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 Neoproterozoic to Middle Ordovician sediments of the Officer Basin, Australia are difficult to correlate, in part because biostratigraphic studies of acritarchs and stromatolites are localised, isotopic studies are rare, and seismic models are technically challenged by the occurrence of basaltic and halite prone-sections. Hence, the chemostratigraphic framework presented here provides an independent stratigraphic model for the Neoproterozoic to Middle Ordovician sediments of the Officer Basin. A total of six chemostratigraphic mega-sequences have been geochemically defined and assigned to the stratigraphy; these have been further subdivided into twenty-eight chemostratigraphic sequences. The chemostratigraphic zonation has been established upon elemental changes attributed to provenance and climatic variation which can be used for correlation as they convey regional, rather than local, changes in sedimentation. The elemental data reveals that there is lateral variation within the established lithostratigraphy (e.g., within the members of the Observatory Hill and Hussar formations), which is suggestive of localised sediment source input to different areas of the basin. Presented to the 2022 Central Australian Basins Symposium IV (CABS) 29-30 August (https://agentur.eventsair.com/cabsiv/)

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.

This report presents the results of chemostratigraphic analyses for samples of the Waukarlycarly 1 deep stratigraphic well drilled in in the Waukarlycarly Embayment of the Canning Basin. The drilling of the well was funded by Geoscience Australia’s Exploring for the Future initiative to improve the understanding of the sub-surface geology of this underexplored region of the southern Canning Basin. The well was drilled in partnership with Geological Survey of Western Australia (GSWA) as project operator. Waukarlycarly 1 reached a total depth (TD) of 2680.53 m at the end of November 2019 and was continuously cored from 580 mRT to TD. The work presented in this report constitutes part of the post-well data acquisition. An elemental and isotope chemostratigraphic study was carried out on 100 samples of the well to enable stratigraphic correlations to be made across the Canning Basin within the Ordovician section known to host source rocks. Nine chemostratigraphically distinct sedimentary packages are identified in the Waukarlycarly 1 well and five major chemical boundaries that may relate to unconformities, hiatal surfaces or sediment provenance changes are identified. The Ordovician sections in Waukarlycarly 1 have different chemical signals in comparison to those in other regional wells, suggestive of a different provenance for the origin of the sediments in the Waukarlycarly Embayment compared to the Kidson Sub-basin (Nicolay 1) and Broome Platform (Olympic 1).

<div>Quality assurance and quality control (QAQC) of geochemical data is an important first step before any interpretation of the data is undertaken. Due to the increasing number of elements that are being reported by laboratories undertaking multi-element analysis, the time to undertake QAQC of the data has increased. In order to alleviate the increasing time constraints of undertaking QAQC this python script was developed. This script provides a quick first pass of the data automatically to produce summary statistics and plots of the included standards laboratory duplicates and analytical duplicates. The statistics and plots allow for rapid assessment of geochemical data to discover potential issues with the data and trends though time, whilst also providing a consistent approach. It should be noted that no general quality cut-offs have been included within the script as it does not replace the need for an expert examining the data to identify potential issues.</div>

<div>As part of Geoscience Australia’s Exploring for the Future program, the Curnamona Geochemistry project is producing a comprehensive compilation of geochemical data from the Broken Hill region, encompassing rock, regolith and groundwater. As part of these efforts, geochemical data has been compiled, cleaned and standardised to enable more seamless interpretation and exploration of geochemical anomalies. This project improves the quality, accessibility and volume of geochemical data across the Curnamona region and supports our ongoing efforts to define regional geochemical baselines.</div> This presentation was given to the 2022 Geological Survey of South Australia (GSSA) Discovery Day 1 December (https://www.energymining.sa.gov.au/home/events-and-initiatives/discovery-day)

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>The Exploring for the Future (EFTF) program is an Australian government initiative aimed at stimulating investment in resource exploration and development. It operates multiple interconnected projects, such as the Australia’s Resources Framework (ARF), a continental-scale endeavor to enhance understanding of Australia's geology and resource potential. A module of ARF, the Geochemistry for Basin Prospectivity (G4BP), studies Australian basins with prospective base metal mineral systems. </div><div><br></div><div>The current report focuses on the Neoproterozoic segment of the Stuart Shelf region in South Australia, a part of the Adelaide Rift Complex. This research is conducted collaboratively with the Geological Survey of South Australia, examining sediment-hosted copper potential in the rift complex.</div><div><br></div><div>The Adelaide Rift Complex is a geological formation that underwent extensive sedimentation from the Neoproterozoic to early Cambrian, particularly within the rift zone. Stuart Shelf sediments overlay Mesoproterozoic magmatic and Paleoproterozoic metasediment layers. The complex hosts multiple copper deposits, which are usually associated with movement of basinal brines that leach metals from lower basinal layers or rift-related volcanic rocks.</div><div><br></div><div>To improve understanding of the geology of the Stuart Shelf and related copper mineralisation, two primary objectives were set: </div><div><br></div><div>1. Geochemical fingerprinting and baseline data collection: This involves compilation and reanalysis of existing data, along with new data collection aimed at providing comprehensive geochemical data for stratigraphic units within the Stuart Shelf.</div><div><br></div><div>2. Identification of mineral system components: Utilising data from the first objective, this phase aims to identify potential metal and fluid sources and potential sites of metal deposition. </div><div>In conjunction with these efforts, a GA-GSSA geochemical sampling project is underway, tying geochemistry to lithostratigraphic units and facies. The newly acquired geochemical data will be integrated into the overall GSSA-CSIRO project to contribute to a more comprehensive understanding of the sediment-hosted stratabound mineral system.</div><div><br></div>

Paleoproterozoic arc and backarc assemblages accreted to the south Laurentian margin between 1800 Ma and 1600 Ma, and previously thought to be indigenous to North America, more likely represent fragments of a dismembered marginal sea developed outboard of the formerly opposing Australian-Antarctic plate. Fugitive elements of this arc-backarc system in North America share a common geological record with their left-behind Australia-Antarctic counterparts, including discrete peaks in tectonic and/or magmatic activity at 1780 Ma, 1760 Ma, 1740 Ma, 1710-1705 Ma, 1690-1670 Ma, 1650 Ma and 1620 Ma. Subduction rollback, ocean basin closure and the arrival of Laurentia at the Australian-Antarctic convergent margin first led to arc-continent collision at 1650-1640 Ma and then continent-continent collision by 1620 Ma as the last vestiges of the backarc basin collapsed. Collision induced obduction and transfer of the arc and more outboard parts of the Australian-Antarctic backarc basin onto the Laurentian margin where they remained following later breakup of the Neoproterozoic Rodinia supercontinent. North American felsic rocks generally yield Nd depleted mantle model ages consistent with arc and backarc assemblages built on early Paleoproterozoic Australian crust as opposed to older Archean basement making up the now underlying Wyoming and Superior cratons. Appeared in Lithosphere (2019) 11 (4): 551–559, June 10, 2019.

<div>Geoscience Australia has a large holding of surface sediment samples, such as stream and overbank sediments, from geochemical surveys conducted over more than 50 years across the Australian continent. Geochemical data from these surface materials are of national importance as they can contribute significantly to establishing geochemical environmental baselines and their use in land management, as well as aiding in the discovery of new mineral deposits. Samples from these legacy surveys provide valuable insights into areas of Australia that are remote, difficult to access, or have since been developed. The age of a large number of these surveys, however, means that the original results included data for a&nbsp;smaller range of chemical elements, typically with poorer analytical precision and accuracy than those of modern surveys. This small range of chemical elements also typically doesn’t include important elements for modern use, such as critical minerals (i.e. Co, Bi, REEs), which are increasing in their importance. As part of Geoscience Australia’s Exploring for the Future program, a collection of over 9000 samples from these surveys was reanalysed using modern analytical techniques for a&nbsp;suite of 60 chemical elements. These samples cover several regions within Australia, including Kakadu, Cape York, the Mount Isa region, and near the Canberra region. The new analytical data maximise the value of the historical geochemical surveys and will provide new insights into the mineral potential of these regions and improve the quality of geochemical environmental baselines.&nbsp;</div><div><br></div><div>This data release includes: 1) information on the surveys and their samples; 2) quality assurance results; 3) a discussion of sample preparation and analytical methods used; 4) results for total content geochemistry (XRF and LA-ICP-MS); and 5) individual element maps for each of the regions for preliminary interpretation of the data.</div><div><br></div><div>Acquisition and release of this dataset forms part of a larger program aimed at creating a levelled geochemical baseline for the whole Australia (Main and Champion, 2020).</div>