Presentation to Australian Research Council (ARC) Training Centre for Data Analytics in Resources and Environment (DARE) Symposium (17 February 2023, University of Sydney) demonstrating use of uncertainty in hydrogeophysical applications as part of the Upper Darling River Floodplain EFTF project.

A large proportion of Australia’s onshore sedimentary basins remain exploration frontiers. Industry interest in these basins has recently increased due to the global and domestic energy demand, and the growth in unconventional hydrocarbon exploration. In 2016 and 2018, Geoscience Australia released an assessment of several central Australian basins that summarised the current status of geoscientific knowledge and petroleum exploration, and the key questions, for each basin. This publication provides a comprehensive assessment of the geology, petroleum systems, exploration status and data coverage for the Adavale Basin.

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).

As part of the Exploring For the Future program 2022 showcase, Geoscience Australia (GA) in collaboration with the Australian Institute of Geoscientists held an Airborne Electromagnetics (AEM) workshop in Perth on 11th August 2022. The workshop comprised the following: - An introduction to GA's 20 km spaced continent-wide AusAEM program, by Karol Czarnota - How the Western Australia government has successfully used 20 km spaced AEM data, by Klaus Gessner - An introduction to AEM, surveying, and quality control given by Yusen Ley-Cooper - An introduction to inverse theory presented by Anandaroop Ray - Hands-on AEM modeling and inversion using HiQGA.jl by Anandaroop Ray - Integrating geophysics and geology in subsurface interpretation, by Sebastian Wong - Avoiding the 10 most common pitfalls in AEM interpretation according to Neil Symington YouTube video from the workshop, as well as data and code to follow along with the videos can be found on GA's GitHub at <a href=https://github.com/GeoscienceAustralia/HiQGA.jl/tree/workshop><u>this link.</u></a>

Exploring for the Future (EFTF) is an Australian Government initiative that gathers new data and information about potential mineral, energy and groundwater resources. Commencing in 2016 with a focus on northern Australia, an EFTF extension to 2024 was recently announced, with expanded coverage across mainland Australia and Tasmania. The EFTF energy component aims to improve our understanding of the petroleum potential of frontier onshore Australian basins and has acquired significant pre-competitive datasets, including the recently drilled Barnicarndy 1 deep stratigraphic well in Western Australia’s Canning Basin (in partnership with the Geological Survey of Western Australia), and NDI Carrara 1 deep stratigraphic well in the South Nicholson region of the Northern Territory (in partnership with the MinEX CRC). These are the first stratigraphic wells drilled in a petroleum basin by Geoscience Australia since the formation in 2001 from its predecessor agencies. Both wells were sited along two-dimensional, deep crustal seismic surveys acquired by Geoscience Australia as part of EFTF, and provide stratigraphic control for the imaged geology. The sedimentary fill intersected by the Barnicarndy 1 and NDI Carrara 1 wells were cored and logged with a broad suite of wireline tools, providing substantial new data in two frontier basins. These data provide insights into regional stratigraphy and local lithology. Geochronology, petrographic, organic and inorganic geochemistry, petrophysical rock properties, petroleum systems elements, palaeontological, and fluid inclusion studies have been undertaken upon which inferences on regional prospectivity can made in these data-poor regions. Moving into the next phase of EFTF, these wells provide a template for new pre-competitive data acquisition by Geoscience Australia, expanding our knowledge of frontier regions making them attractive for new investment and exploration.

This animation shows how Airborne Electromagnetic Surveys Work, when conducted by a rotary wing (helicopter) aircraft. It is part of a series of Field Activity Technique Engagement Animations. The target audience are the communities that are impacted by our data acquisition activities. There is no sound or voice over. The 2D animation includes a simplified view of what AEM equipment looks like, what the equipment measures and how the survey works.

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

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

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. The name ‘Birrindudu Basin’ was first introduced by Blake et al. (1975) and Sweet (1977) for a succession of clastic sedimentary rocks and carbonates, originally considered to be Paleoproterozoic to Neoproterozoic in age, and overlain by the Neoproterozoic Victoria Basin (Dunster et al., 2000), formerly known as the Victoria River Basin (see Sweet, 1977).

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.