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  • Long-range, active-source airborne electromagnetic (AEM) systems for near-surface imaging fall into two categories: helicopter borne or fixed-wing aircraft borne. A multitude of factors such as flying height, transmitter loop area and current, source waveforms, aerodynamic stability and data stacking times contribute to the geological resolvability of the subsurface. A comprehensive comparison of the relative merits of each system considering all such factors is difficult, but test flights over known subsurface geology with downhole induction logs are extremely useful for resolution studies. Further, given the non-linear nature of the electromagnetic inverse problem, handling transmitter-receiver geometries in fixed-wing aircraft is especially challenging. As a consequence of this nonlinearity, inspecting the closeness of downhole conductivities to deterministic inversion results is not sufficient for studying resolvability. A more comprehensive picture is provided by examining the width of the depth-wise Bayesian posterior conductivity distributions for each kind of system. For this purpose, probabilistic inversions of data must be carried out -- with acquisition over the same geology, survey noise levels must be measured, and the same prior probabilities on conductivity must be used. With both synthetic models as well as real data from over the Menindee calibration range in New South Wales, Australia, we shed new light on the matter of AEM inverse model resolution. Specifically, we use a novel Bayesian inversion scheme which handles fixed-wing geometry attributes as generic nuisance parameters during Markov chain sampling. Our findings have useful implications in AEM system selection, as well as in the design of better deterministic AEM inversion algorithms. <b>Citation:</b> Anandaroop Ray, Yusen Ley-Cooper, Ross C Brodie, Richard Taylor, Neil Symington, Negin F Moghaddam, An information theoretic Bayesian uncertainty analysis of AEM systems over Menindee Lake, Australia, Geophysical Journal International, Volume 235, Issue 2, November 2023, Pages 1888–1911, <a href="https://doi.org/10.1093/gji/ggad337">https://doi.org/10.1093/gji/ggad337</a>

  • Alkaline and related rocks are a relatively rare class of igneous rocks worldwide. Alkaline rocks encompass a wide range of rock types and are mineralogically and geochemically diverse. They are typically though to have been derived by generally small to very small degrees of partial melting of a wide range of mantle compositions. As such these rocks have the potential to convey considerable information on the evolution of the Earth’s mantle (asthenosphere and lithosphere), particularly the role of metasomatism which may have been important in their generation or to which such rocks may themselves have contributed. Such rocks, by their unique compositions and or enriched source protoliths, also have considerable metallogenic potential, e.g., diamonds, Th, U, Zr, Hf, Nb, Ta, REEs. It is evident that the geographic occurrences of many of these rock types are also important, and may relate to presence of old cratons, craton margins or major lithospheric breaks. Finally, many alkaline rocks also carry with them mantle xenoliths providing a snapshot of the lithospheric mantle composition at the time of their emplacement. Accordingly, although alkaline and related rocks comprise only a volumetrically minor component of the geology of Australia, they are of considerable importance to studies of lithospheric composition, evolution and architecture and to helping constrain the temporal evolution of the lithosphere, as well as more directly to metallogenesis and mineralisation. This contribution presents data on the distribution and geology of Australian alkaline and related rocks of Mesozoic age. The report and accompanying GIS document the distribution, age, lithology, mineralogy and other characteristics of these rocks (e.g., extrusive/intrusive, presence of mantle xenoliths, presence of diamonds), as well as references for data sources and descriptions. The report also reviews the nomenclature of alkaline rocks and classification procedures. GIS metadata are documented in the appendices.

  • Alkaline and related rocks are a relatively rare class of igneous rocks worldwide. Alkaline rocks encompass a wide range of rock types and are mineralogically and geochemically diverse. They are typically though to have been derived by generally small to very small degrees of partial melting of a wide range of mantle compositions. As such these rocks have the potential to convey considerable information on the evolution of the Earth’s mantle (asthenosphere and lithosphere), particularly the role of metasomatism which may have been important in their generation or to which such rocks may themselves have contributed. Such rocks, by their unique compositions and or enriched source protoliths, also have considerable metallogenic potential, e.g., diamonds, Th, U, Zr, Hf, Nb, Ta, REEs. It is evident that the geographic occurrences of many of these rock types are also important, and may relate to presence of old cratons, craton margins or major lithospheric breaks. Finally, many alkaline rocks also carry with them mantle xenoliths providing a snapshot of the lithospheric mantle composition at the time of their emplacement. Accordingly, although Alkaline and related rocks comprise only a volumetrically minor component of the geology of Australia, they are of considerable importance to studies of lithospheric composition, evolution and architecture and to helping constrain the temporal evolution of the lithosphere, as well as more directly to metallogenesis and mineralisation. This GIS product is part of an ongoing compilation of the distribution and geology of alkaline and related rocks throughout Australia. The accompanying report document alkaline and related rocks of Mesozoic age.

  • <div>Alkaline and related rocks are a relatively rare class of igneous rocks worldwide. Alkaline rocks encompass a wide range of rock types and are mineralogically and geochemically diverse. They are typically though to have been derived by generally small to very small degrees of partial melting of a wide range of mantle compositions. As such these rocks have the potential to convey considerable information on the evolution of the Earth’s mantle (asthenosphere and lithosphere), particularly the role of metasomatism which may have been important in their generation or to which such rocks may themselves have contributed. Such rocks, by their unique compositions and or enriched source protoliths, also have considerable metallogenic potential, e.g., diamonds, Th, U, Zr, Hf, Nb, Ta, REEs. It is evident that the geographic occurrences of many of these rock types are also important, and may relate to presence of old cratons, craton margins or major lithospheric breaks. Finally, many alkaline rocks also carry with them mantle xenoliths providing a snapshot of the lithospheric mantle composition at the time of their emplacement.</div><div><br></div><div>Accordingly, although Alkaline and related rocks comprise only a volumetrically minor component of the geology of Australia, they are of considerable importance to studies of lithospheric composition, evolution and architecture and to helping constrain the temporal evolution of the lithosphere, as well as more directly to metallogenesis and mineralisation.</div><div><br></div><div>This GIS product is part of an ongoing compilation of the distribution and geology of alkaline and related rocks throughout Australia. The accompanying report document alkaline and related rocks of Paleozoic age.</div>

  • <div>Alkaline and related rocks are a relatively rare class of igneous rocks worldwide. Alkaline rocks encompass a wide range of rock types and are mineralogically and geochemically diverse. They are typically though to have been derived by generally small to very small degrees of partial melting of a wide range of mantle compositions. As such these rocks have the potential to convey considerable information on the evolution of the Earth’s mantle (asthenosphere and lithosphere), particularly the role of metasomatism which may have been important in their generation or to which such rocks may themselves have contributed. Such rocks, by their unique compositions and or enriched source protoliths, also have considerable metallogenic potential, e.g., diamonds, Th, U, Zr, Hf, Nb, Ta, REEs. It is evident that the geographic occurrences of many of these rock types are also important, and may relate to presence of old cratons, craton margins or major lithospheric breaks. Finally, many alkaline rocks also carry with them mantle xenoliths providing a snapshot of the lithospheric mantle composition at the time of their emplacement.</div><div><br></div><div>Accordingly, although Alkaline and related rocks comprise only a volumetrically minor component of the geology of Australia, they are of considerable importance to studies of lithospheric composition, evolution and architecture and to helping constrain the temporal evolution of the lithosphere, as well as more directly to metallogenesis and mineralisation.</div><div><br></div><div>This GIS product is part of an ongoing compilation of the distribution and geology of alkaline and related rocks throughout Australia. The accompanying report document alkaline and related rocks of Cenozoic age.</div>

  • The Exploring for the Future program Showcase 2024 was held on 13-16 August 2024. Day 3 - 15th August talks included: <b>Session 1 – Hydrogen opportunities across Australia</b> <a href="https://youtu.be/pA9ft3-7BtU?si=V0-ccAmHHIYJIZAo">Hydrogen storage opportunities and the role of depleted gas fields</a> - Dr Eric Tenthorey <a href="https://youtu.be/MJFhP57nnd0?si=ECO7OFTCak78Gn1M">The Green Steel Economic Fairways Mapper</a> - Dr Marcus Haynes <a href="https://youtu.be/M95FOQMRC7o?si=FyP7CuDEL0HEdzPw">Natural hydrogen: The Australian context</a> - Chris Boreham <b>Session 2 – Sedimentary basin resource potential – source rocks, carbon capture and storage (CCS) and groundwater</b> <a href="https://youtu.be/44qPlV7h3os?si=wfQqxQ81Obhc_ThE">Australian Source Rock and Fluid Atlas - Accessible visions built on historical data archives</a> - Dr Dianne Edwards <a href="https://youtu.be/WcJdSzsADV8?si=aH5aYbpnjaz3Qwj9">CO2: Where can we put it and how much will it cost?</a> - Claire Patterson <a href="https://youtu.be/Y8sA-iR86c8?si=CUsERoEkNDvIwMtc">National aquifer framework: Putting the geology into hydrogeology</a> - Dr Nadege Rollet <b>Session 3 – Towards a national inventory of resource potential and sustainable development</b> <a href="https://youtu.be/K5xGpwaIWgg?si=2s0AKuNpu30sV1Pu">Towards a national inventory of mineral potential</a> - Dr Arianne Ford <a href="https://youtu.be/XKmEXwQzbZ0?si=yAMQMjsNCGkAQUMh">Towards an inventory of mine waste potential</a> - Dr Anita Parbhakar-Fox <a href="https://youtu.be/0AleUvr2F78?si=zS4xEsUYtARywB1j">ESG mapping of the Australian mining sector: A critical review of spatial datasets for decision making</a> - Dr Eleonore Lebre View or download the <a href="https://dx.doi.org/10.26186/149800">Exploring for the Future - An overview of Australia’s transformational geoscience program</a> publication. View or download the <a href="https://dx.doi.org/10.26186/149743">Exploring for the Future - Australia's transformational geoscience program</a> publication. You can access full session and Q&A recordings from YouTube here: 2024 Showcase Day 3 - Session 1 - <a href="https://www.youtube.com/watch?v=Ho6QFMIleuE">Hydrogen opportunities across Australia</a> 2024 Showcase Day 3 - Session 2 - <a href="https://www.youtube.com/watch?v=ePZfgEwo0m4">Sedimentary basin resource potential – source rocks, carbon capture and storage (CCS) and groundwater</a> 2024 Showcase Day 3 - Session 3 - <a href="https://www.youtube.com/watch?v=CjsZVK4h6Dk">Towards a national inventory of resource potential and sustainable development</a>

  • This airborne electromagnetic (AEM) dataset provides regional scale probabilistic inversion products from 141,000 line km of airborne electromagnetic (AEM) data from the AusAEM program. The two main benefits of a probabilistic inversion over a deterministic one are: - Loss of signal sensitivity at depth does not “fade to blue” by returning to the resistive deterministic reference model. - Ambiguous subsurface features become clearer when examining multiple probability percentiles. Further details are provided in the accompanying technical note. Conductivity products from the following surveys are available: - Frome 2011 - AusAEM 1 NT (2017) - AusAEM 1 QLD (2017) - AusAEM 2 Tranche 1 part (2019) - AusAEM 3 Eastern Resources Corridor (all 3 phases) - AusAEM 3 Western Resources Corridor (Kimberley, Central, Musgraves and South) The 10th, 50th and 90th and mean percentiles of log10 conductivity are provided in a variety of formats: - VTK structured grids - ASCII point clouds - ASEG-GDF2 files - GOCAD S-grids All products have been provided in the coordinate reference system (CRS) the original AEM data were provided in. The VTK unstructured grids are also provided in GDA94 geodetic longitude, latitude coordinates for ease of display in the same CRS.

  • <div>Geoscience Australia’s Exploring for the Future (EFTF) 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>This record contains geological notes on layered geology interpretation of twenty-nine 1:250 000 Sheet areas in eastern Queensland. The geology maps generated as part of this work were not released as a separate product but incorporated into the national layered geology product of Sanchez et al. (2024). There are five layers interpreted; pre-Neoproterozoic, Neoproterozoic, Paleozoic, Mesozoic and Cenozoic. Preparation of these layers involved figuratively peeling off successively older rocks and identifying and outlining the rocks thereby revealed. The notes provide comments on the rocks comprising each layer, and explain how the identity of the revealed rocks was arrived at where this is not obvious. The Cenozoic time slice was extracted from the 1:1 000 000 scale outcrop geology (Raymond et al., 2012) after removing the surficial deposits and without further interpretation.&nbsp;</div>

  • <div>The energy and resources industries are two essential pillars of Australia’s economy and vital sectors in the global transition to a sustainable and net-zero economy. To enhance Australia’s competitiveness, there is an urgent need to explore technical and strategic challenges and opportunities to unlock domestic hydrogen and green steel development pathways that are suitable for the Australian resources and manufacturing ecosystem. </div><div><br></div><div>Held on 30 August 2023 in Perth, Western Australia, this workshop provided Australian stakeholders in the hydrogen, iron ore and government sectors a forum to share, discuss and provide insight on a broad range of aspects relevant to hydrogen and green steel development opportunities across Australia—including identifying investment hurdles, technical challenges and knowledge gaps, and fostering new innovation and collaboration opportunities.</div><div><br></div><div>As part of the Exploring for the Future program, Geoscience Australia, in collaboration with Monash University, premiered its Green Steel Economic Fairways tool, which utilises geoscience knowledge and data to highlight regional opportunities of high economic potential for hydrogen and green steel industries in Australia.</div><div><br></div><div>The recording of the workshop presentations is available on YouTube.</div>

  • <div>The production of rare earth elements is critical for the transition to a low carbon economy. Carbonatites (&gt;50% carbonate minerals) are one of the most significant sources of rare earth elements (REEs), both domestically within Australia, as well as globally. Given the strategic importance of critical minerals, including REEs, for the Australian national economy, a mineral potential assessment has been undertaken to evaluate the prospectivity for carbonatite-related REE (CREE) mineralisation in Australia. CREE deposits form as the result of lithospheric- to deposit-scale processes that are spatially and temporally coincident.</div><div><br></div><div>Building on previous research into the formation of carbonatites and their related REE mineralisation, a mineral system model has been developed that incorporates four components: (1) source of metals, fluids, and ligands, (2) energy sources and fluid flow drivers, (3) fluid flow pathways and lithospheric architecture, and (4) ore deposition. This study demonstrates how national-scale datasets and a mineral systems-based approach can be used to map the mineral potential for CREE mineral systems in Australia.</div><div><br></div><div>Using statistical analysis to guide the feature engineering and map weightings, a weighted index overlay method has been used to generate national-scale mineral potential maps that reduce the exploration search space for CREE mineral systems by up to ∼90%. In addition to highlighting regions with known carbonatites and CREE mineralisation, the mineral potential assessment also indicates high potential in parts of Australia that have no previously identified carbonatites or CREE deposits.</div><div><br></div><div><b>Citation: </b>Ford, A., Huston, D., Cloutier, J., Doublier, M., Schofield, A., Cheng, Y., and Beyer, E., 2023. A national-scale mineral potential assessment for carbonatite-related rare earth element mineral systems in Australia, <i>Ore Geology Reviews</i>, V. 161, 105658. https://doi.org/10.1016/j.oregeorev.2023.105658</div>