<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>

<div>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 stratigraphic 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) 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 Georgina Basin carbonates.&nbsp;</div><div>Geoscience Australia has undertaken a range of investigations on the lithology, stratigraphy and geotechnical properties of NDI Carrara 1 as well as undertaking a range of analyses of about 500 physical samples recovered through the entire core. Analyses included geochronology, isotope studies, mineralogy, inorganic and organic geochemistry, petrophysics, geomechanics, thermal maturity and petroleum systems investigations.</div><div>Rock-Eval pyrolysis raw data undertaken by Geoscience Australia were reported in Butcher et al. (2021) on selected rock samples to establish their total organic carbon content, hydrocarbon-generating potential and thermal maturity. Interpretation of the Rock-Eval pyrolysis data concluded that a large portion of rocks within the Proterozoic section displayed unreliable Tmax values due to poorly defined S2 peaks resulting from high thermal maturity and low hydrogen content. In order to obtain more reliable Tmax values, Rock-Eval pyrolysis of selected isolated kerogens, where organic matter is concentrated and mineral matrix effects are removed, were conducted and the resulting data are presented in this report.&nbsp;</div><div><br></div>

The values and distribution patterns of the strontium (Sr) isotope ratio 87Sr/86Sr in Earth surface materials is of use in the geological, environmental and social sciences. Ultimately, the 87Sr/86Sr ratio of any mineral or biological material reflects its value in the rock that is the parent material to the local soil and everything that lives in and on it. In Australia, there are few large-scale surveys of 87Sr/86Sr available, and here we report on a new, low-density dataset using 112 catchment outlet (floodplain) sediment samples covering 529,000 km2 of inland southeastern Australia (South Australia, New South Wales, Victoria). The coarse (<2 mm) fraction of bottom sediment samples (depth ~0.6-0.8 m) from the National Geochemical Survey of Australia were fully digested before Sr separation by chromatography and 87Sr/86Sr determination by multicollector-inductively coupled plasma-mass spectrometry. The results show a wide range of 87Sr/86Sr values from a minimum of 0.7089 to a maximum of 0.7511 (range 0.0422). The median 87Sr/86Sr (± robust standard deviation) is 0.7199 (± 0.0112), and the mean (± standard deviation) is 0.7220 (± 0.0106). The spatial patterns of the Sr isoscape observed are described and attributed to various geological sources and processes. Of note are the elevated (radiogenic) values (≥~0.7270; top quartile) contributed by (1) the Palaeozoic sedimentary country rock and (mostly felsic) igneous intrusions of the Lachlan geological region to the east of the study area; (2) the Palaeoproterozoic metamorphic rocks of the central Broken Hill region; both these sources contribute fluvial sediments into the study area; and (3) the Proterozoic to Palaeozoic rocks of the Kanmantoo, Adelaide, Gawler and Painter geological regions to the west of the area; these sources contribute radiogenic material to the region mostly by aeolian processes. Regions of low 87Sr/86Sr (≤~0.7130; bottom quartile) belong mainly to (1) a few central Murray Basin catchments; (2) some Darling Basin catchments in the northeast; and (3) a few Eromanga geological region-influenced catchments in the northwest of the study area. The new spatial dataset is publicly available through the Geoscience Australia portal (https://portal.ga.gov.au/restore/cd686f2d-c87b-41b8-8c4b-ca8af531ae7e).

<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/)

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. The composition of the sediments reflects the dominant rock types in each catchment, with the generally resistant HMs largely preserving the mineralogical fingerprint of their host protoliths through the weathering-transport-deposition cycle. Heavy mineral presence/absence, absolute and relative abundance, and co-occurrence are metrics useful to map, discover and interpret catchment lithotype(s), geodynamic setting, magmatism, metamorphic grade, alteration and/or mineralization. Underpinning this vision is a pilot project, focusing on a subset from the national sediment sample archive, which is used to demonstrate the feasibility of the larger, national-scale project. We preview a bespoke, cloud-based mineral network analysis (MNA) tool to visualize, explore and discover relationships between HMs as well as between them and geological settings or mineral deposits. We envisage that the Heavy Mineral Map of Australia and MNA tool will contribute significantly to mineral prospectivity analysis and modeling, particularly for technology critical elements and their host minerals, which are central to the global economy transitioning to a more sustainable, lower carbon energy model. The full, peer-reviewed article can be found here: Caritat, P. de, McInnes, B.I.A., Walker, A.T., Bastrakov, E., Rowins, S.M., Prent, A.M. 2022. The Heavy Mineral Map of Australia: vision and pilot project. Minerals, 12(8), 961, https://doi.org/10.3390/min12080961

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>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)

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.

A regional hydrocarbon prospectivity study was undertaken in the onshore Canning Basin in Western Australia as part of the Exploring for the Future (EFTF) program, an Australian Government initiative dedicated to driving investment in resource exploration. As part of this program, significant work has been carried out to deliver new pre-competitive data including new seismic acquisition, drilling of a stratigraphic well, and the geochemical analysis of geological samples recovered from exploration wells. A regional, 872 km long 2D seismic line (18GA-KB1) acquired in 2018 by Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA), images the Kidson Sub-basin of the Canning Basin. In order to provide a test of geological interpretations made from the Kidson seismic survey, a deep stratigraphic well, Barnicarndy 1, was drilled in 2019 in a partnership between Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA) in the Barnicarndy Graben, 67 km west of Telfer, in the southwest Canning Basin. Drilling recovered about 2100 m of continuous core from 580 mRT to the driller’s total depth (TD) of 2680.53 mRT. An extensive analytical program was carried out to characterise the lithology, age and depositional environment of these sediments. This data release presents organic geochemical analyses undertaken on rock extracts obtained from cores selected from the Barnicarndy 1 well. The molecular and stable isotope data carbon and hydrogen will be used to understand the type of organic matter being preserved, the depositional facies and thermal maturity of the Lower Ordovician sedimentary rocks penetrated in this well. This information provides complementary information to other datasets including organic petrological and palynological studies.

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.