<div>High purity quartz (HPQ) is the only naturally occurring and economically viable source for the production of silicon. Silicon is a critical mineral, and a key component in modern technologies such as semiconductors and photovoltaic cells. Critical minerals support the move towards a greater reliance on electrification, renewable energy sources and economic security. The global transition to net zero carbon emissions means there is a growing need for new discoveries of HPQ to supply the silicon production chain. High purity quartz deposits are identified in a multitude of geological settings, including pegmatites, hydrothermal veins, sedimentary accumulations and quartzite; however, deposits of sufficient volume and quality are rare. Quartz is abundant throughout Australia, but the exploration and discovery of HPQ occurrences is notably under-reported, making assessment of the HPQ potential in Australia extremely difficult. This paper presents a much-needed summary of the state of the HPQ industry, exploration and deposit styles in Australia. <b>Citation:</b> Jennings, A., Senior, A., Guerin, K., Main, P., & Walsh, J. (2024). A review of high-purity quartz for silicon production in Australia. <i>Australian Journal of Earth Sciences</i>, 1–13. https://doi.org/10.1080/08120099.2024.2362296

The stabilities of uranyl-carbonate and uranyl-hydroxide aqueous complexes were experimentally determined at temperatures ranging from 25 to 125 °C using in situ UV–vis and Raman spectroscopic techniques. Combined with earlier determinations of the stability of chloride, sulfate, and hydroxide complexes at temperatures up to 250 °C, these data permit to create a consolidated dataset suitable for modeling of U(VI) mobilization in natural systems. The parameters of the Modified Ryzhenko-Bryzgalin and the Helgeson-Kirkham-Flowers (HKF) Equations of State (EoS) were derived based on this dataset and used for thermodynamic modeling different scenarios of U(VI) mobilization. These models suggest that at conditions relevant to natural systems, carbonate-mediated transport of U(VI) is likely suppressed by the high stability of solid UO2(OH)2 and Na2U2O7. In contrast, sulfate-mediated mobilization mechanisms are highly efficient at acidic and near-neutral pH conditions and can lead to effective hydrothermal mobilization of U(VI). <b>Citation:</b> A. Migdisov, E. Bastrakov, C. Alcorn, M. Reece, H. Boukhalfa, F.A. Capporuscio, C. Jove-Colon, A spectroscopic study of the stability of uranyl-carbonate complexes at 25–150 °C and re-visiting the data available for uranyl-chloride, uranyl-sulfate, and uranyl-hydroxide species, <i>Geochimica et Cosmochimica Acta</i>, 2024, ISSN 0016-7037, https://doi.org/10.1016/j.gca.2024.04.023.

The Exploring for the Future program Showcase 2024 was held on 13-16 August 2024. Day 4 - 16th August talks included: <b>Session 1 – Deep Dives into the Delamerian</b> <a href="https://youtu.be/09knAwPnD7s?si=acdu6pQgIj7DNlnj">Scaffold to success: An overview of the Delamerian Orogen, and its crustal and lithospheric architecture</a> - Chris Lewis <a href="https://youtu.be/5GQC5f5IkWc?si=rLPqxoZFkxGAEPEf">Only time will tell: Crustal development of the Delamerian Orogen in space and time</a> - David Mole <a href="https://youtu.be/PhdIYE49eqU?si=d7acyv5rbTW_wTiO">Is it a big deal? New mineral potential insights of the Delamerian Orogen</a> - Dr Yanbo Cheng <b>Session 2 – Deep dives into Birrindudu, West Musgrave and South Nicholson–Georgina regions</b> <a href="https://youtu.be/DEbkcgqwLE8?si=sBKGaMTq_mheURib">Northwest Northern Territory Seismic Survey: Resource studies and results</a> - Paul Henson <a href="https://youtu.be/k9vwBa1fM9E?si=VOG19nBC1DAk-jGH">Tracing Ancient Rivers: A hydrogeological investigation of the West Musgrave Region</a> - Joshua Lester <a href="https://youtu.be/Du1JANovz8M?si=1XEOF87gxhSP9UF3">Water's journey: Understanding groundwater dynamics in the South Nicholson and Georgina basins, NT and QLD </a>- Dr Prachi Dixon-Jain <b>Session 3 – Groundwater systems of the Curnamona and upper Darling-Baaka River</b> <a href="https://youtu.be/nU8dpekmEHQ?si=WygIzefKNzsU4gUA">Groundwater systems of the upper Darling-Baaka floodplain: An integrated assessment</a> - Dr Sarah Buckerfield <a href="https://youtu.be/AKOhuDEPxIA?si=ebradAT6EBwHhPQ_">Potential for a Managed Aquifer Recharge Scheme in the upper Darling-Baaka floodplain: Wilcannia region</a> - Dr Kok Piang Tan <a href="https://youtu.be/epUdD8ax2FQ?si=_aMO_e_ZDZESgLOR">Aquifer alchemy: Decoding mineral clues in the Curnamona region</a> - Ivan Schroder Exploring for the Future: Final reflection – Karol Czarnota Resourcing Australia’s Prosperity – Andrew Heap View or download the <a href="https://dx.doi.org/10.26186/149800">Exploring for the Future - An overview of Australia’s transformational geoscience program</a> publication. View or download the <a href="https://dx.doi.org/10.26186/149743">Exploring for the Future - Australia's transformational geoscience program</a> publication. You can access full session and Q&A recordings from YouTube here: 2024 Showcase Day 4 - Session 1 - <a href="https://www.youtube.com/watch?v=4nuIQsl71cY">Deep Dives into the Delamerian</a> 2024 Showcase Day 4 - Session 2 - <a href="https://www.youtube.com/watch?v=9N3dIZRAcHk">Deep dives into Birrindudu, West Musgrave and South Nicholson–Georgina regions</a> 2024 Showcase Day 4 - Session 3 - <a href="https://www.youtube.com/watch?v=_ddvLAnUdOI">Groundwater systems of the Curnamona and upper Darling-Baaka River</a>

<div>The footprint of a mineral system is potentially detectable at a range of scales and lithospheric depths, reflecting the size and distribution of its components. Magnetotellurics is one of a few techniques that can provide multiscale datasets to understand mineral systems. The Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) is a collaborative national survey that acquires long-period magnetotelluric data on a half-degree grid spacing (about 55 km) across Australia. This project aims to map the electrical conductivity/resistivity structure in the crust and mantle beneath the Australian continent. We have used AusLAMP as a first-order reconnaissance survey to resolve large-scale lithospheric architecture for mapping areas of mineral potential in Australia. AusLAMP results show a remarkable connection between conductive anomalies and giant mineral deposits in known highly endowed mineral provinces. Similar conductive features are mapped in greenfield areas where mineralisation has not been previously recognised. In these areas we can then undertake higher-resolution infill magnetotelluric surveys to refine the geometry of major structures, and to investigate if deep conductive structures are connected to the near surface by crustal-scale fluid-flow pathways.</div><div> We summarise the results from a 3D resistivity model derived from AusLAMP data in Northern Australia. This model reveals a broad conductivity anomaly in the lower crust and upper mantle that extends beneath an undercover exploration frontier between the producing Tennant Creek region and the prospective Murphy Province. This anomaly potentially represents a fertile source region for mineral systems. A subsequent higher-resolution infill magnetotelluric survey revealed two prominent conductors within the crust whose combined responses produced the lithospheric-scale conductivity anomaly mapped in the AusLAMP model. Integration of the conductivity structure with deep seismic reflection data revealed a favourable crustal architecture linking the lower, fertile source regions with potential depositional sites in the upper crust. Integration with other geophysical and geochronological datasets suggests high prospectivity for major mineral deposits in the vicinity of major faults.</div><div> This study demonstrates that the integration of geophysical data from multiscale surveys is an effective approach to scale reduction during mineral exploration in covered terranes.</div> This Abstract was submitted to and presented at the 6th International Archean Symposium Target 2023, 28 July (https://6ias.org/target2023/)

We collected 38 groundwater and two surface water samples in the semi-arid Lake Woods region of the Northern Territory to better understand the hydrogeochemistry of this system, which straddles the Wiso, Tennant Creek and Georgina geological regions. Lake Woods is presently a losing waterbody feeding the underlying groundwater system. The main aquifers comprise mainly carbonate (limestone and dolostone), siliciclastic (sandstone and siltstone) and evaporitic units. The water composition was determined in terms of bulk properties (pH, electrical conductivity, temperature, dissolved oxygen, redox potential), 40 major, minor and trace elements as well as six isotopes (δ18Owater, δ2Hwater, δ13CDIC, δ34SSO4=, δ18OSO4=, 87Sr/86Sr). The groundwater is recharged through infiltration in the catchment from monsoonal rainfall (annual average rainfall ~600 mm) and runoff. It evolves geochemically mainly through evapotranspiration and water–mineral interaction (dissolution of carbonates, silicates, and to a lesser extent sulfates). The two surface waters (one from the main creek feeding the lake, the other from the lake itself) are extraordinarily enriched in 18O and 2H isotopes (δ18O of +10.9 and +16.4 ‰ VSMOW, and δ2H of +41 and +93 ‰ VSMOW, respectively), which is interpreted to reflect evaporation during the dry season (annual average evaporation ~3000 mm) under low humidity conditions (annual average relative humidity ~40 %). This interpretation is supported by modelling results. The potassium (K) relative enrichment (K/Cl mass ratio over 50 times that of sea water) is similar to that observed in salt-lake systems worldwide that are prospective for potash resources. Potassium enrichment is believed to derive partly from dust during atmospheric transport/deposition, but mostly from weathering of K-silicates in the aquifer materials (and possibly underlying formations). Further studies of Australian salt-lake systems are required to reach evidence-based conclusions on their mineral potential for potash, lithium, boron and other low-temperature mineral system commodities such as uranium. <b>Citation:</b> P. de Caritat, E. N. Bastrakov, S. Jaireth, P. M. English, J. D. A. Clarke, T. P. Mernagh, A. S. Wygralak, H. E. Dulfer & J. Trafford (2019) Groundwater geochemistry, hydrogeology and potash mineral potential of the Lake Woods region, Northern Territory, Australia, <i>Australian Journal of Earth Sciences</i>, 66:3, 411-430, DOI: 10.1080/08120099.2018.1543208

To meet the rising global demand for base metals – driven primarily by the transition to cleaner-energy sources – declining rates of discovery of new deposits need to be countered by advances in exploration undercover. Here, we report that 85% of the world’s sediment-hosted base metals, including all giant deposits (>10 Mt of metal), occur within 200 km of the edge of thick lithosphere, irrespective of the age of mineralisation. This implies long-term craton edge stability, forcing a reconsideration of basin dynamics and the sediment-hosted mineral system. We find that the thermochemical structure of thick lithosphere results in increased basin subsidence rates during rifting, coupled with low geothermal gradients, which ensure favourable metal solubility and precipitation. Sediments in such basins generally contain all necessary lithofacies of the mineral system. These considerations allow establishment of the first-ever national prospectus for sediment-hosted base metal discovery. Conservative estimates place the undiscovered resource of sediment-hosted base metals in Australia to be ~50–200 Mt of metal. Importantly, this work suggests that ~15% of Australia is prospective for giant sediment-hosted deposits; we suggest that exploration efforts should be focused in this area. <b>Citation:</b> Czarnota, K., Hoggard, M.J., Richards, F.D., Teh, M., Huston, D.L., Jaques, A.L. and Ghelichkhan, S., 2020. Minerals on the edge: sediment-hosted base metal endowment above steps in lithospheric thickness. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

<div>Tin and tungsten have good potentials for increased demand applications particularly in the electrical and energy storage areas. Similar to other critical metals like Li and Co, Sn and W are essential ingredients for many applications and technologies that are important for a sustainable future. </div><div>&nbsp;</div><div>Granite related hydrothermal mineral systems are the predominant source for Sn and W deposits.Cassiterite, wolframite and scheelite are primary Sn and W ore minerals in nature. The distribution of Sn rich areas around the world is uneven, which may reflects that geochemical heritage is fundamental to form Sn and W deposits. Besides, magmatic differentiation has been considered as another efficient way to enrich Sn in various geological reservoirs. The tectonic setting of Sn and W mineralisation is well understood, with most Sn and W deposits having formed at active margin settings. A comparison between the Tethyan and Andean Sn-W mineral systems confirmed that Sn and W mineral systems can form under thickened continental crust associated with an oceanic crust subduction. The importance of granitoids for the formation of Sn and W mineral systems is well understood. The genetic affinity of causative intrusions can be either S-type, I-type or A-type, but a common feature is that they are reduced (or ilmenite series) and highly evolved (high SiO2 content and high Rb/Sr ratio). Another prominent feature for Sn and W mineral systems is their high concentration of critical metals, including Li, Ce, Ta and In etc. Therefore, Sn and W mineralisation has a close association with other critical metal mineralisation. Overall, the precipitation mechanisms of W (wolframite and scheelite) and Sn (cassiterite) ore minerals from the hydrothermal fluid include (1) fluids mixing, (2) boiling and, (3) water-rock interaction.&nbsp;</div><div><br></div><div>Recent studies have highlighted discrepancies in Sn mineralisation and W mineralisation conditions. Although Sn- and W-associated granites have substantial overlapping characteristics, many of their physico-chemical natures (e.g., aluminum-saturation index (ASI) values, zirconium saturation temperatures and crystal fractionation degrees) are distinctive, suggesting Sn- and W-granites may form under different geological conditions. The difference between Sn mineralisation and W mineralisation is also evident by their contrasting fluid-melt partitioning coefficients. Tungsten strongly partitions into the aqueous fluid and can be transported farther away from the intrusion, but Sn slightly partitions into the silicate melt and can precipitate as magmatic cassiterite or be incorporated into crystallizing micas (which can have >100 ppm Sn). Another area warranting more study is understanding the elemental associations observed in Sn and W mineral systems. It is common to have many other metals in Sn-dominant mineral systems, for example W, Li, Nb, Ta. For W-dominant mineral systems, apart from with Sn, other common associated metals include Mo, Au-Bi and Cu. Nevertheless, the relationship between Sn-W and Cu-Au mineral systems at both the regional/provincial-scale and deposit-scale is an intriguing puzzle, because Sn-W and Cu-Au deposits are generally formed under different geological conditions, though their tectonic setting are similar, i.e., arc-related subduction and continental collision. An emerging field for understanding Sn and W mineral systems is made possible with the development of micro-analytical techniques, e.g., in-situ U-Pb geochronology and O-isotopic analyses on cassiterite and wolframite enable a greater understanding of Sn and W mineralising systems. Since both are the primary ore minerals, U-Pb dating on them can deliver direct age information - an advantage compared with many other commodities types like Cu, Au and Ag. However, unlike those commodities, impactful advances on Sn and W exploration models, techniques, and tools have been deficient in recent years; therefore, more attention and effort is needed to boost Sn and W mineral exploration in the future.</div><div><br></div>This paper was presented to the 2022 Asian Current Research on Fluid Inclusions IX (ACROFI IX) Conference 12-13 December (http://www.csmpg.org.cn/tzgg2017/202210/t20221011_6522628.html)

<div>Maps showing the potential for iron oxide copper-gold (IOCG) mineral systems in Australia. Each of the mineral potential maps is a synthesis of four component layers (source of metals, fluids and ligands; energy sources and fluid flow drivers; fluid flow pathways and architecture; and ore depositional gradients). The model uses a hybrid data-driven and knowledge driven methodology to produce the final mineral potential map for the mineral system. An uncertainty map is provided in conjunction with the mineral potential maps that represents the availability of data coverage over Australia for the selected combination of input maps. Uncertainty values range between 0 and 1, with higher uncertainty values being located in areas where more input maps are missing data or have unknown values. The input maps and mineral deposits and occurrences used to generate the mineral potential map are provided along with an assessment criteria table which contains information on the map creation.</div>

<div><strong>Output type:</strong> Exploring for the Future Extended Abstract</div><div><br></div><div><strong>Short abstract: </strong>Iron oxide copper-gold (IOCG) deposits are a significant source of copper and gold and can also contain critical minerals that are required for the transition to a low carbon economy and to increase Australia’s security of mineral supply. Given their strategic importance, a national-scale assessment of the mineral potential for IOCG mineral systems in Australia has been undertaken using a hybrid data- and knowledge-driven approach. The national-scale assessment includes the evaluation of the statistical importance of mappable criteria used in previously published regional-scale IOCG models, resulting in the removal of five criteria and the inclusion of four new or revised criteria derived from datasets developed through the Exploring for the Future program. The new mineral potential model successfully predicts the location of 91.7% of known IOCG deposits and occurrences in 8.3% of the area, reducing the exploration search space by 91.7% and highlighting new areas of elevated prospectivity in under-explored regions of Australia. When compared to existing regional-scale mineral potential assessments for IOCG mineral systems published by Geoscience Australia, the new national-scale model demonstrates higher prospectivity in areas with known IOCG deposits and occurrences, while also highlighting new prospective areas for IOCG mineral systems. Areas with assessed high prospectivity but lacking known IOCG mineralisation include parts of the Curnamona, Etheridge and Musgrave provinces, and the Delamerian, Halls Creek and Tanami orogens.</div> <div><strong>Citation</strong>: Cloutier J., et al., 2024. First national mineral system assessment of Australia's iron oxide copper-gold potential. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://doi.org/10.26186/149357</div>

<div>As part of the Delamerian Margins NSW National Drilling Initiative campaign, seventeen stratigraphic boreholes were drilled between Broken Hill and Wentworth, in Western NSW. These holes were designed to test stratigraphic, structural, and mineral systems questions in the New South Wales portion of the Delamerian Margin. Drilling was conducted between March and June 2023 and was undertaken by Geoscience Australia in collaboration with MinEx CRC. This report outlines basic borehole targeting rationale, borehole metadata, and analyses performed immediately following drilling to accompany data available through the Geoscience Australia portal.</div><div><br></div><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. This leads to a strong economy, resilient society and sustainable environment for the benefit of all Australians. This includes supporting Australia’s transition to net zero emissions, strong, sustainable resources and agriculture sectors, and economic opportunities and social benefits for Australia’s regional and remote communities. The Exploring for the Future program, which commenced in 2016, is an eight year, $225m investment by the Australian Government.</div>