<div>Alkaline igneous and related rocks are recognised as a significant source of the critical minerals essential for Australia’s transition to net-zero. Understanding these small but economically significant group of poorly mapped rocks is essential for identifying their resource potential. The Australian Alkaline Rocks Atlas aims to capture all known occurrences of these volumetrically minor, but important, igneous rocks in a national compilation, to aid understanding of their composition, distribution and age at the continental scale. The Atlas, comprises five, stand-alone data packages covering the Archean, Proterozoic, Paleozoic, Mesozoic and Cenozoic eras. Each data package includes a GIS database and detailed accompanying report that informs alkaline rock nomenclature, classification procedures, individual units and their grouping into alkaline provinces based on common age, characteristics and inferred genesis. The Alkaline Rocks Atlas will form a foundation for more expansive research on related mineral systems and their corresponding economic potential being undertaken as part of the EFTF program. To illustrate the use of the Alkaline Rocks Atlas, a mineral potential assessment using a subset of the Atlas has been undertaken for carbonatite-related rare earth element mineral systems that aims to support mineral exploration and land-use decision making that aims to support mineral exploration and land-use decision making.</div>

This Record documents the efforts of Mineral Resources Tasmania (MRT) and Geoscience Australia (GA) in compiling a geochronology (age) compilation for Tasmania, describing both the dataset itself and the process by which it is incorporated into the continental-scale Isotopic Atlas of Australia. The Isotopic Atlas draws together age and isotopic data from across the country and provides visualisations and tools to enable non-experts to extract maximum value from these datasets. Data is added to the Isotopic Atlas in a staged approach with priorities determined by GA- and partner-driven focus regions and research questions. This Tasmanian compilation represents the second in a series of compilation publications (Records and Datasets) for the southern states of Australia, which are a foundation for the second phase of the Exploring for the Future initiative over 2020–2024. It was compiled primarily from data, reports, journal articles and theses provided to GA by MRT. The most current data can be accessed and downloaded from GA’s <a href=https://portal.ga.gov.au/persona/geochronology>EFTF Geochronology and Isotopes Data Portal</a> and MRT’s <a href=https://www.mrt.tas.gov.au/mrt_maps/app/list/map>LISTmap.</a>

<div>The mineral potential toolkit (aka minpot-toolkit) provides tools to facilitate mineral potential analysis, from spatial associations to feature engineering and fully integrated mineral potential mapping.</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 thought 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 Earths 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.&nbsp;</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. They are also directly related to metallogenesis and mineralisation, particularly for a number of the critical minerals, e.g., rare earth elements, niobium. In light of this, Geoscience Australia is undertaking a compilation of the distribution and geology of Australian alkaline and related rocks, of all ages, and producing a GIS and associated database of such rocks, to both document such rocks and for use in metallogenic and mineral potential studies.</div><div><br></div><div>This contribution presents data on the distribution and geology of Australian alkaline and related rocks of Cenozoic 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.</div><div><br></div><div>Cenozoic alkaline and related rocks occur primarily within a belt running from Northeastern Queensland, through eastern New South Wales into Victoria and through to South Australia and Tasmania with a single occurrence in Western Australia. Compositions range from peralkaline trachytic and rhyolitic rocks to lamprophyric rocks to alkali basalts and more undersaturated feldspathoid-bearing lithologies. Ages span the entire Cenozoic but locally and regionally are more restrictive. Bodies are generally of small volume (extrusive rocks) or of small size (intrusive rocks). On the basis of location (and lithology, age and/or alkaline classification), 332 individual geologic units have been grouped into 59 informal alkaline provinces. The latter provides a simplified broad-scale overview of the distribution of the Cenozoic alkaline and related rocks of Australia but also allows for better search capabilities at broad scales in the GIS environment (overcoming the small size of many alkaline bodies).</div>

<div>The Exploring for the Future program (EFTF) is a $225M Federal Government-funded initiative spanning the period July 2016 to June 2024. This multi-disciplinary program involves aspects of method development and new pre-competitive data acquisition at a variety of scales, with the aim of building an integrated understanding of Australia’s mineral, energy and groundwater potential. Significant work has been undertaken across northern Australia within regional-scale projects and as part of national-scale data acquisition and mapping activities. Some of these activities have been largely completed, and have generated new data and products, while others are ongoing. A comprehensive overview of the EFTF program can be found via the program website (eftf.ga.gov.au). Here, we overview a range of activities with implications for resource exploration in the Northern Territory.</div><div><br></div>This Abstract was submitted & presented to the 2023 Annual Geoscience Exploration Seminar (AGES), Alice Springs (https://industry.nt.gov.au/news/2022/december/registrations-open-for-ages-2023)

<div>Maps showing the potential for carbonatite-related rare earth element (REE) mineral systems in Australia. Each of the mineral potential maps is a synthesis of three or four component layers. Model 1 integrates three components: sources of metals, energy drivers, and lithospheric architecture. Model 2 integrates four components: sources of metals, energy drivers, lithospheric architecture, and ore deposition. Both models use a hybrid data-driven and knowledge driven methodology to produce the final mineral potential map for the mineral system. An uncertainty map is provided in conjunction with the mineral potential map for Model 2 that represents the availability of data coverage over Australia for the selected combination of input maps. Uncertainty values range between 0 and 1, with higher uncertainty values being located in areas where more input maps are missing data or have unknown values. An assessment criteria table is provided and contains information on the map creation.</div>

<div>Mineral exploration and development involves the selection of potential projects which must be evaluated across disparate characteristics. However, the distinct metrics involved are typically difficult to reconcile (e.g. geological potential, environmental impact, jobs created, value generated, etc.). Separate stakeholders—with different goals and attitudes—will reasonably differ in their preferences as to which categories to prioritize and how much weight to give to each. These conflicting preferences can obscure optimal outcomes and confound project selection.</div><div><br></div><div>In this presentation, we will discuss how early-stage exploration decisions can be treated as multi-criteria optimization problems. We show how this approach can be used to effectively evaluate and communicate competing criteria, and locate regions that perform best under a range of different metrics. We then outline a mapping framework that identifies regions that perform best in terms of geological potential, economic value and environmental impact and demonstrate this approach in a real-word example that highlights new exploration targets in the Australian context. Abstract presented at the American Geophysical Union (AGU) Fall Meeting 2023 (AGU23) https://www.agu.org/fall-meeting

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>Sediment-hosted copper (Cu) mineral systems are important sources of base metals and critical minerals such as cobalt that are vital to delivering Australia’s low-carbon economy. In Australia, sediment-hosted Cu resources account for ~11% of the total Cu resources. Given their significance to the Australian economy, national-scale mineral potential models for sediment-hosted Cu have been developed. In addition to the potential for sediment-hosted Cu mineralisation, the uncertainty related to data availability has been examined. Three mineral potential</div><div>models derived from the combination of two mineral systems have been derived from a large volume of precompetitive geoscience data combined with mineral systems expertise, each using a different combination of input maps to assess the influence of incomplete data on the results. The mineral potential models successfully predict the location of major sediment-hosted stratiform Cu and Mount Isa-type Cu deposits while highlighting new areas of elevated prospectivity in under-explored regions of Australia, reducing the exploration search space</div><div>by up to ~84%.</div>

<div>Australian sediment-hosted mineral systems are important sources of base metals and critical minerals that are vital to delivering Australia’s low-carbon economy. In Australia, sediment-hosted resources account for ~82% and ~86% of the total zinc (Zn) and lead (Pb) resources respectively. Given their significance to the Australian economy, four national-scale mineral potential models for sediment-hosted Zn-Pb mineral systems have been developed: clastic-dominated siliciclastic carbonate, clastic-dominated siliciclastic mafic, Mississippi Valley-type and Irish-type. In addition to the potential for Zn-Pb mineralisation, the uncertainty related to data availability has been examined. The mineral potential models were created using a mineral systems-based approach where mappable criteria have been used to assess the prospectivity of each system. Each model has been derived from a large volume of precompetitive geoscience data. The clastic-dominated siliciclastic carbonate mineral potential model predicts 92% of known deposits and occurrences within 15.5% of the area, the clastic-dominated siliciclastic mafic mineral potential model predicts 85% of deposits and occurrences within 27% of the area, and the Mississippi Valley-type mineral potential model predicts 66% of known deposits and occurrences within 31% of the area. Each model successfully predict the location of major sediment-hosted Zn-Pb deposits while highlighting new areas of elevated prospectivity in under-explored regions of Australia, reducing the exploration search space by up to 85% for sediment-hosted Zn-Pb mineral systems.</div>