Southern Northern Territory uranium and geothermal energy systems assessment digitial data package

Brief description

This dataset represents the results of the assessment of the potential for uranium and geothermal energy systems in the southern Northern Territory. Four uranium systems were targeted: 1) sandstone-hosted, 2) uranium-rich iron oxide-copper-gold, 3) unconformity-related, and 4) magmatic-related. These were assessed for using a 2D, GIS-based approach, and utilised a mineral systems framework. In addition to the uranium systems investigated, the potential for hot rock and hot sedimentary aquifer geothermal systems was also assessed. Only the results of the hot rock geothermal assessment are presented here, since the assessment for hot sedimentary aquifer geothermal systems is more qualitative in nature. The assessment for hot rock geothermal systems was undertaken in a 3D environment, with temperatures at depth predicted using the 3D GeoModeller software package.

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Maintenance and Update Frequency: notPlanned

Statement: Criteria for the uranium systems assessment were developed from geological, geochemical and geophysical data. Solid geology was compiled for the study area using existing solid geology datasets published by the Northern Territory Geological Survey, Geoscience Australia's 1:1 000 000 surface geology of Australia map and geophysical imagery. Additional information on the compilation of solid geology for the assessment is provided in the accompanying report. Geochemical data were compiled from Geoscience Australia's OZCHEM dataset (http://www.ga.gov.au/meta/ANZCW0703011055.html#distinfo), and were supplemented by a small number of samples from the Northern Territory Geological Survey's open-file geochemical dataset (accessed at http://geoscience.nt.gov.au/GeosambaU/strike_gs_webclient/default.aspx). Radiometric, magnetic and gravity data were also used to develop some criteria. These data were sourced from Geoscience Australia databases and are publicly available via the Geoscience Australia website. Derivative products of the input datasets were developed for the uranium assessments (e.g., buffering). Decisions concerning the development of these derivatives, such as the selection of buffer distances and assignment of cutoff values, were made subjectively based on the scientific judgement of the analyst. Further details of these are given in the respective sections of the accompanying report for each system. Hot rock geothermal prospectivity is derived from the modelled temperature at 4 km depth slice extracted from a 3D thermal model. The thermal modelling was performed using a 3D geological map constructed from geological and geophysical data to a depth of 15 km. The 3D map incorporates geological elements which were assigned heat-production and thermal-conductivity values. Thermal-conductivity values were assigned to each unit of the 3D map and were sourced from published measurements or estimated from lithological descriptions. Heat production was calculated using radiometric data sourced from Geoscience Australia and also assigned to the 3D map. Interpreted depth of sedimentary cover was determined using modelled depth to magnetic basement, seismic data and a digital elevation model sourced from Geoscience Australia.