Communities and ecosystems along the Darling River face critical water shortages and water quality issues including high salinity and algal blooms due to a reliance on declining surface water flows, which are impacted by extraction and drought, exacerbated by increases in temperature driven by climate change. The Darling River, characterised by highly variable flows, is the primary water source for the region and our understanding of the spatial extent and character of lower salinity groundwater within the surrounding Darling Alluvium, which could provide an alternative water source, is limited. Scientific understanding of the highly variable groundwater-surface water system dynamics of the Darling River is also an integral part of the evidence base required to manage the water resources of the wider Murray-Darling Basin, which has experienced critical water shortages for domestic and agricultural consumptive use and serious ecological decline due to reduced flows. Other relevant groundwater systems in the study area include aquifers of the underlying Eromanga and Surat Basins in the north, aquifers of the Murray Basin in the south, and fractured rock aquifers of the Darling Basin in the south-central area. Understanding of connectivity between these systems and the groundwater systems within the Darling Alluvium, and surface water of the Darling River, is also limited. Here we present the findings of a desktop analysis combining previous research with new analysis on water level, hydrochemistry, and Airborne Electromagnetic depth sections. This integration suggests that basement geometry and hydrostratigraphy within the Darling Alluvium are key structural controls on surface-groundwater connectivity, and the occurrence of a saline groundwater system within the lower part of the alluvium which impacts the quality of surface water and shallow alluvial groundwater resources. Further data acquisition and integrated analysis are planned to test these relationships as part of the Upper Darling Floodplain project. <b>Citation:</b> Buckerfield S., McPherson A., Tan K. P., Kilgour P. & Buchanan S., 2022. From Upper Darling Floodplain groundwater resource assessment. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://dx.doi.org/10.26186/146847

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.

<div>The Curnamona Province and overlying basins (herein referred to as the Broken Hill region) contain many discrete groundwater systems. These include sedimentary aquifers of the Lake Eyre Basin, Eromanga Basin, Darling Basin and Arrowie Basin, as well as fractured rock aquifers of the Adelaide Superbasin and Curnamona Province. However, there is little known about the hydrogeology or hydrogeochemistry of these aquifers in the Broken Hill region. Given the semi-arid climate in this region, understanding these groundwater systems can better support sustainable use of the groundwater for agriculture, mining and potable water supplies.</div><div>&nbsp;</div><div>Aquifer attribution provides a fundamental starting point for any hydrogeological study. We will present recently released hydrogeochemical data for the Broken Hill region, and our subsequent process for assessing and attributing hydrostratigraphy to the samples. </div><div>The Broken Hill Groundwater Geochemistry dataset (BHGG) was recently released in its entirety (Caritat et al. 2022 http://dx.doi.org/10.11636/Record.2022.020). It contains a compilation of archival CRC LEME hydrochemistry data that was collected as part of several projects from 1999 to 2005. This high-quality dataset contains 275 groundwater samples and includes a comprehensive suite of majors, minors, trace elements and stable isotopes (δ34S, δ18O, δ2H, δ13C, 87Sr/86Sr, 208/207/206Pb/204Pb). </div><div> At the time of collection, some key bore metadata (e.g. bore depths, screen and aquifer information) were missing from the original data compilations and these metadata are crucial for any hydrogeological analysis and interpretation. Therefore, as part of the new BHGG data release we have developed a robust and consistent approach to add bore information and aquifer attribution, value-adding to the original BHGG chemical and isotopic data. This workflow utilises a combination of State databases, reports, field notes, drillhole compilations and geological maps, but still relied on local hydrological expertise to make decisions when encountering incomplete or conflicting information (which is reflected by a confidence rating on the attribution). </div><div> The resulting BHGG product has supported re-assessment of the key hydrogeological and geochemical knowledge gaps in each groundwater system. An overview of knowledge gaps and the new sampling program being undertaken will be included in the presentation. &nbsp;</div><div><br></div>This Abstract was submitted/presented to the 2022 Australasian Groundwater Conference 21-23 November (https://agc2022.com.au/)

<div>A keynote talk talk given at Uncover Curnamona 2022 by Angela O'Rourke outlining the rationale, work program and new data acquisition for Geoscience Australia's Darling-Curnamona-Delamerian Project within Exploring for the Future</div> This presentation was given to the 2022 Uncover Curnamona 2022 Conference 31 May - 2 June:<br>(https://www.gsa.org.au/common/Uploaded%20files/Events/Uncover%20Curnamona%202021/UC2022_short_program_A4_web%20(003).pdf)

<div>In June to September 2022 an airborne electromagnetic (AEM) survey was flown over parts of the Curnamona Province, Delamerian Orogen and Darling Region in South Australia, New South Wales and Victoria.&nbsp;Geoscience Australia commissioned the survey in collaboration with the Department of Regional New South Wales as part of the Australian Government’s Exploring for the Future program. A total of 14,509 line kilometres of new data were acquired, of which 3,407 line kilometres were funded by the Department of Regional New South Wales. GA managed all aspects of the acquisition, quality control and processing of the AEM data.</div><div><br></div><div>The survey was flown by Skytem Australia Pty Ltd using its SkyTEM312Fast AEM system. The survey was conducted on east-west lines spaced at 2,500 m and 5,000 m apart.&nbsp;Skytem Australia Pty Ltd also processed the data. This data package includes the acquisition and processing report, the final processed AEM data and the results of the 1D laterally constrained inversion of the data to conductivity-depth estimates that was carried out by the contractor. The data package additionally contains the results and derived products from a 1D inversion carried out by Geoscience Australia with its own inversion software.</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 a low emissions economy, strong 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>This study is part of the Mineral Potential Assessment (MPA) module of Geoscience Australia's Darling-Curnamona-Delamerian (DCD) project, a deep-dive project within the Exploring for the Future Program (EFTF) 2020-2024. An objective of the DCD project is to further the understanding of the geological architecture of the Delamerian Orogen into a cohesive framework enable a regional mineral potential assessment of this under-explored and mostly under cover Orogen. The MPA module is one of eight modules under the umbrella of the DCD project. To facilitate assessment of the mineral potential of the project area, the mineral potential assessment study has 3 key scientific objectives: (1) Defining the characteristics of the mineral systems / prospects. (2)&nbsp;&nbsp;Evaluating the temporal framework of the formation of mineral systems / prospects; and (3) Understanding the regional magma fertility. This study delivers Objective 1, i.e., outlining the principle geological and metallogenic characteristics of reported mineral prospects in the project area.&nbsp;</div><div><br></div><div>Legacy drill cores best demonstrating metallogenic features of different mineral system types at key prospects across the project area were selected for viewing and sampling following review of historical exploration reports and assay results. Four sets of data are included in the appendices of this report: (1)&nbsp;&nbsp;HyLogger spectral images of 20 drill holes of 8 prospects in New South Wales. (2)&nbsp;&nbsp;143 high-resolution scan files of legacy drill core samples across the project area. (3)&nbsp;&nbsp;16 microscopic images of thin sections for 4 prospects of the Loch Lilly-Kars Belt, New South Wales. (4)&nbsp;&nbsp;53 Backscattered Electron (BSE) images and 53 Advanced Mineral Identification and Characterization System (AMICS) high-resolution mineral maps of 53 samples from 18 prospects across the whole Delamerian Margin.&nbsp;</div><div><br></div><div>Metallogenic characteristics of samples from four different mineral deposit types were studied, along deposits of uncertain affiliation (referred here as undefined systems), including (1) Porphyry-epithermal mineral systems. (2)&nbsp;&nbsp;Volcanic hosted massive sulfide (VHMS) mineral systems. (3)&nbsp;&nbsp;Orogenic gold mineral systems. (4)&nbsp;&nbsp;Mafic-ultramafic Cu-Ni-PGE mineral systems. (5)&nbsp;&nbsp;Metallogenetically undefined systems. Detailed metallogenic characteristics of the samples from 22 key prospects in Delamerian Orogen are documented in this report.&nbsp;&nbsp;</div><div><br></div><div>This is the first systemic study on the essential metallogenic characteristics of the mineral systems in Delamerian. The characterisations outlined in this report are foundational for understanding the regional metallogenesis and assessing the potential of multiple types of mineral systems in the Delamerian Belt, which should be useful in both academic and the mineral exploration sector.</div><div><br></div><div>The high-resolution BSE and AMICS mineral maps are available at Geoscience Australia. Please reach out to the senior author of this GA Record, Dr. Yanbo Cheng (Yanbo.cheng@ga.gov.au). </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. This work contributes to building a better understanding of the Australian continent, whilst giving the Australian public the tools they need to help them make informed decisions in their areas of interest.</div><div><br></div><div>As part of the Australia's Resources Framework Project, in the Exploring for the Future Program, Geoscience Australia and CSIRO undertook a magnetic source depth study across four areas, with the objectives of generating cover model constraints from magnetic modelling to expand national coverage, and to improve our subsurface understanding of these areas. During this study, 2005 magnetic estimates of depth to the top of magnetization were generated, with solutions derived using a consistent methodology (targeted magnetic inversion modelling, or TMIM; also known as ‘sweet-spot’ modelling). The methodology for these estimates are detailed in a summary report by Foss et al (2024), and is available for download through Geoscience Australia’s enterprise catalogue (https://pid.geoscience.gov.au/dataset/ga/149239). </div><div><br></div><div>The new points were generated over four areas: 1) the western part of Tasmania that is the southernmost extension of the Darling-Curnamona-Delamerian (DCD) project area; 2) northeastern Queensland; 3) the Officer Basin area of western South Australia and southeastern West Australia; and 4) the Eastern Resources Corridor (ERC), covering eastern South Australia, southwest Queensland, western New South Wales and western Victoria. These depth estimates have been released, together with a summary report detailing the data and methodology used to generate the results, through Geoscience Australia's product catalogue (ecat) at https://pid.geoscience.gov.au/dataset/ga/149239.</div><div><br></div><div>This supplementary data release contains the chronostratigraphic attribution of the new TMIM magnetic depth estimates, which range in depth from at surface to 13,294 m below ground. To ensure that the interpretations took into account the local geological features, the magnetic depth estimates were integrated and interpreted with other geological and geophysical datasets, including borehole stratigraphic logs, potential fields images, surface and solid geology maps, and airborne electromagnetic interpretations (where available). </div><div><br></div><div>Each depth-solution is interpretively ascribed to either a chronostratigraphic boundary with the stratigraphic units above and below the depth estimate, or the stratigraphic unit that the depth estimate occurs within, populated from the Australian Stratigraphic Units Database (ASUD). Stratigraphic attribution adds value and informs users of the depth to certain stratigraphic units in their areas of interest. Each solution is accompanied by confidence estimates. The depth estimate points are formatted for compliance with Geoscience Australia’s (GA) Estimates of Geological and Geophysical Surfaces (EGGS) database, the national repository for standardised depth estimate points. </div><div><br></div><div>Results from these interpretations provided some support to stratigraphic drillhole targeting, as part of the Delamerian Margins NSW National Drilling Initiative campaign, a collaboration between GA’s EFTF program, the MinEx CRC National Drilling Initiative and the Geological Survey of New South Wales. The magnetic depth-estimate solutions produced within this study provide important depth constraints in data-poor areas. These data help to construct a better understanding of the 3D geometry of the Australian continent and aid in cover thickness modelling activities. The availability of the depth-estimate solutions via the EGGS database through Geoscience Australia’s Portal creates enduring value to the public.</div>

<div>As part of the Australia's Resources Framework Project, in the Exploring for the Future Program, Geoscience Australia and CSIRO have undertaken a magnetic source depth study across four areas. These are: 1) the western part of Tasmania that is the southernmost extension of the Darling-Curnamona-Delamerian (DCD) project area; 2) northeastern Queensland; 3) the Officer Basin area of western South Australia and southeastern West Australia; and 4) the 'Eastern Resources Corridor' (ERC) covering eastern South Australia, southwest Queensland, western New South Wales and western Victoria. This study has produced 2005 magnetic estimates of depth to the top of magnetization. The solutions are derived by a consistent methodology (targeted magnetic inversion modelling, or TMIM; also known as ‘sweet-spot’ modelling). </div><div><br></div><div>The magnetic depth estimates produced as part of this study provide depth constraints in data-poor areas. They help to construct a better understanding of the 3D geometry of the Australian continent, and aid cover thickness modelling activities. </div><div><br></div><div>A supplementary interpretation data release is also available through Geoscience Australia's enterprise catalogue (ecat) at https://pid.geoscience.gov.au/dataset/ga/149499.</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. This work contributes to building a better understanding of the Australian continent, whilst giving the Australian public the tools they need to help them make informed decisions in their areas of interest.</div>

<div>Near-surface magnetizations are ubiquitous across many areas of Australia and complicate reliable estimation of depth to deeper magnetizations. We have selected four test areas in which we use equivalent source dipoles to represent and quantify the near-surface magnetizations. We present a synthetic modelling study that demonstrates that field variations from the near-surface magnetizations substantially degrade estimation of depth to a magnetization 500 metres below the modelled sensor elevation and that these problems persist even for anomalies with significantly higher amplitudes. However, preferential attenuation of the fields from near surface magnetizations by upward continuation proved quite effective in improving estimation of depth to those magnetizations.</div> This Abstract was submitted/presented at the 2023 Australasian Exploration Geoscience Conference (AEGC) 13-18 March (https://2023.aegc.com.au/)

The Exploring for the Future program Showcase 2023 was held on 15-17 August 2023. Day 2 - 16th August talks included: Highways to Discovery and Understanding Session AusAEM - Unraveling Australia's Landscape with Airborne Electromagnetics – Dr Yusen Ley Cooper Exploring for the Future Data Discovery Portal: A scenic tour – Simon van der Wielen Towards equitable access to regional geoscience information– Dr Kathryn Waltenberg Community engagement and geoscience knowledge sharing: towards inclusive national data and knowledge provision – Dr Meredith Orr Foundational Geoscience Session The power of national scale geological mapping – Dr Eloise Beyer New surface mineralogical and geochemical maps of Australia – Dr Patrice de Caritat Imaging Australia’s Lithospheric Architecture – Dr Babak Hejrani Metallogenic Potential of the Delamerian Margin– Dr Yanbo Cheng You can access the recording of the talks from YouTube here: <a href="https://youtu.be/ZPp2sv2nuXI">2023 Showcase Day 2 - Part 1</a> <a href="https://youtu.be/dvqP8Z5yVtY">2023 Showcase Day 2 - Part 2</a>