Resourcing the Territory (2018-2022)

NTGS geophysical acquisition programs between 2018-2022:

• NTGS Brunette Downs Ground Gravity Survey was acquired in 2022 and was managed by Geoscience Australia. The survey covers an area of around 57,000 square kilometres located just north of Tennant Creek and extending to the Northern Territory - Queensland border. The survey infills existing 4 km gravity coverage to 2 km coverage. NTGS partnered with industry to acquire higher resolution data at 1 km x 1 km and 500 m x 500 m spacing over smaller areas within the survey. The data package consist of 17 312  gravity stations as a point located dataset and grids of the newly acquired gravity data.
• NTGS Mount Peake – Crawford Airborne Magnetic and Radiometric Survey was acquired in 2019 and covers an area of approximately 22,000 square km. The survey is centred 250km NNE of Alice Springs and extends from the Tanami Region in the west to 40km east of the Barrow Creek township. Data was collected along 200m spaced north-south lines at 60m ground clearance. Industry partners are participating in this survey by funding infill data to 100m line spacing over areas of interest.
• NTGS Tanami Region Airborne Magnetic and Radiometric Survey was acquired in 2018 over more than 42,000 square km extending from the West Australian border to approximately 300km west of Tennant Creek. The survey was flown at 200m line spacing and more than 240,000 line km were acquired. Industry partners funded an additional 30,000 line km of infill data at 100m spacing.

New geoscience in the Barkly region

Between 2018-2022, the large volume of new geoscience data generated in the Barkly Tableland region led to a substantial increase in industry activity in greenfields areas. More than 17,000km² of new mineral exploration licence applications were made by industry over previous vacant ground in the Barkly Tableland east of Tennant Creek, targeting copper and gold. This area has not previously been explored for these minerals. Flagship NTGS releases include:

• Acquisition of the 813km Barkly seismic survey, and its integration with the interpreted data from the 2017 South Nicholson seismic survey.
• Release of the first Territory-wide SEEBASE, incorporating all the data acquired under EFTF GEMIS: Northern Territory SEEBASE and GIS.
• Acquisition of the Southwest McArthur Gravity survey, southeast of the Beetaloo Sub-basin.

NTGS data and publications between 2018-2022 from the Barkly Tableland can be found on the GEMIS website.

Greater McArthur Basin

• Release of a revised boundary and definition of the gas-rich Beetaloo Sub-basin on the basis of interpretation of industry seismic and well data by NTGS.
• Release of updates of the Territory’s shale resource dataset with new organic geochemistry data from both GA and NTGS.
• The 2017-2021 ARC Linkage Project, in collaboration with University of Adelaide, and industry and academic partners, focused on unravelling the tectonic palaeogeography of the greater McArthur Basin, including geochronology and isotopic studies to support regional correlations.

South Nicholson-Lawn Hill geoscience mapping

New regional-scale geological mapping by NTGS of outcropping geology in the Lawn Hill Platform and South Nicholson Basin, focussed on the Mount Drummond 1:250 000 sheet area integrating mapping with new geochronology and new seismic data acquired from Exploring for the Future.

Collaborative work between NTGS and Geoscience Australia has substantially upgraded the understanding the undercover distribution, basin geometry and resource potential of the subsurface South Nicholson Basin and Lawn Hill Platform, and their relationships to the Beetaloo Sub-basin and McArthur Basin.

Reinvigorating exploration in the Tennant Creek Region

New programs were designed by NTGS to reinvigorate exploration closer to Tennant Creek by increasing data accessibility and value-adding to historic exploration data:

• Compilation of digital mineral deposit atlases and 3D visualisation of mineral fields in the Tennant Creek area, in collaboration with the University of Queensland. The products for the Rover field southwest of Tennant Creek and the Tennant Creek mineral field are now complete.
• Compilation of open file industry gravity and aeromagnetic geophysical data over the Tennant Creek and Rover fields, including seamless merged high‑resolution grids
• Completion of digital capture of all historic drilling and geochemistry data from the Tennant Creek 1:250,000 geological mapsheet.
• Improving understanding of the geological framework and gold and base metal potential of the concealed Rover field through acquiring new data from drill core, in collaboration with GA.
• Developing a physical and virtual repository of representative drill core from the Tennant Creek and Rover fields utilising the HyLogger^TM to provide spectral information on key drill core.

NTGS Data and publications between 2018-2022 from the Tennant Region can be found on the GEMIS website.

Aileron and Irindina provinces

Between 2018-2022, NTGS focused on Geoscience outcrop mapping at 1:250 000 and 1:100 000 across the north eastern Aileron and Irindina provinces provided an updated geological framework to these polymetallic provinces. This updated framework is designed to provide context to a new understanding of the geology and base metals potential of the Aileron Province, including studies of copper-bearing mineral systems in the region.

Outputs across the Aileron and Irindina provinces:

• Release of the Jervois Range Special 1:100,000 scale geological map and explanatory notes in 2019.
• Ongoing geoscience outcrop mapping at 1:100 000 scale across the northeastern Aileron Province
• Release of products on the mineral deposits and potential of copper and tungsten mineral systems across the Aileron Province, including stable isotope and geochronology studies.

NTGS data and publications [2018-2022] on the Aileron and Irindina provinces can be discovered on the GEMIS website.

Amadeus Basin

Outcrop mapping was also undertaken at 1:250 000 and 1:100 000 across the central and western Amadeus Basin providing consistent basin-wide stratigraphic correlation and improving the understanding of stratigraphy, structural evolution and palaeogeography. Basin-wide 1:500 000 pre-Mesozoic interpretative geology map was produced through the integration of the seamless stratigraphic approach with regional scale geophysics.

Outputs across the Amadeus Basin:

• Release of the Western Amadeus Basin 1:500 000 seamless interpreted geology map (pre-Mesozoic) and accompanying explanatory notes in 2021.
• Revision of the Neoproterozoic to early Cambrian stratigraphic framework of the basin
• Completion of mapping the Henbury 1:250,000 and Henbury Special 1:100,000 sheets, with map linework complete
• Helicopter-supported mapping of the Lake Amadeus and Bloods Range 1:250,000 sheets, completed during the 2019 field season.

NTGS data and publications [2018-2022] on the Amadeus Basin can be discovered on the GEMIS website.