The Exploring for the Future program Showcase 2023 was held on 15-17 August 2023. Day 3 - 17th August talks included: Geological Processes and Resources Session Large scale hydrogen storage: The role of salt caverns in Australia’s transition to net zero – Dr Andrew Feitz Basin-Hosted Base Metal Deposits – Dr Evgeniy Bastrakov Upper Darling Floodplain: Groundwater dependent ecosystem assessment – Dr Sarah Buckerfield Atlas of Australian Mine Waste: Waste not, want not – Jane Thorne Resource Potential Theme National-scale mineral potential assessments: supporting mineral exploration in the transition to net zero – Dr Arianne Ford Australia’s Onshore Basin Inventories: Energy – Tehani Palu Prioritising regional groundwater assessments using the national hydrogeological inventory – Dr Steven Lewis Assessing the energy resources potential in underexplored regions – Dr Barry Bradshaw You can access the recording of the talks from YouTube here: <a href="https://youtu.be/pc0a7ArOtN4">2023 Showcase Day 3 - Part 1</a> <a href="https://youtu.be/vpjoVYIjteA">2023 Showcase Day 3 - Part 2</a>

<div>Airborne electromagnetics surveys are at the forefront of addressing the challenge of exploration undercover. They have been essential in the regional mapping programmes to build Australia's resource potential inventory and provide information about the subsurface. In collaboration with state and territory geological surveys, Geoscience Australia (GA) leads a national initiative to acquire AEM data across Australia at 20 km line spacing, as a component of the Australian government Exploring for The Future (EFTF) program. Regional models of subsurface electrical conductivity show new undercover geological features that could host critical mineral deposits and groundwater resources. The models enable us to map potential alteration and structural zones and support environmental and land management studies. Several features observed in the AEM models have also provided insights into possible salt distribution analysed for its hydrogen storage potential. The AusAEM programme is rapidly covering areas with regional AEM transects at a scale never previously attempted. The programme's success leans on the high-resolution, non-invasive nature of the method and its ability to derive subsurface electrical conductivity in three dimensions – made possible by GA's implementation of modern high-performance computing algorithms. The programme is increasingly acquiring more AEM data, processing it, and working towards full national coverage.</div> This Abstract was submitted/presented to the 2023 Australian Exploration Geoscience Conference 13-18 Mar (https://2023.aegc.com.au/)

The High Quality Geophysical Analysis (HiQGA) package is a fully-featured, Julia-language based open source framework for geophysical forward modelling, Bayesian inference, and deterministic imaging. A primary focus of the code is production inversion of airborne electromagnetic (AEM) data from a variety of acquisition systems. Adding custom AEM systems is simple using Julia’s multiple dispatch feature. For probabilistic spatial inference from geophysical data, only a misfit function needs to be supplied to the inference engine. For deterministic inversion, a linearisation of the forward operator (i.e., Jacobian) is also required. HiQGA is natively parallel, and inversions from a full day of production AEM acquisition can be inverted on thousands of CPUs within a few hours. This allows for quick assessment of the quality of the acquisition, and provides geological interpreters preliminary subsurface images of EM conductivity together with associated uncertainties. HiQGA inference is generic by design – allowing for the analysis of diverse geophysical data. Surface magnetic resonance (SMR) geophysics for subsurface water-content estimation is available as a HiQGA plugin through the SMRPInversion (SMR probabilistic inversion) wrapper. The results from AEM and/or SMR inversions are used to create images of the subsurface, which lead to the creation of geological models for a range of applications. These applications range from natural resource exploration to its management and conservation.

The ‘Australia’s Future Energy Resources’ (AFER) project is a four-year multidisciplinary investigation of the potential energy commodity resources in selected onshore sedimentary basins. The resource assessment component of the project incorporates a series of stacked sedimentary basins in the greater Pedirka-western Eromanga region in eastern central Australia. Using newly reprocessed seismic data and applying spatially enabled, exploration play-based mapping tools, a suite of energy commodity resources have been assessed for their relative prospectivity. One important aspects of this study has been the expansion of the hydrocarbon resource assessment work flow to include the evaluation of geological storage of carbon dioxide (GSC) opportunities. This form of resource assessment is likely to be applied as a template for future exploration and resource development, since the storage of greenhouse gases has become paramount in achieving the net-zero emissions target. It is anticipated that the AFER project will be able to highlight future exploration opportunities that match the requirement to place the Australian economy firmly on the path of decarbonisation.

The integrated use of seismic and gravity data can help to assess the potential for underground hydrogen storage in salt caverns in the offshore Polda Basin, South Australia. Geophysical integration software was trialled to perform simultaneous modelling of seismic amplitudes and traveltime information, gravity, and gravity gradients within a 2.5D cross-section. The models were calibrated to existing gravity data, seismic and well logs improving mapping of the salt thickness and depth away from well control. Models included known salt deposits in the offshore parts of the basin and assessed the feasibility for detection of potential salt deposits in the onshore basin, where there is limited well and seismic coverage. The modelling confirms that candidate salt cavern storage sites with salt thicknesses greater than 400-500 m should be detectable on low altitude airborne gravity surveys. Identification of lower cost onshore storage sites will require careful calibration of gravity models against measured data, rather than relying on the observation of rounded anomalies associated with salt diapirism. Ranking of the most prospective storage sites could be optimized after the acquisition of more detailed gravity and gradiometry data, preferably accompanied by seismic reprocessing or new seismic data acquisition.

The Exploring for the Future program Showcase 2023 was held on 15-17 August 2023. Day 1 - 15th August talks included: Resourcing net zero – Dr Andrew Heap Our Geoscience Journey – Dr Karol Czarnota You can access the recording of the talks from YouTube here: <a href="https://youtu.be/uWMZBg4IK3g">2023 Showcase Day 1</a>

Heavy minerals (HMs) have been used successfully around the world in energy and mineral exploration, yet in Australia no public domain database or maps exist that document the background HM assemblages or distributions. Here, we describe a project that delivers the world’s first continental-scale HM maps. We applied automated mineralogical identification and quantification of the 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. Underpinning this vision was a pilot project, based on 10 samples from the national sediment sample archive, which in 2020 demonstrated the feasibility of a larger, national-scale project. Two tranches of the subsequent national HM dataset, one focusing on a 965,000 km2 region centred on Broken Hill in southeastern Australia, the other focusing on a 950,000 km2 area in northern Queensland and Northern Territory, were released in 2022. In those releases, over 47 million mineral grains were analysed in 411 samples, identifying over 150 HM species. We created 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, when released publicly by the end of 2023, will contribute significantly to mineral prospectivity analysis and modelling, particularly for technology critical elements and their host minerals <b>Citation:</b> Caritat P. de, Walker A.T., Bastrakov E. & McInnes B.I.A., 2023. From The Heavy Mineral Map of Australia: vision, implementation and progress. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://dx.doi.org/10.26186/148678

Aims: Groundwater is vital for community water supplies and economic development in Australia. It also supports indigenous cultural values and sustains a range of groundwater dependent ecosystems, including springs and vegetation communities. Geoscience Australia’s regional assessments and basin inventories are investigating Australia’s groundwater systems to improve knowledge of the nation’s groundwater systems under the Exploring for the Future (EFTF) Program. Where applicable, we applied integrated basin analysis workflows to build models of geological and hydrostratigraphic architecture and link them to a nationally consistent chronostratigraphic framework. While the focus of this paper is the Great Artesian Basin (GAB), the overlying Lake Eyre Basin (LEB) and the Upper Darling Floodplain (UDF) region, these datasets and surfaces continue expanding beyond this current study area by linking additional studies using this consistent approach, towards building a national picture of groundwater systems. Method: Geoscience Australia continues to refine the chronostratigraphic framework that correlates time equivalent geological units from neighbouring basins and hydrostratigraphy for the GAB, LEB and UDF (Figure 1), infilling key data and knowledge gaps from previous compilations and adding new interpretation. In collaboration with Commonwealth, State and Territory government agencies, we compiled and standardised data from thousands of boreholes, including stratigraphic (Norton & Rollet, 2023; Vizy & Rollet, 2023a) and biostratigraphic picks (Hannaford & Rollet, 2023), 2D and 3D seismic (Szczepaniak et al., 2023) and airborne electromagnetic derived conductivity sections across the study area (McPherson et al., 2022a &b; Wong et al., 2023). We undertook a detailed stratigraphic review of thousands of boreholes with geophysical logs to construct consistent regional transects across the GAB, LEB and UDF (Norton & Rollet, 2023). In addition we applied geological time constraints from hundreds of boreholes with existing and newly interpreted biostratigraphic data (including from legacy palynological preparations from the Geoscience Australia archives where old reports could not be found) (Hannaford & Rollet, 2023). New biostratigraphic data from core samples has been analysed from bores in the Northern Territory, South Australia and Queensland. The biostratigraphic data was calibrated to the most recent biostratigraphic zonation scheme and used to provide geological time constraint to the stratigraphic picks. Results: We infilled the stratigraphic correlations along key transects across Queensland, New South Wales, South Australia and the Northern Territory to refine nomenclature and stratigraphic relationships between the Surat, Eromanga and Carpentaria basins, improving chronostratigraphic understanding within the Jurassic‒Cretaceous to Cenozoic units. We extended the GAB geological framework to include the overlying LEB and UDF as well to better resolve the Cenozoic stratigraphy and structure and potential for hydrogeological connectivity. The new data and information fill recognised gaps and refine the previous 3D geological model of the entire GAB and extend it to the LEB and UDF region (Vizy & Rollet, 2023b). The updated 3D geological and hydrostratigraphic model provides a framework to integrate additional hydrogeological and rock property data. It assists in refining hydraulic relationships between aquifers within the GAB, LEB, UDF and provides a basis for developing more detailed hydrogeological system conceptualisations. The improved cross-jurisdictional chronostratigraphic understanding supports improvements to the common agreed terminology for Australian hydrogeological units and groundwater provinces between jurisdiction borders (http://www.bom.gov.au/water/groundwater/naf/). This enables the delivery of geologically and hydrogeologically consistent datasets to inform decision makers and the broader groundwater community in Australia. This abstract was submitted/presented to the 2023 Australasian Groundwater / New Zealand Hydrological Society (AGC NZHS) Joint Conference (https://www.hydrologynz.org.nz/events-1/australasian-groundwater-nzhs-joint-conference) References: Hannaford, C. and Rollet, N. 2023. Palynological data review of selected boreholes in the Great Artesian, Lake Eyre basins and Upper Darling Floodplain (part 2): Infilling data and knowledge gaps. Record 2023/27. Geoscience Australia, Canberra. https://dx.doi.org/10.26186/147173 McPherson, A., Rollet, N., Vizy, J., Kilgour, P. 2022a. Great Artesian Basin eastern recharge area assessment - northern Surat Basin airborne electromagnetic survey interpretation report. RECORD: 2022/017. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/Record.2022.017 McPherson, A., Buckerfield, S., Tan, K., Kilgour, P., Symington, N., Ray, A., Buchanan, S. 2022b. Developing (hydro)geological conceptual models to support improved groundwater management. The Upper Darling Floodplain Project, New South Wales. Geoscience Australia, Canberra. https://dx.doi.org/10.26186/147055 Norton, C. J. and Rollet, N. 2023. Regional stratigraphic correlation transects across the Great Artesian, Lake Eyre basins and Upper Darling Floodplain region (part 2): Infilling data and knowledge gaps. Record 2023/28. Geoscience Australia, Canberra. https://dx.doi.org/10.26186/147243 Szczepaniak, M., Rollet, N., Bradshaw, B, Lund, D., Iwanec, J., Bradey, K., Vizy, J., 2023. Western and central Eromanga and underlying basins seismic interpretation ‒ Data package. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/147900 Vizy, J. & Rollet, N. 2023a. Australian Borehole Stratigraphic Units Compilation (ABSUC) 2023 Version 1.0. Geoscience Australia, Canberra. https://dx.doi.org/10.26186/147641 Vizy, J. & Rollet, N., 2023b. 3D geological and hydrogeological surfaces update in the Great Artesian, Lake Eyre basins and Upper Darling Floodplain region (part 2): report and data package. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/148552 Wong, S.C.T., Hegarty, R.A., Pitt, L., Crowe, M.C., Roach, I., Nicoll, M., LeyCooper, Y., Hope, J., Bonnardot, M. 2023. Eastern Resources Corridor Airborne Electromagnetic Interpretation Data Package. Geoscience Australia, Canberra. https://dx.doi.org/10.26186/147992

Carbon capture and storage (CCS) is a central component of many proposed pathways to reach net zero CO2 emissions by 2050. Even under conservative estimates, successful deployment of CCS projects at scale will require a substantial investment in the selection and development of new sequestration sites. While several studies have considered the potential costs associated with individual sequestration projects, and others have evaluated the costs of capture and sequestration in a generic manner, few have examined how regional differences in transport distances and reservoir properties may affect the overall costs of sequestration projects. In this abstract, we outline a new model to assess the costs associated with new carbon sequestration projects. The model evaluates the cost of CCS projects accounting for regional variations in transport distance and cost and well the storage properties of individual reservoirs. We present preliminary results from the modelling tool, highlighting potential opportunities for new CCS projects.

Exploring for the Future is an Australian Government program led by Geoscience Australia that aims to drive investment in the resources and agricultural sectors by providing industry and land and water managers with pre-competitive data about potential mineral, energy and groundwater resources. The Australian Government invested $100 million in the first phase of the Exploring for the Future program in 2016. In June 2020, the Australian Government announced a $125 million extension and expansion of the program, bringing their total investment to $225 million to date. Exploring for the Future is building on Geoscience Australia's deep domain knowledge to generate new science and challenge the frontiers of resource exploration. Eight new projects will include the southern half of the continent, with a focus on two potentially resource-rich corridors that stretch across the country. Unlocking these new resource corridors will provide ongoing economic and employment growth across a wide range of regional areas.