbial activity, chemical reactions and changes in oxygen fugacity, which are useful in basin analysis with derived information being used to support Australian exploration for energy resources and helium. These data are collated from Geoscience Australia records and well completion reports. The noble gas data for natural gases and fluid inclusion gases are delivered in the Noble Gas Isotopes web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</div><div><br></div><div><br></div>

<div><strong>Output type: </strong>Exploring for the Future Extended Abstract</div><div><br></div><div><strong>Short abstract: </strong>Australian sediment-hosted mineral systems play a crucial role in providing base metals and critical minerals essential for the global low-carbon economy. The Georgina Basin has the key components for forming and preserving a sediment-hosted Zn-Pb mineral system, but historically has been considered ‘cover’ to deeper, more prospective Proterozoic basement rocks. Thus, the basin has remained relatively under-explored, with many questions yet to be resolved on its sediment-hosted Zn-Pb mineral system and prospectivity for Zn-Pb. Utilising new whole-rock and isotope geochemistry of the Georgina Basin from recently drilled holes in the Northern Territory, we demonstrate the sensitivity of local redox boundaries to detect regional mineralisation. Two geochemically enriched zones have been identified and interpreted as redox interfaces which have trapped and concentrated metals from the surrounding basin, a ‘supergene zone’ and a ‘water intercept zone’. The ‘supergene zone’ is a paleo water table horizon, while the ‘water intercept zone’ is an active redox front at the uppermost part of the Cambrian Limestone Aquifer. The enrichment of these redox zones is consistent across multiple drill holes, reaching up to 395 ppm Pb and 1550 ppm Zn. Additionally, the Pb isotopes of high-Pb and sulfidic intervals have a highly radiogenic character (206Pb/204Pb ~22.0–23.0) that is diagnostic of Georgina Basin’s Mississippi Valley-type Zn-Pb mineralisation. Taken together, these results suggest there may be buried mineralisation in this part of the Georgina Basin, as well as highlight the potential of these redox interfaces as a regional reconnaissance target for exploration.</div><div><br></div><div><strong>Citation: </strong>Schroder I.F., Huston D. & de Caritat P., 2024. The geochemistry of redox interfaces for insights into Zn-Pb prospectivity in the Georgina Basin. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://doi.org/10.26186/149116 </div>

<div>Strontium isotopes (87Sr/86Sr) are useful in the earth sciences (e.g. recognising geological provinces, studying geological processes) as well in archaeological (e.g. informing on past human migrations), palaeontological/ecological (e.g. investigating extinct and extant taxa’s dietary range and migrations) and forensic (e.g. validating the origin of drinks and foodstuffs) sciences. Recently, Geoscience Australia and the University of Wollongong have teamed up to determine 87Sr/86Sr ratios in fluvial sediments selected mostly from the low-density National Geochemical Survey of Australia (NGSA; www.ga.gov.au/ngsa). The present study targeted the Yilgarn geological region in southwestern Australia. The samples were mostly taken from a depth of ~60-80 cm (Bottom Outlet Sediments, BOS) in floodplain deposits at or near the outlet of large catchments (drainage basins). A small number of surface (0-10 cm) samples (Top Outlet Sediments, TOS) were also included in the study. For all, a coarse grain-size fraction (<2 mm) was air-dried, sieved, milled then digested (hydrofluoric acid + nitric acid followed by aqua regia) to release total strontium. Overall, 107 NGSA BOS < 2 mm and 13 NGSA TOS < 2 mm were analysed for Sr isotopes. Given that there are ~10 % field duplicates in the NGSA, all those samples originate from within 97 NGSA catchments, which together cover 533 000 km2 of southwestern Australia. Preliminary results for the BOS samples demonstrate a wide range of strontium isotopic values (0.7152 < 87Sr/86Sr < 1.0909) over the survey area, reflecting a large diversity of source rock lithologies, geological processes and bedrock ages. Spatial distribution of 87Sr/86Sr shows coherent (multi-point anomalies and smooth gradients), large-scale (>100 km) patterns that appear to be consistent, in many places, with surface geology, regolith/soil type and/or nearby outcropping bedrock. For instance, catchments in the western and central Yilgarn dominated by felsic intrusive basement geology have radiogenic 87Sr/86Sr signatures in the floodplain sediments consistent with published whole-rock data. Similarly, unradiogenic signatures in sediments in the eastern Yilgarn are in agreement with published whole-rock data. Our results to-date indicate that incorporating soil/regolith strontium isotopes in regional, exploratory geoscience investigations can help identify basement rock types under (shallow) cover, constrain surface processes (e.g. weathering, dispersion), and, potentially, recognise components of mineral systems. Furthermore, the resulting strontium isoscape and model derived therefrom can also be utilised in archaeological, paleontological and ecological studies that aim to investigate past and modern animal (including humans) dietary habits and migrations.&nbsp; The new spatial dataset is publicly available through the Geoscience Australia portal https://portal.ga.gov.au/.</div>

<div>The bulk source rock database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases for the bulk properties of sedimentary rocks that contain organic matter and fluid inclusions taken from boreholes and field sites. The analyses are performed by various laboratories in service and exploration companies, Australian government institutions, and universities, using a range of instruments. Sedimentary rocks that contain organic matter are typically referred to as source rocks (e.g., organic-rich shale, oil shale and coal) and the organic matter within the rock matrix that is insoluble in organic solvents is named kerogen. Data includes the borehole or field site location, sample depth, stratigraphy, analytical methods, other relevant metadata, and various data types including; elemental composition, and the stable isotopes of carbon, hydrogen, nitrogen, and sulfur. Results are also included from methods that separate the extractable organic matter (EOM) from rocks into bulk components, such as the quantification of saturated hydrocarbon, aromatic hydrocarbon, resin and asphaltene (SARA) fractions according to their polarity. The stable carbon (¹³C/¹²C) and hydrogen (²H/¹H) isotopic ratios of the EOM and derivative hydrocarbon fractions, as well as fluid inclusion oils, are presented in delta notation (i.e., &delta;¹³C and &delta;²H) in parts per mil (‰) relative to the Vienna Peedee Belemnite (VPDB) standard.</div><div><br></div><div>These data are used to determine the molecular and isotopic compositions of organic matter within rocks and associated fluid inclusions and evaluate the potential for hydrocarbon generation in a basin. Some data are generated in Geoscience Australia’s laboratory and released in Geoscience Australia records. Data are also collated from destructive analysis reports (DARs), well completion reports (WCRs), and literature. The bulk data for sedimentary rocks are delivered in the Source Rock Bulk Properties and Stable Isotopes web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</div>