<div>The Proterozoic alkaline and related igneous rocks of Australia is a surface geology compilation of alkaline and related igneous rocks of Proterozoic age in Australia. This dataset is one of five datasets, with compilations for Archean, Paleozoic, Mesozoic and Cenozoic alkaline and related igneous rocks already released.</div><div><br></div><div>Geological units are represented as polygon and point geometries and, are attributed with information that includes, but is not limited to, stratigraphic nomenclature and hierarchy, age, lithology, composition, proportion of alkaline rocks, body morphology, unit expression, emplacement type, presence of mantle xenoliths and diamonds, and primary data source. Source data for the geological unit polygons provided in Data Quality LINEAGE. Geological units are grouped into informal geographic “alkaline provinces”, which are represented as polygon geometries, and attributed with information similar to that provided for the geological units.</div>

<div>This data package contains interpretations of airborne electromagnetic (AEM) conductivity sections in the Exploring for the Future (EFTF) program’s Eastern Resources Corridor (ERC) study area, in south eastern Australia. Conductivity sections from 3 AEM surveys were interpreted to provide a continuous interpretation across the study area – the EFTF AusAEM ERC (Ley-Cooper, 2021), the Frome Embayment TEMPEST (Costelloe et al., 2012) and the MinEx CRC Mundi (Brodie, 2021) AEM surveys. Selected lines from the Frome Embayment TEMPEST and MinEx CRC Mundi surveys were chosen for interpretation to align with the 20&nbsp;km line-spaced EFTF AusAEM ERC survey (Figure 1).</div><div>The aim of this study was to interpret the AEM conductivity sections to develop a regional understanding of the near-surface stratigraphy and structural architecture. To ensure that the interpretations took into account the local geological features, the AEM conductivity sections were integrated and interpreted with other geological and geophysical datasets, such as boreholes, potential fields, surface and basement geology maps, and seismic interpretations. This approach provides a near-surface fundamental regional geological framework to support more detailed investigations. </div><div>This study interpreted between the ground surface and 500&nbsp;m depth along almost 30,000 line kilometres of nominally 20&nbsp;km line-spaced AEM conductivity sections, across an area of approximately 550,000&nbsp;km2. These interpretations delineate the geo-electrical features that correspond to major chronostratigraphic boundaries, and capture detailed stratigraphic information associated with these boundaries. These interpretations produced approximately 170,000 depth estimate points or approximately 9,100 3D line segments, each attributed with high-quality geometric, stratigraphic, and ancillary data. The depth estimate points are formatted for compliance with Geoscience Australia’s (GA) Estimates of Geological and Geophysical Surfaces (EGGS) database, the national repository for standardised depth estimate points. </div><div>Results from these interpretations provided support to stratigraphic drillhole targeting, as part of the Delamerian Margins NSW National Drilling Initiative campaign, a collaboration between GA’s EFTF program, the MinEx CRC National Drilling Initiative and the Geological Survey of New South Wales. The interpretations have applications in a wide range of disciplines, such as mineral, energy and groundwater resource exploration, environmental management, subsurface mapping, tectonic evolution studies, and cover thickness, prospectivity, and economic modelling. It is anticipated that these interpretations will benefit government, industry and academia with interest in the geology of the ERC region.</div>

<div>The National Geochemical Survey of Australia (NGSA) is Australia’s only internally consistent, continental-scale geochemical atlas and dataset. The present report presents additional mineralogical data acquired as part of the Heavy Mineral Map of Australia (HMMA) project on the NGSA samples, covering ~81% of Australia. The HMMA project, a collaborative project between Geoscience Australia and Curtin University underpinned by a pilot project establishing its feasibility, is part of the Australian Government-funded Exploring for the Future (EFTF) program.</div><div>All of the 1315 NGSA bottom catchment outlet sediment samples, taken on average from 60 to 80 cm depth in floodplain landforms, were used in the HMMA project. The samples were dried and sieved to a 75-425 µm grainsize fraction, and the contained heavy minerals (HMs; i.e., those with a specific gravity > 2.9 g/cm3) were separated by dense fluids and mounted on cylindrical epoxy mounts. After polishing and carbon-coating, the mounts were subjected to automated mineralogical analysis on a TESCAN® Integrated Mineral Analyzer (TIMA). Using scanning electron microscopy and backscatter electron imaging integrated with energy dispersive X-ray analysis, the TIMA identified 163 unique phases (including ‘Unclassified”) in the NGSA sample set. The dataset, consisting of over 145 million individual mineral grains, was quality controlled and validated by an expert team. The data released here can be visualised, explored and downloaded using a free online, bespoke mineral network analysis (MNA) tool built on a cloud-based platform. Preliminary analysis suggests that zinc minerals and native elements&nbsp;(e.g., native gold and platinum) may be useful in mineral exploration applications. Detailed interpretations of the HMMA dataset will be provided elsewhere. Accompanying this report are data files of TIMA results, a minerals property file, and an atlas of HM distribution maps. </div><div>It is hoped the comprehensive dataset generated by the HMMA project will be of use to mineral exploration and prospectivity modelling around Australia, as well as have other applications in earth and environmental sciences.</div>

<div>The interpretation of AusAEM airborne electromagnetic (AEM) survey conductivity sections in the Canning Basin region delineates the geo-electrical features that correspond to major chronostratigraphic boundaries, and captures detailed stratigraphic information associated with these boundaries. This interpretation forms part of an assessment of the underground hydrogen storage potential of salt features in the Canning Basin region based on integration and interpretation of AEM and other geological and geophysical datasets. A main aim of this work was to interpret the AEM to develop a regional understanding of the near-surface stratigraphy and structural geology. This regional geological framework was complimented by the identification and assessment of possible near-surface salt-related structures, as underground salt bodies have been identified as potential underground hydrogen storage sites. This study interpreted over 20,000 line kilometres of 20&nbsp;km nominally line-spaced AusAEM conductivity sections, covering an area approximately 450,000 km2 to a depth of approximately 500&nbsp;m in northwest Western Australia. These conductivity sections were integrated and interpreted with other geological and geophysical datasets, such as boreholes, potential fields, surface and basement geology maps, and seismic interpretations. This interpretation produced approximately 110,000 depth estimate points or 4,000 3D line segments, each attributed with high-quality geometric, stratigraphic, and ancillary data. The depth estimate points are formatted for Geoscience Australia’s Estimates of Geological and Geophysical Surfaces database, the national repository for formatted depth estimate points. Despite these interpretations being collected to support exploration of salt features for hydrogen storage, they are also intended for use in a wide range of other disciplines, such as mineral, energy and groundwater resource exploration, environmental management, subsurface mapping, tectonic evolution studies, and cover thickness, prospectivity, and economic modelling. Therefore, these interpretations will benefit government, industry and academia interested in the geology of the Canning Basin region.</div>

The National Geochemical Survey of Australia (NGSA) is Australia’s only internally consistent, continental-scale geochemical atlas and dataset (<a href="http://dx.doi.org/10.11636/Record.2011.020">http://dx.doi.org/10.11636/Record.2011.020</a>). The present dataset provides additional geochemical data for Li, Be, Cs, and Rb acquired as part of the Australian Government-funded Exploring for the Future (EFTF) program and in support of the Australian Government’s 2023-2030 Critical Minerals Strategy. The dataset fills a knowledge gap about Li distribution in Australia over areas dominated by transported regolith. The main ‘total’ element analysis method deployed for NGSA was based on making a fused bead using lithium-borate flux for XRF then ICP-MS analysis. Consequently, the samples could not be meaningfully analysed for Li. All 1315 NGSA milled coarse-fraction (<2 mm) top (“TOS”) catchment outlet sediment samples, taken from 0 to 10 cm depth in floodplain landforms, were analysed in the current project following the digestion method that provides near-total concentrations of Li, Be, Cs, and Rb. The samples were analysed by the commercial laboratory analysis service provider Bureau Veritas in Perth using low-level mixed acid (a mixture of nitric, perchloric and hydrofluoric acids) digestion with elements determined by ICP-MS (Bureau Veritas methods MA110 and MA112). The data are reported in the same format as the NGSA dataset, allowing for seamless integration with previously released NGSA data. Further details on the QA/QC procedures as well as data interpretation will be reported elsewhere. This data release also includes four continental-scale geochemical maps for Li, Be, Cs, and Rb built from these analytical data. This dataset, in conjunction with previous data published by NGSA, will be of use to mineral exploration and prospectivity modelling around Australia by providing geochemical baselines for Li, Be, Cs, and Rb, as well as identifying regions of anomalism. Additionally, these data also have relevance to other applications in earth and environmental sciences.

<div>Quality assurance and quality control (QAQC) of geochemical data is an important first step before any interpretation of the data is undertaken. Due to the increasing number of elements that are being reported by laboratories undertaking multi-element analysis, the time to undertake QAQC of the data has increased. In order to alleviate the increasing time constraints of undertaking QAQC this python script was developed. This script provides a quick first pass of the data automatically to produce summary statistics and plots of the included standards laboratory duplicates and analytical duplicates. The statistics and plots allow for rapid assessment of geochemical data to discover potential issues with the data and trends though time, whilst also providing a consistent approach. It should be noted that no general quality cut-offs have been included within the script as it does not replace the need for an expert examining the data to identify potential issues.</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 contribution presents data on the distribution and geology of Australian alkaline and related rocks of Proterozoic age. Proterozoic alkaline and related rocks are primarily restricted to the western two-thirds of the Australia continent, congruent with the distribution of Proterozoic rocks more generally. Proterozoic alkaline rock units are most abundant in Western Australia and the Northern Territory, with minor occurrences in South Australia, and the western regions of Queensland, New South Wales and Tasmania.</div><div><br></div><div>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.&nbsp;</div>

<div>The ‘Major crustal boundaries of Australia’ data set synthesises more than 40 years of acquisition of deep seismic reflection data across Australia, where major crustal-scale breaks, often inferred to be relict sutures between different crustal blocks, have been interpreted in the seismic reflection profiles. The widespread coverage of the seismic profiles now provides the opportunity to construct a map of major crustal boundaries across Australia. Starting with the locations of the crustal breaks identified in the seismic profiles, geological (e.g. outcrop mapping, drill hole, geochronology, isotope) and geophysical (e.g. gravity, aeromagnetic, magnetotelluric, passive seismic) data are used to map the crustal boundaries, in map view, away from the seismic profiles. For some of these boundaries, a high level of confidence can be placed on the location, whereas the location of other boundaries can only be considered to have medium or low confidence. In other areas, especially in regions covered by thick sedimentary successions, the locations of some crustal boundaries are essentially unconstrained. </div><div>The ‘Major crustal boundaries of Australia’ map shows the locations of inferred ancient plate boundaries, and will provide constraints on the three dimensional architecture of Australia. It allows a better understanding of how the Australian continent was constructed from the Mesoarchean through to the Phanerozoic, and how this evolution and these boundaries have controlled metallogenesis. It is best viewed as a dynamic dataset, which will need to be refined and updated as new information, such as new seismic reflection data, becomes available.</div><div><br></div>

<div>Geoscience Australia has a large holding of surface sediment samples, such as stream and overbank sediments, from geochemical surveys conducted over more than 50 years across the Australian continent. Geochemical data from these surface materials are of national importance as they can contribute significantly to establishing geochemical environmental baselines and their use in land management, as well as aiding in the discovery of new mineral deposits. Samples from these legacy surveys provide valuable insights into areas of Australia that are remote, difficult to access, or have since been developed. The age of a large number of these surveys, however, means that the original results included data for a&nbsp;smaller range of chemical elements, typically with poorer analytical precision and accuracy than those of modern surveys. This small range of chemical elements also typically doesn’t include important elements for modern use, such as critical minerals (i.e. Co, Bi, REEs), which are increasing in their importance. As part of Geoscience Australia’s Exploring for the Future program, a collection of over 9000 samples from these surveys was reanalysed using modern analytical techniques for a&nbsp;suite of 60 chemical elements. These samples cover several regions within Australia, including Kakadu, Cape York, the Mount Isa region, and near the Canberra region. The new analytical data maximise the value of the historical geochemical surveys and will provide new insights into the mineral potential of these regions and improve the quality of geochemical environmental baselines.&nbsp;</div><div><br></div><div>This data release includes: 1) information on the surveys and their samples; 2) quality assurance results; 3) a discussion of sample preparation and analytical methods used; 4) results for total content geochemistry (XRF and LA-ICP-MS); and 5) individual element maps for each of the regions for preliminary interpretation of the data.</div><div><br></div><div>Acquisition and release of this dataset forms part of a larger program aimed at creating a levelled geochemical baseline for the whole Australia (Main and Champion, 2020).</div>

<div>As part of the Australia's Resources Framework Project, in the Exploring for the Future Program, Geoscience Australia and CSIRO have undertaken a magnetic source depth study across four areas. These are: 1) the western part of Tasmania that is the southernmost extension of the Darling-Curnamona-Delamerian (DCD) project area; 2) northeastern Queensland; 3) the Officer Basin area of western South Australia and southeastern West Australia; and 4) the 'Eastern Resources Corridor' (ERC) covering eastern South Australia, southwest Queensland, western New South Wales and western Victoria. This study has produced 2005 magnetic estimates of depth to the top of magnetization. The solutions are derived by a consistent methodology (targeted magnetic inversion modelling, or TMIM; also known as ‘sweet-spot’ modelling). </div><div><br></div><div>The magnetic depth estimates produced as part of this study provide depth constraints in data-poor areas. They help to construct a better understanding of the 3D geometry of the Australian continent, and aid cover thickness modelling activities. </div><div><br></div><div>A supplementary interpretation data release is also available through Geoscience Australia's enterprise catalogue (ecat) at https://pid.geoscience.gov.au/dataset/ga/149499.</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. This work contributes to building a better understanding of the Australian continent, whilst giving the Australian public the tools they need to help them make informed decisions in their areas of interest.</div>