Geochemical surveys deliver fundamental data, information and knowledge about the concentration and spatial distribution of chemical elements, isotopes and compounds in the natural environment. Typically near-surface sampling media, such as soil, sediment, outcropping rocks and stream or groundwater, are used. The application of such datasets to fields such as mineral exploration, environmental management, and geomedicine has been widely documented. In this presentation I reflect on a sabbatical experience with the Australian Federal Police (AFP) in 2017-2018 that allowed me to extend the interpretation of geochemical survey data beyond these established applications. In particular, with my collaborators we explore ways in which geochemical survey data and maps can be used to indicate the provenance of an evidentiary sample collected at a crime scene or obtained for instance from items belonging to a suspect intercepted at border entry. Because soils are extremely diverse mineralogically, geochemically and biologically, it should theoretically be possible to exclude very large swathes of territory (>90%) from further provenancing investigation using soil data. In a collaboration between Geoscience Australia (GA), the AFP and the University of Canberra (UC), a recent geochemical survey of the urban/suburban Canberra region in southeastern Australia is being used as a testbed for developing different approaches to forensic applications of geochemical surveys. A predictive soil provenancing method at the national scale was also developed and tested for application where no actual detailed, fit-for-purpose geochemical survey data exist. Over the next few years, GA, AFP and UC are collaborating with Flinders University to add biome data from soil and soil-derived dust to further improve the provenancing technique. This Abstract was presented at the 2021 Goldschmidt Conference (https://conf.goldschmidt.info/goldschmidt/2021/meetingapp.cgi)

We collected 38 groundwater and two surface water samples in the semi-arid Lake Woods region of the Northern Territory to better understand the hydrogeochemistry of this system, which straddles the Wiso, Tennant Creek and Georgina geological regions. Lake Woods is presently a losing waterbody feeding the underlying groundwater system. The main aquifers comprise mainly carbonate (limestone and dolostone), siliciclastic (sandstone and siltstone) and evaporitic units. The water composition was determined in terms of bulk properties (pH, electrical conductivity, temperature, dissolved oxygen, redox potential), 40 major, minor and trace elements as well as six isotopes (δ18Owater, δ2Hwater, δ13CDIC, δ34SSO4=, δ18OSO4=, 87Sr/86Sr). The groundwater is recharged through infiltration in the catchment from monsoonal rainfall (annual average rainfall ~600 mm) and runoff. It evolves geochemically mainly through evapotranspiration and water–mineral interaction (dissolution of carbonates, silicates, and to a lesser extent sulfates). The two surface waters (one from the main creek feeding the lake, the other from the lake itself) are extraordinarily enriched in 18O and 2H isotopes (δ18O of +10.9 and +16.4 ‰ VSMOW, and δ2H of +41 and +93 ‰ VSMOW, respectively), which is interpreted to reflect evaporation during the dry season (annual average evaporation ~3000 mm) under low humidity conditions (annual average relative humidity ~40 %). This interpretation is supported by modelling results. The potassium (K) relative enrichment (K/Cl mass ratio over 50 times that of sea water) is similar to that observed in salt-lake systems worldwide that are prospective for potash resources. Potassium enrichment is believed to derive partly from dust during atmospheric transport/deposition, but mostly from weathering of K-silicates in the aquifer materials (and possibly underlying formations). Further studies of Australian salt-lake systems are required to reach evidence-based conclusions on their mineral potential for potash, lithium, boron and other low-temperature mineral system commodities such as uranium. <b>Citation:</b> P. de Caritat, E. N. Bastrakov, S. Jaireth, P. M. English, J. D. A. Clarke, T. P. Mernagh, A. S. Wygralak, H. E. Dulfer & J. Trafford (2019) Groundwater geochemistry, hydrogeology and potash mineral potential of the Lake Woods region, Northern Territory, Australia, <i>Australian Journal of Earth Sciences</i>, 66:3, 411-430, DOI: 10.1080/08120099.2018.1543208

The Historical Bushfire Boundaries service represents the aggregation of jurisdictional supplied burnt areas polygons stemming from the early 1900's through to 2022 (excluding the Northern Territory). The burnt area data represents curated jurisdictional owned polygons of both bushfires and prescribed (planned) burns. To ensure the dataset adhered to the nationally approved and agreed data dictionary for fire history Geoscience Australia had to modify some of the attributes presented. The information provided within this service is reflective only of data supplied by participating authoritative agencies and may or may not represent all fire history within a state.

This brochure gives an overview of Geoscience Australia's priority programs: Exploring for the Future, Digital Earth Australia and Positioning Australia;

This map is part of the AUSTopo - Australian Digital Topographic Map Series. It covers the whole of Australia at a scale of 1:250 000 (1cm on a map represents 2.5 km on the ground) and comprises 516 maps. This is the largest scale at which published topographic maps cover the entire continent. Each standard map covers an area of approximately 1.5 degrees longitude by 1 degree latitude or about 150 kilometres from east to west and at least 110 kilometres from north to south. The topographic map shows approximate coverage of the sheets. The map may contain information from surrounding map sheets to maximise utilisation of available space on the map sheet. There are about 50 special maps in the series and these maps cover a non-standard area. Typically, where a map produced on standard sheet lines is largely ocean it is combined with its landward neighbour. These maps contain natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 50m), localities and some administrative boundaries. Coordinates: Geographical and MGA Datum: GDA94, GDA2020, AHD. Projection: Universal Traverse Mercator (UTM) Medium: Digital PDF download.

This map is part of the AUSTopo - Australian Digital Topographic Map Series. It covers the whole of Australia at a scale of 1:250 000 (1cm on a map represents 2.5 km on the ground) and comprises 516 maps. This is the largest scale at which published topographic maps cover the entire continent. Each standard map covers an area of approximately 1.5 degrees longitude by 1 degree latitude or about 150 kilometres from east to west and at least 110 kilometres from north to south. The topographic map shows approximate coverage of the sheets. The map may contain information from surrounding map sheets to maximise utilisation of available space on the map sheet. There are about 50 special maps in the series and these maps cover a non-standard area. Typically, where a map produced on standard sheet lines is largely ocean it is combined with its landward neighbour. These maps contain natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 50m), localities and some administrative boundaries. Coordinates: Geographical and MGA Datum: GDA94, GDA2020, AHD. Projection: Universal Traverse Mercator (UTM) Medium: Digital PDF download.

This map is part of the AUSTopo - Australian Digital Topographic Map Series. It covers the whole of Australia at a scale of 1:250 000 (1cm on a map represents 2.5 km on the ground) and comprises 516 maps. This is the largest scale at which published topographic maps cover the entire continent. Each standard map covers an area of approximately 1.5 degrees longitude by 1 degree latitude or about 150 kilometres from east to west and at least 110 kilometres from north to south. The topographic map shows approximate coverage of the sheets. The map may contain information from surrounding map sheets to maximise utilisation of available space on the map sheet. There are about 50 special maps in the series and these maps cover a non-standard area. Typically, where a map produced on standard sheet lines is largely ocean it is combined with its landward neighbour. These maps contain natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 50m), localities and some administrative boundaries. Coordinates: Geographical and MGA Datum: GDA94, GDA2020, AHD. Projection: Universal Traverse Mercator (UTM) Medium: Digital PDF download.

This map is part of the AUSTopo - Australian Digital Topographic Map Series. It covers the whole of Australia at a scale of 1:250 000 (1cm on a map represents 2.5 km on the ground) and comprises 516 maps. This is the largest scale at which published topographic maps cover the entire continent. Each standard map covers an area of approximately 1.5 degrees longitude by 1 degree latitude or about 150 kilometres from east to west and at least 110 kilometres from north to south. The topographic map shows approximate coverage of the sheets. The map may contain information from surrounding map sheets to maximise utilisation of available space on the map sheet. There are about 50 special maps in the series and these maps cover a non-standard area. Typically, where a map produced on standard sheet lines is largely ocean it is combined with its landward neighbour. These maps contain natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 50m), localities and some administrative boundaries. Coordinates: Geographical and MGA Datum: GDA94, GDA2020, AHD. Projection: Universal Traverse Mercator (UTM) Medium: Digital PDF download.

This map is part of the AUSTopo - Australian Digital Topographic Map Series. It covers the whole of Australia at a scale of 1:250 000 (1cm on a map represents 2.5 km on the ground) and comprises 516 maps. This is the largest scale at which published topographic maps cover the entire continent. Each standard map covers an area of approximately 1.5 degrees longitude by 1 degree latitude or about 150 kilometres from east to west and at least 110 kilometres from north to south. The topographic map shows approximate coverage of the sheets. The map may contain information from surrounding map sheets to maximise utilisation of available space on the map sheet. There are about 50 special maps in the series and these maps cover a non-standard area. Typically, where a map produced on standard sheet lines is largely ocean it is combined with its landward neighbour. These maps contain natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 50m), localities and some administrative boundaries. Coordinates: Geographical and MGA Datum: GDA94, GDA2020, AHD. Projection: Universal Traverse Mercator (UTM) Medium: Digital PDF download.

This map is part of the AUSTopo - Australian Digital Topographic Map Series. It covers the whole of Australia at a scale of 1:250 000 (1cm on a map represents 2.5 km on the ground) and comprises 516 maps. This is the largest scale at which published topographic maps cover the entire continent. Each standard map covers an area of approximately 1.5 degrees longitude by 1 degree latitude or about 150 kilometres from east to west and at least 110 kilometres from north to south. The topographic map shows approximate coverage of the sheets. The map may contain information from surrounding map sheets to maximise utilisation of available space on the map sheet. There are about 50 special maps in the series and these maps cover a non-standard area. Typically, where a map produced on standard sheet lines is largely ocean it is combined with its landward neighbour. These maps contain natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 50m), localities and some administrative boundaries. Coordinates: Geographical and MGA Datum: GDA94, GDA2020, AHD. Projection: Universal Traverse Mercator (UTM) Medium: Digital PDF download.