<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)

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.

NDI Carrara 1 is a deep stratigraphic drill hole completed in 2020 as part of the MinEx CRC National Drilling Initiative (NDI) in collaboration with Geoscience Australia and the Northern Territory Geological Survey. It is the first test of the Carrara Sub-Basin, a depocentre newly discovered in the South Nicholson region based on interpretation from seismic surveys (L210 in 2017 and L212 in 2019) recently acquired as part of the Exploring for the Future program. The drill hole intersected approximately 1120 m of Proterozoic sedimentary rocks unconformably overlain by 630 m of Cambrian Georgina Basin carbonates. Continuous cores recovered from 283 m to a total depth of 1750 m provide samples of the highest quality for a comprehensive geochemical program designed to inform on the energy and mineral prospectivity of the Carrara Sub-basin. Total Organic Carbon (TOC) contents from Rock-Eval pyrolysis of the Cambrian and Proterozoic sections demonstrate the potential for several thick black shales as source rocks and unconventional plays. Evidence for retained hydrocarbons included bituminous oil stains in centimetre-scale vugs within the Cambrian Georgina Basin and several oil bleeds within the Proterozoic section. The latter also contains surface gas with up to 2% methane concentrations measured within carbonaceous mudstones. Geochemical analyses of hydrocarbon shows highlight the occurrence of several petroleum systems operating in this frontier region. The results at NDI Carrara 1 offer the promise of a new exciting resource province in northern Australia.

<div>Geoscience Australia’s Exploring for the Future 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 Paleo to Mesoproterozoic Birrindudu Basin is an underexplored frontier basin located in northwestern Northern Territory and northeastern Western Australia. The Birrindudu Basin is a region of focus for the second phase of the EFTF program (2020–2024) as it contains strata of similar age to the prospective McArthur Basin, South Nicholson region and Mount Isa Province, but remains comparatively poorly understood.</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 WLMB001B, Birrindudu Basin, located in the northwest Northern Territory.</div><div><br></div><div>This ecat record releases the final report containing the results of fluid inclusion stratigraphy, thin section and microthermometry analyses, raw data files (*.LAS) and rock descriptions by FIT Schlumberger. Company reference number FI230004a.</div>

<div>Heavy minerals (HMs) are those with a specific gravity greater than 2.9 g/cc (e.g., anatase, zircon). They have been used successfully in mineral exploration programs outside Australia for decades [1 and refs therein]. Individual HMs and combinations, or co-occurrence, of HMs can be characteristic of lithology, degree of metamorphism, alteration, weathering or even mineralisation. These are termed indicator minerals, and have been used in exploration for gold, diamonds, mineral sands, nickel-copper, platinum group elements, volcanogenic massive sulfides, non-sulfide zinc, porphyry copper-molybdenum, uranium, tin-tungsten, and rare earth elements mineralization. Although there are proprietary HM sample assets held by industry in Australia, no extensive public-domain dataset of the natural distribution of HMs across the continent currently exists.</div><div> We describe a vision for a national-scale heavy mineral (HM) map generated through automated mineralogical identification and quantification of HMs contained in floodplain sediments from large catchments covering most of Australia [1]. These samples were collected as part of the National Geochemical Survey of Australia (NGSA; www.ga.gov.au/ngsa) and are archived in Geoscience Australia’s rock store. The composition of the sediments can be assumed to reflect the dominant rock and soil types within each catchment (and potentially those upstream), with the generally resistant HMs largely preserving the mineralogical fingerprint of their host protoliths through the weathering-transport-deposition cycle. </div><div> Underpinning this vision is a pilot project, focusing on a subset of NGSA to demonstrate the feasibility of the larger, national-scale project. Ten NGSA sediment samples were selected and both bulk and HM fractions were analysed for quantitative mineralogy using a Tescan® Integrated Mineral Analyzer (TIMA) at the John de Laeter Centre, Curtin University (Figure 1). Given the large and complex nature of the resultant HM dataset, we built a bespoke, cloud-based mineral network analysis (MNA) tool to visualise, explore and discover relationships between HMs, as well as between them and geological setting or mineral deposits. The pilot project affirmed our expectations that a rich and diverse mineralogical ecosystem will be revealed by expanding HM mapping to the continental scale. </div><div> A first partial data release in 2022 was the first milestone of the Heavy Mineral Map of Australia (HMMA) project. The area concerned is the Darling-Curnamona-Delamerian region of southeastern Australia, where the richly endowed Broken Hill mineral province lies. Here, we identified over 140 heavy minerals from 29 million individual mineral observations in 223 sediment samples. Using the MNA tool, one can quickly identify interesting base metal mineral associations and their spatial distributions (Figure 2).</div><div> We envisage that the Heavy Mineral Map of Australia and the MNA tool will contribute significantly to mineral prospectivity analysis and modelling in Australia, particularly for technology critical elements and their host minerals, which are central to the global economy transitioning to a more sustainable, decarbonised paradigm.</div><div><br></div>Figure 1. Distribution map of ten selected heavy minerals in the heavy mineral fractions of the ten NGSA pilot samples (pie charts), overlain on Australia’s geological regions (variable colors) [2]). Map projection: Albers equal area.</div><div><br></div><div>Figure 2. Graphical user interface for the Geoscience Australia MNA cloud-based visualization tool for the DCD project (https://geoscienceaustralia.shinyapps.io/HMMA-MNA/) showing the network for Zn minerals with the gahnite subnetwork highlighted (left) and the map of gahnite distribution (right).</div><div> <strong>References</strong></div><div>[1] Caritat et al., 2022, Minerals, 12(8), 961. https://doi.org/10.3390/min12080961 </div><div>[2] Blake &amp; Kilgour, 1998, Geosci Aust. https://pid.geoscience.gov.au/dataset/ga/32366 </div><div><br></div>This Abstract was submitted/presented to the 2022 Mineral Prospectivity and Exploration Targeting (MinProXT 2022) webinar, Freiburg, Germany, 01 - 03 November (www.minproxt.com)

<div>The push of mineral exploration under cover requires developing new geochemical exploration approaches. Detailed hydrogeochemistry addresses these needs and is valuable as a non-invasive mineral exploration technique that can identify lithological changes and dispersion signatures associated with mineralisation. Here we integrate whole-rock geochemistry and hydrogeochemistry to evaluate suitable geochemical tracers in groundwater for detecting phosphate and/or Pb-Zn style mineralisation in the Georgina Basin. The known Georgina Basin’s phosphate deposits are within the basin’s aquifers, providing groundwater near deposits greater exposure and opportunity for water-rock interactions with mineralised geology, resulting in trace element and isotope signatures of mineralisation at detectable levels. These tracers can then be applied elsewhere in the basin as a screening tool for detecting mineralisation. To achieve this, we collected rock geochemistry from the MinEx CRC East Tennant National Drilling Initiative Campaign (ME-ET) drillcore, and integrated it with nearby hydrogeochemistry (from the Northern Australia Hydrogeochemical Survey (NAHS)). </div><div><br></div><div>The NAHS was collected by Geoscience Australia as part of EFTF, which included 170 samples from Georgina Basin aquifers. This hydrogeochemistry dataset is high quality, due to robust sampling, QA/QC procedures and a comprehensive analysis suite, making it a useful tool for mineral exploration in the Georgina Basin. The ME-ET drilled 10 stratigraphic holes east of Tennant Creek, Northern Territory, in support of Geoscience Australia’s Exploring for the Future program (EFTF). Seventy six Georgina Basin rock samples were collected for whole rock geochemistry and a subset for Pb and Sr isotopes. Samples were selected to target: 1) background unmineralised lithostratigraphy, 2) intervals with groundwater intersections, and 3) transects through zones with anomalous concentrations of P, Pb, Zn and Cu, as identified by portable XRF analysis. </div><div><br></div><div>Initial exploratory data analysis of the hydrogeochemistry is conducted at various scales using principle component analysis and clustering approaches to identify the key attributes (major and trace elements, isotopes, hydrogeology etc.) that are associated with higher P content in the groundwater. These relationships are tested by comparing groundwater samples proximal (in depth and spatially) to high P compositions in the host rock, providing insight into the water-rock interactions taking place. Additionally, vertical whole rock geochemistry transects within the drill-holes are investigated to evaluate the trace element and/or isotopic features that are diagnostic of the enriched phosphate zones. We take the robust geochemical relationships identified from both approaches and apply them as tracers across the NAHS to flag areas of potential undiscovered mineralisation. As we will demonstrate, the NAHS can detect subtle or diluted mineralisation signatures, and underpins a revised understanding of phosphate mineral prospectivity in the Georgina Basin.</div> Abstract submitted and presented at 2023 Australian Earth Science Convention (AESC), Perth WA (https://2023.aegc.com.au/)

<p>The Roebuck Basin on Australia’s offshore north-western margin is the focus of a regional hydrocarbon prospectivity assessment being undertaken by the North West Margin Energy Studies Section (NWMES). 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. <p>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) and Dorado 1 (2018) in the Bedout Sub-basin demonstrate the presence of a petroleum system in Lower Triassic strata. The current study aims to better understand this new petroleum system and establish its extent. <p>As part of this program, compositional and isotopic analyses were undertaken by Geoscience Australia on gas samples from the wells Roc 1 and Roc 2 and data from these analyses are released in this dataset.

The Paleo- to Mesoproterozoic McArthur Basin and Mount Isa region of northern Australia (Figure 1) is richly-endowed with a range of deposit types (e.g., Ahmad et al., 2013; Geological Survey of Queensland, 2011). These include the basin-hosted base metal (Zn-Pb-Ag) deposits of the North Australian Zinc Belt, the richest zinc province in the world (Geological Survey of Queensland, 2011; Huston et al., 2006), as well as Cu (e.g., Mt Isa Copper) and IOCG (e.g., Ernest Henry) deposits (Geological Survey of Queensland, 2011). The giant size of the base metal deposits makes them attractive exploration targets and significant effort has been undertaken in understanding their genesis and setting and developing methodologies and data sets to aid in further discovery. As part of its Exploring for the Future program, Geoscience Australia is acquiring new, and reprocessing old, data sets to provide industry with new exploration tools for these basin-hosted Zn-Pb and Cu deposits, as well as iron-oxide copper-gold deposits. We have adopted a mineral systems approach (e.g., Huston et al., 2016) focussing on regional aspects such as source rocks, locations of mineral deposits, mineralisation haloes and footprints. Increased understanding of these aspects requires knowledge of the background variability of unaltered rocks within the basin. To assist in this we have undertaken a campaign of baseline geochemical studies, with over 800 new samples collected from sedimentary and igneous units of selected parts of the greater McArthur Basin–Mount Isa region. This has allowed us to document temporal and regional background geochemical (and mineralogical) variation within, and between sedimentary and igneous units. The main focus of this work was directed towards aspects of base metal mineralisation; a concurrent GA study (e.g., Jarrett et al., 2019) looking at aspects of hydrocarbon potential was undertaken in parallel. Appeared in Annual Geoscience Exploration Seminar (AGES) Proceedings, Alice Springs, Northern Territory 24-25 March 2020, p. 105

<div>Although heavy mineral exploration techniques have been successfully used as exploration vectors to ore deposits around the world, exploration case studies and pre-competitive datasets relevant to Australian conditions are relatively limited. The Heavy Mineral Map of Australia (HMMA) project is a novel analytical campaign to determine the abundance and distribution of heavy minerals (SG>2.9 g/cc) in 1315 floodplain sediment samples collected from catchments across Australia during Geoscience Australia’s National Geochemical Survey of Australia (NGSA) project. Archived NGSA samples, which originated from, on average, 60 to 80 cm depth in floodplain landforms, were sub-sampled and subjected to dense media separation and automated SEM-EDS analysis in the John de Laeter Centre at Curtin University. Mineral assay data from all 1315 drainage samples will be publicly released by the end of 2023. </div><div><br></div><div>An initial data package released in August 2022 contains mineralogical assay data for 223 samples from the Darling–Curnamona–Delamerian (DCD) region of south-eastern Australia. That package identified over 140 heavy minerals from 29 million individual mineral observations. The number of mineral observations generated during the project required development of a novel Mineral Network Analysis (MNA) tool to allow end users to discover, visualise and interpret mineral co-occurrence relationships, potentially useful in exploration vectoring and targeting. The MNA tool can also be used to rapidly search the heavy mineral database to locate observations of potential economic significance. The co-occurrence of Zn-minerals indicative of high-grade metamorphism of base metal mineralisation (e.g., gahnite (Zn-spinel), ecandrewsite (Zn-ilmenite) and zincostaurolite (Zn-aluminosilicate)) from the region surrounding Broken Hill demonstrated the utility of the method. Zn-mineral co-occurrences not associated with known mineralisation were also noted and may represent targeting opportunities. </div><div><br></div><div>Heavy mineral data from parts of Queensland are scheduled for a separate public release in December 2022 and will be presented at the conference.&nbsp;</div> This Abstract was submitted/presented to the 2023 Australian Exploration Geoscience Conference 13-18 Mar (https://2023.aegc.com.au/)