Carbon Capture and Storage (CCS) is a technique for mitigating anthropogenic climate change by separating CO2 from industrial flue gas, transporting it to and storing it in a subsurface geological storage reservoir. The low-salinity (TDS<3 000 mg/L) Jurassic sandstone formations in Australia's Surat Basin have been identified as a potential reservoir system for geological CO2 sequestration. However, given the prevailing use of saline reservoirs in CCS projects elsewhere, limited data are available on CO2-water-rock dynamics during geological sequestration in such low-salinity formations. Here, a combined batch experiment and numerical modelling approach is used to characterise potential CO2-water-rock reaction pathways, to assess potential impacts of CCS on groundwater chemistry, and to identify geochemical tracers of inter- and intra-formational CO2 migration during geological sequestration within the Jurassic sandstones. Mineralogy and physical properties of the prospective reservoir are characterized for 66 core samples from stratigraphic well GSQ Chinchilla 4. Representative samples are reacted with synthetic formation water and high-purity CO2 for up to 27 days at a range of pressures to simulate conditions during carbon sequestration in the Jurassic sandstones. Results show the low formation water salinity, temperature, and mineralization in the reservoirs yield high solubility trapping capacity (1.18 mol/L at 45°C, 100 bar), while the paucity of divalent cations in groundwater and the silicate reservoir matrix result in very low mineral trapping capacity within the footprint of the supercritical CO2 (scCO2) plume. Though alkalinity buffers formation water pH under elevated CO2 pressure, the acidic pH significantly enhances mineral dissolution in reactors with heterogeneous Hutton and Boxvale Sandstone samples. Smaller TDS changes are observed for samples of the mature Precipice Sandstone than for the other formations. Non-radiogenic, regional groundwater-like 87Sr/86Sr values (0.704845 - 0.706600) in batch reactors indicate carbonate and authigenic clay dissolution as the primary reaction pathways regulating solution composition in all formations during carbon sequestration. Slightly higher Sr isotope ratios in felsic samples than in calcitic samples, and dissolved Si concentrations in mature Precipice Sandstone reactors show detrital silicate dissolution to be an ancillary process. Batch reactor degassing at the end of the incubation period was simulated to assess geochemical changes in formation waters during transport away from a scCO2 plume. Model results suggest geological sequestration in the Jurassic sandstone formations would increase regional groundwater alkalinity and redistribute carbonate minerals outside the scCO2 footprint, but is unlikely to result in net mineral trapping of CO2. Several elements are mobilised in concentrations greater than found in regional groundwater, making them viable tracers of CO2 migration. Most notable is cobalt, concentrations of which are significantly elevated regardless of CO2 pressure or sample mineralogy. Experimental results indicate manganese and cadmium concentrations may locally exceed drinking water quality guidelines, but further modelling of intra aquifer mixing is required to quantify the potential risk to regional groundwaters from trace element mobilisation.

<div>A groundwater chemistry, regolith chemistry and metadata record for legacy geochemical studies over the southern Curnamona Province done by GA and partners as part of CRC LEME from 1999 to 2005, that was never fully released. This includes comprehensive groundwater chemistry from more than 250 bores in the Broken Hill region, containing physicochemical parameters, major and trace elements, and a suite of isotopes (34S, Pb, Sr, 18O, D). Recent work on this dataset (in 2021) has added hydrostratigraphic information for these groundwater samples. Also included is a regolith geochemistry dataset collected adjacent to some of the groundwater bores which tests the geochemical response of a range of different size fractions, depths and digests.</div>

The Exploring for the Future (EFTF) program is an Australian government initiative to boost investment in resource exploration and development in Australia, and is committed to supporting a strong economy, resilient society and sustainable environment for the benefit of Australians. There are a number of interrelated projects within the EFTF, including the Australia’s Resources Framework (ARF) project. The latter is a continental-scale project aimed at laying the foundations for a national view of Australia’s surface and subsurface geology, to underpin our understanding of the continent’s mineral, energy and groundwater potential. The ARF project involves new, large-scale data acquisition, advances in big data analytics and tailored resource assessments, to support the resource sector, agriculture, remote communities and the environment, and contribute to community safety. As part of ARF, Geoscience Australia has been undertaking studies of Australian basins that are prospective for, or have potential for, basin-hosted base metal mineral systems (Pb-Zn, Co-Cu), as part of the basins module. The first component of this module (2016-2020) investigated the Paleoproterozoic to Mesoproterozoic greater McArthur Basin system, Northern Territory and western Queensland (Champion et al., 2020 a, b, c; Huston et al. 2020). The 2020-2024 module is focusing on the Neoproterozoic part of the Stuart Shelf region of the Adelaide Superbasin, South Australia. The Paleo- to Mesoproterozoic sedimentary and volcanic sequences of the Mount Isa–McArthur Basin region of Northern Territory and Queensland are host to a range of world class mineral deposits (Hutton et al., 2012) and include the basin-hosted base metal deposits of the North Australian Zinc Belt, the world’s richest belt of zinc deposits (Huston et al., 2006; Large et al., 2005). These syngenetic (and epigenetic) basin-hosted mineral deposits include McArthur River (formerly HYC) and Century lead-zinc (Pb-Zn) deposits, the Walford Creek Zn-Pb-Cu-Ag deposit (Rohrlach et al., 1998; Large et al., 2005; Hutton et al. 2012) and the Redbank Cu deposit (Knutson et al. 1979). The Neoproterozoic sedimentary sequences of the Stuart Shelf, and their continuation into the Torrens Hinge Zone and Adelaide Rift Complex (Adelaide Superbasin), South Australia, are host to, or form an integral part of, a number of, often historically important, deposits, including the first copper mining region in Australia. These include, amongst others, the Kapunda, Mt Gunson, Cattle Grid, MG14, Windabout, Myall Creek, and Emmie Bluff copper deposits (Lambert et al. 1980, 1984, 1985 1987; Knutson et al. 1983; Coda Minerals 2020, 2021). These deposits are hosted within the Neoproterozoic sediments or along the basal unconformity with older Mesoproterozoic clastic sedimentary rocks (Lambert et al. 1987). This report contains reanalysed geochemical data, and associated sample metadata, for legacy samples collected by the Baas Becking laboratories in the 1970’s from deposits and surrounds in the MacArthur Basin and Stuart Shelf region. This includes samples (mafic igneous rocks, mineralised samples and sedimentary rocks) from the Redbank Cu deposit and surrounds in the McArthur Basin, partly documented in Knutson et al. (1979); samples (sediments, mafic igneous rocks including basement volcanic units (Gawler Range Volcanics), and mineralised samples) from the Mt Gunson deposit and surrounds (Mt Gunson-Lake Dutton area) documented in Knutson et al. (1983, 1992); and a small subset of five samples (sediments, variably mineralised) from the Myall Creek prospect, documented in Lambert et al. (1984). The great majority of these samples are from drill core, with the full list of samples analyses and metadata listed in Appendix A and summarised in Table 1. This data release also includes 52 samples from the Killi Killi Hills regions and surrounds, Tanami, Northern Territory (jobno 9004424), collected by the NTGS and GA, and originally analysed, in the early 1990’s and early 2000’s. These samples included a subset of P2O5-Sr-HREE-enriched Gardiner Sandstone samples from the Killi Killi Hills prospect. These samples are not directly related to the basins project but have been included as they were analysed at the same time as the Stuart Shelf and Redbank samples, and they increase the number of samples and the range of rock types analysed, and so help with statistics for QA/QC purposes. All geochemical data are provided in the appendices, listed by batch. The data can be downloaded via the Geoscience Australia EFTF portal (https://portal.ga.gov.au/persona/eftf).

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.

<div>Heavy rare earth elements are essential in renewable energy and high-tech products. Some natural rare earth element (REE) deposits exhibit heavy rare earth element (HREE) enrichment from &lt;&nbsp;10% to ~85% of the REE budget (Williams-Jones et al., 2015). </div><div><br></div><div>Controls on REE fractionation in hydrothermal systems are imposed by (1) changes in the relative stability of REE aqueous complexes with temperature (Migdisov et al., 2016) and (2) incorporation or rejection of REE by crystalline structures. Also, the REEs are invariably found as solid solutions but not as pure minerals. REE and yttrium (Y) sulphate complexes are some of the most stable REE and Y aqueous species in hydrothermal fluids (Migdisov and William-Jones, 2008, 2016; Guan et al., 2022) and may be responsible for REE transport and deposition in sediment-hosted deposits. Within the unconformity-related deposits, REEs are hosted mostly by xenotime ((Y,Dy,Er,Tb,Yb)PO4) and minor florencite ((La,Ce)Al3(PO4)2(OH)6) (Nazari-Dehkordi et al., 2019). Modelling the stability of xenotime in the H-O-Cl-(±F)-S-P aqueous system is critical for understanding HREE enrichment in this mineral system.</div><div><br></div><div>We use a newly derived thermodynamic dataset depos for REESO4+ and REE(SO4)2‑ aqueous complexes to generate stability diagrams illustrating mechanisms of REE transport and deposition in the above deposits. Sulphate REE complexes may dominate even in chloride-rich brines and facilitate REE mobilization in acid oxidizing environments. Previously Nazari-Dehkordi et al. (2019) proposed an ore genesis model involving the mixing of discrete hydrothermal fluids that separately carried REE + yttrium and phosphorus. The speciation model that includes sulphate complexes expands this scenario; a process resulting in fluid neutralization or reduction will also promote precipitation of xenotime enriched in HREEs.&nbsp;</div><div><br></div>This Abstract was submitted/presented to the 2022 Specialist Group in Geochemistry, Mineralogy and Petrology (SGGMP) Conference 7-11 November (https://gsasggmp.wixsite.com/home/biennial-conference-2021)

This report presents the results of an elemental and carbon and oxygen isotope chemostratigraphy study on three historic wells; Kidson-1, Willara-1 and Samphire Marsh-1, from the southern Canning Basin, Western Australia. The objective of this study was to correlate the Early to Middle Ordovician sections of the three wells to each other and to wells with existing elemental and carbonate carbon isotope chemostratigraphy data from the Broome Platform, Kidson and Willara sub-basins, and the recently drilled and fully cored stratigraphic Waukarlycarly 1 well from the Waukarlycarly Embayment.

<div>Levelling of geochemical data between surveys is a vital step in using datasets together. This code can apply a number of approaches to eliminate inter-laboratory differences from multi-generational and spatially isolated geochemical surveys. This codes allow the use of a variety of levelling methods: re-analysis, single standards, and multiple standards. The methodology and effectiveness of each of these methods are outlined in Main, P.T. and Champion, D.C., 2022. Levelling of multi-generational and spatially isolated geochemical surveys. Journal of Geochemical Exploration.</div>

<div>The lithology, geochemistry, and architecture of the continental lithospheric mantle (CLM) underlying the Kimberley Craton of north-western Australia has been constrained using pressure-temperature estimates and mineral compositions for &gt;5,000 newly analyzed and published garnet and chrome (Cr) diopside mantle xenocrysts from 25 kimberlites and lamproites of Mesoproterozoic to Miocene age. Single-grain Cr diopside paleogeotherms define lithospheric thicknesses of 200–250 km and fall along conductive geotherms corresponding to a surface heat flow of 37–40 mW/m 2. Similar geotherms derived from Miocene and Mesoproterozoic intrusions indicate that the lithospheric architecture and thermal state of the CLM has remained stable since at least 1,000 Ma. The chemistry of xenocrysts defines a layered lithosphere with lithological and geochemical domains in the shallow (&lt;100 km) and deep (&gt;150 km) CLM, separated by a diopside-depleted and seismically slow mid-lithosphere discontinuity (100–150 km). The shallow CLM is comprised of Cr diopsides derived from depleted garnet-poor and spinel-bearing lherzolite that has been weakly metasomatized. This layer may represent an early (Meso to Neoarchean?) nucleus of the craton. The deep CLM is comprised of high Cr2O3 garnet lherzolite with lesser harzburgite, and eclogite. The peridotite components are inferred to have formed as residues of polybaric partial mantle melting in the Archean, whereas eclogite likely represents former oceanic crust accreted during Paleoproterozoic subduction. This deep CLM was metasomatized by H2O-rich melts derived from subducted sediments and high-temperature FeO-TiO2 melts from the asthenosphere.</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><div><br></div><div><strong>Citation:</strong></div><div>Sudholz, Z.J., et al. (2023) Mapping the Structure and Metasomatic Enrichment of the Lithospheric Mantle Beneath the Kimberley Craton, Western Australia,&nbsp;<em><i>Geochemistry, Geophysics, Geosystems</i>,</em>&nbsp;24, e2023GC011040.</div><div>https://doi.org/10.1029/2023GC011040</div>

A comprehensive geochemical program was carried out on rock samples collected in the NDI Carrara 1 drill hole, the first stratigraphic test of the newly discovered Carrara Sub-basin located in the South Nicholson region of northern Australia. The drill hole recovered continuous core from 284 m to total depth at 1750 m and intersected approximately 1120 m of Proterozoic sedimentary rocks, unconformably overlain by 630 m of Cambrian Georgina Basin carbonate-rich rocks. Total organic carbon (TOC) contents from Rock-Eval pyrolysis highlight the potential for several thick black shales to be a source of petroleum for conventional and unconventional plays. Cambrian rocks contain an organic-rich section with TOC contents of up to 4.7 wt.% and excellent oil-generating potential. The Proterozoic section is overmature for oil generation but mature for gas generation, with potential for generating gas in carbonaceous mudstones showing TOC contents up to 5.5 wt.% between 680 and 725 m depth. A sustained release of methane (up to 2%) recorded during drilling from 1150 to 1500 m suggests potential for an unconventional gas system in the Proterozoic rocks from 950 to 1415 m depth, which exhibit favourable organic richness and thermal maturity. The Proterozoic rocks, which are comparable in age to the sediment-hosted deposits of the Century Mine, contain local occurrences of lead, zinc and copper sulfide minerals providing hints of mineralisation. The combined geochemical results offer the promise of a potential new resource province in northern Australia. <b>Citation:</b> E. Grosjean, A.J.M. Jarrett, C.J. Boreham, L. Wang, L. Johnson, J.M. Hope, P. Ranasinghe, J.J. Brocks, A.H.E. Bailey, G.A. Butcher, C.J. Carson, Resource potential of the Proterozoic–Paleozoic Carrara depocentre, South Nicholson region, Australia: Insights from stratigraphic drilling, <i>Organic Geochemistry</i>, Volume 186, 2023, 104688, ISSN 0146-6380, DOI: https://doi.org/10.1016/j.orggeochem.2023.104688.

<b>Legacy service retired 29/11/2022</b> This is an Open Geospatial Consortium (OGC) web service providing access to Australian onshore and offshore borehole data conforming to the GeoSciML version 4.0 specification. The borehole data includes Mineral Drillholes, Petroleum Wells and Water Bores along with a variety of others types. The dataset has been restricted to onshore and offshore Australian boreholes, and bores that have the potential to support geological investigations and assessment of a variety of resources.