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  • Geothermal energy is a renewable energy technology reported to have a large potential resource base. However, existing geothermal data for Australia (borehole temperatures and heat flow determinations), are limited and collection of additional data is both time consuming and restricted to accessing to wells drilled for other purposes. It is therefore important to develop "deposit" or resource models to aid exploration; improving the quality of subsurface thermal estimates, and helping to identify the distal footprints of geothermal systems. Conceptually, the fundamental requirements of a geothermal system are well understood. However, the complex interplay between the various elements makes it difficult to compare different geographical regions and to assess their relative prospectively. As such, the results of some 130,000 synthetic thermal-modelling runs have been used to calibrate a new tool called the 'Geothermal Calculator'. The Calculator acts as an emulator, or surrogate model, falling into a class of functions which seek to approximate the input / output behaviour of more-complex systems. This presentation will explore the mechanics of the Calculator, before examining some of its possible uses; from simple point-spot estimates to the broader continental scale. The functionality of the Geothermal Calculator presents a significant step forward in our ability to produce subsurface temperature estimates, and represents a notable milestone in the pathway to realising our subsurface geothermal energy potential.

  • <div>This report presents thermal property data (thermal conductivity data, calculated heat production data, and calculated surface heat flow) from the deep (1751 m) stratigraphic drill hole, NDI Carrara 1. Thermal conductivity analyses were undertaken at the University of Melbourne. Heat production values were calculated from existing whole rock geochemical data. Surface heat flow was determined using the laboratory thermal conductivity data together with in situ downhole temperature data collected previously.</div>

  • The Geoscience Australia Rock Properties database stores the result measurements of scalar and vector petrophysical properties of rock and regolith specimens and hydrogeological data. Oracle database and Open Geospatial Consortium (OGC) web services. Links to Samples, Field Sites, Boreholes. <b>Value:</b> Essential for relating geophysical measurements to geology and hydrogeology and thereby constraining geological, geophysical and groundwater models of the Earth <b>Scope:</b> Data are sourced from all states and territories of Australia

  • <div><strong>Output Type: </strong>Exploring for the Future Extended Abstract</div><div><br></div><div><strong>Short Abstract: </strong>The thickness and thermal structure of continental lithosphere influences the location of seismic and volcanic hazards and is important for predicting long-term evolution of landscapes, sedimentary basins, and the distribution of natural resources. In this project, we have developed new, continental-scale models of the thermomechanical structure of the Australian plate. We begin by compiling an inventory of >15,000 geochemical analyses of peridotitic xenoliths and xenocrysts from across the continent that have been carried up to the surface in volcanic eruptions. We apply thermobarometric techniques to constrain their pressure and temperature of equilibration and perform steady-state heat flow modelling to assess the paleogeotherm beneath these sites. We subsequently use the paleogeotherms as constraints in a Bayesian calibration of anelasticity at seismic frequencies to provide a mapping between seismic velocity and temperature as a function of pressure. We apply this method to several regional-scale seismic tomography models, allowing the temperature to be continuously mapped throughout the Australian lithospheric and asthenospheric mantle. Our models include assessment of uncertainties and can be used to query thermomechanical properties, such as lithospheric thickness, heat flow through the Moho, and the Curie depth.</div><div><br></div><div><strong>Citation: </strong>Hoggard, M.J., Hazzard, J., Sudholz, Z., Richards, F., Duvernay, T., Austermann, J., Jaques, A.L., Yaxley, G., Czarnota, K. & Haynes, M., 2024. Thermochemical models of the Australian plate. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra. https://doi.org/10.26186/149411</div>

  • <div>Diamond exploration over the past decade has led to the discovery of a new province of kimberlitic pipes (the Webb Province) in the Gibson Desert of central Australia. The Webb pipes comprise sparse macrocrystic olivine set in a groundmass of olivine, phlogopite, perovskite, spinel, clinopyroxene, titanian-andradite and carbonate. The pipes resemble ultramafic lamprophyres (notably aillikites) in their mineralogy, major and minor oxide chemistry, and initial 87Sr/ 86Sr and <em>ε</em>Nd-<em>ε</em>Hf isotopic compositions. Ion probe U-Pb geochronology on perovskite (806 ± 22 Ma) indicates the eruption of the pipes was co-eval with plume-related magmatism within central Australia (Willouran-Gairdner Volcanic Event) associated with the opening of the Centralian Superbasin and Rodinia supercontinent break-up. The equilibration pressure and temperature of mantle-derived garnet and chromian (Cr) diopside xenocrysts range between 17 and 40 kbar and 750–1320°C and define a paleo-lithospheric thickness of 140 ± 10 km. Chemical variations of xenocrysts define litho-chemical horizons within the shallow, middle, and deep sub-continental lithospheric mantle (SCLM). The shallow SCLM (50–70 km), which includes garnet-spinel and spinel lherzolite, contains Cr diopside with weakly refertilized rare earth element compositions and unenriched compositions. The mid-lithosphere (70–85 km) has lower modal abundances of Cr diopside. This layer corresponds to a seismic mid-lithosphere discontinuity interpreted as pargasite-bearing lherzolite. The deep SCLM (&gt;90 km) comprises refertilized garnet lherzolite that was metasomatized by a silicate-carbonatite melt.</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). Petrology, age, and rift origin of ultramafic lamprophyres (aillikites) at Mount Webb, a new alkaline province in Central Australia. <i>Geochemistry, Geophysics, Geosystems</i>, 24, e2023GC011120.</div><div>https://doi.org/10.1029/2023GC011120</div>

  • <div>Australia’s Energy Commodity Resources (AECR) 2024 provides estimates of Australia’s energy commodity reserves, resources, and production as at the end of 2022. The 2024 edition of AECR also includes previously unpublished energy commodity resource estimates data compiled by Geoscience Australia for the 2022 reporting period. The AECR energy commodity resource estimates are based primarily on published open file data and aggregated (de-identified) confidential data. The annual assessment provides a baseline for the production and remaining recoverable resources of gas, oil, coal, uranium and thorium in Australia, and the global significance of our nation’s energy commodity resources. The publication also presents chapters on the status of emerging clean energy resources in Australia, including geothermal, carbon capture and storage (CCS) and hydrogen.</div>

  • A new approach for developing a 3D temperature map of the Australian continent has been trialled that combines available proxy data using high-performance computing and large continental-scale datasets. The Thermal Map from Assessed Proxies (TherMAP) is a new 3D modelling approach that brings together up-to-date national-scale datasets. Bringing together such a range of datasets provides a geoscientific basis by which to estimate temperature in regions where direct observations are not available. Furthermore, the National Computational Infrastructure (NCI) is enabling insights into the nature of Australia's geothermal resources that had not been previously available.

  • This map presents radiogenic crustal heat production values calculated from available geochemical data from basement rock exposures from across the Australian Antarctic Territory (AAT). Heat production is derived from the radiogenic decay of the radioactive elements, primarily, U, Th and K. This map, along with the companion GA record (2012/63), highlights the magnitude and heterogeneity of crustal heat production across the AAT, and provides earth scientists with the first crustal heat production assessment across much of East Antarctica. Crustal heat production values across the AAT show a wide range from negligible to as much as 65 'Wm-3. Generally, elevated heat production values are characteristic of Cambrian felsic intrusives, with intermediate values from Proterozoic intrusive and metasediments (2-8 Wm-3), and low values (<2 'Wm-3) from Archean rocks. A good illustration of the correlation of geological age with heat production is from Prydz Bay (map 5), where the Vestfold Hills (mostly ~2500 Ma in age) exhibits uniformly low heat production (average ~0.8 'Wm-3), whereas Proterozoic rocks south of the Vestfold Hills have intermediate values (average ~2.6 'Wm-3). Cambrian intrusives, in contrast, have significantly elevated values (average ~15 'Wm-3). We anticipate that this simple compilation of crustal heat production may form a basis for future studies on the thermal structure of the East Antarctic crust, in particular, sub-glacial heat flow, which remains a critical, yet poorly characterised, boundary parameter controlling the dynamic behaviour of the vast Antarctic ice sheet. For further information and data tables, the reader is referred to 'A reconnaissance crustal heat production assessment of the Australian Antarctic Territory (AAT)' by C. J. Carson and M. Pittard, GA record 2012/063 (pp 57), Geocat 74073.

  • <div>Lithospheric structure and composition have direct relevance for our understanding of mineral prospectivity. Aspects of the lithosphere can be imaged using geophysical inversion or analysed from exhumed samples at the surface of the Earth, but it is a challenge to ensure consistency between competing models and datasets. The LitMod platform provides a probabilistic inversion framework that uses geology as the fabric to unify multiple geophysical techniques and incorporates a priori geochemical information. Here, we present results from the application of LitMod to the Australian continent. The rasters summarise the results and performance of a Markov-chain Monte Carlo sampling from the posterior model space. Release KY22 is developed using the primary-mode Rayleigh phase velocity grids of Yoshizawa (2014).</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>

  • <p>The Geological Survey of South Australia commissioned the Gawler Craton Airborne Survey (GCAS) as part of the PACE Copper initiative. The airborne geophysical survey was flown over parts of the Gawler Craton in South Australia. The program was designed to capture new baseline geoscientific data to provide further information on the geological context and setting of the area for mineral systems (http://energymining.sa.gov.au/minerals/geoscience/pace_copper/gawler_craton_airborne_survey). <p>The survey design of 200 m spaced lines at a ground clearance of 60 m can be compared with the design of previous regional surveys which generally employed 400 m line spacing and a ground clearance of 80 m. The new survey design results in ~2 x the data coverage and ~25% closer to the ground when compared to previous standards for regional surveys in South Australia. <p>Survey blocks available for download include: <p>Streaky Bay, block 5 <p>Gairdner, block 6A <p>Spencer, block 7 <p>Kingoonya, block 9B <p>The following grids are available in this download: <p>• Laser-derived digital elevation model grids (m). Height relative to the Australian Height Datum. <p>• Radar-derived digital elevation model grids (m). Height relative to the Australian Height Datum. <p>• Total magnetic intensity grid (nT). <p>• Total magnetic intensity grid with variable reduction to the pole applied (nT). <p>• Total magnetic intensity grid with variable reduction to the pole and first vertical derivative applied (nT/m). <p>• Dose rate concentration grid (nGy/hr). <p>• Potassium concentration grid (%). <p>• Thorium concentration grid (ppm). <p>• Uranium concentration grid (ppm). <p>• NASVD processed dose rate concentration grid (nGy/hr). <p>• NASVD processed potassium concentration grid (%). <p>• NASVD processed thorium concentration grid (ppm). <p>• NASVD processed uranium concentration grid (ppm). <p>The following point located data are available in this download: <p>• Elevation. Height relative to the Australian Height Datum. Datum: GDA94 <p>• Total Magnetic Intensity. Datum: GDA94 <p>• Radiometrics. Datum: GDA94