The GSQ Eulo 3 borehole was drilled approximately 50 km SW of Eulo, Queensland. The borehole was designed to test aeromagnetic anomalies in the basement rocks and to test the electrical conductivity properties of cover and basement rocks.

The GSQ Eulo 4 borehole was drilled approximately 35.5 km SW of Eulo, Queensland. The borehole was designed to test aeromagnetic anomalies in the basement rocks, and to test the electrical conductivity properties of cover and basement rocks to validate airborne electromagnetic (AEM) data.

The Milcarpa 1 borehole was drilled approximately 9 km SSE of Hungerford, Queensland, adjacent to the road between Hungerford and Wanaaring, NSW. The borehole was designed to test aeromagnetic anomalies in the basement rocks, test the electrical conductivity properties of cover and basement rocks to validate airborne electromagnetic (AEM) data, and to test pre-drilling geophysical cover thickness estimates.

The Tongo 1 borehole was drilled approximately 83 km NE of White Cliffs, New South Wales. The borehole was designed to test aeromagnetic anomalies in the basement rocks and to test the electrical conductivity properties of cover and basement rocks to validate airborne electromagnetic (AEM) data.

The Laurelvale 1 borehole was drilled approximately 78 km SSW of Wanaaring, New South Wales, adjacent to the through-road between Tongo and Tilpa. The borehole was designed to test the geology of indistinct, linear aeromagnetic anomalies in the basement rocks, test the electrical conductivity properties of cover and basement rocks to validate airborne electromagnetic (AEM) data, and to test pre-drilling geophysical cover thickness estimates.

The GSQ Cunnamulla 1 borehole was drilled approximately 110 km SE of Cunnamulla, Queensland. The borehole was designed to test aeromagnetic anomalies in the basement rocks, test the electrical conductivity properties of cover and basement rocks, and to test pre-drilling geophysical cover thickness estimates.

The Congararra 1 borehole was drilled approximately 70 km NNW of Bourke, NSW. The borehole was designed to test aeromagnetic anomalies in the basement rocks, test the electrical conductivity properties of cover and basement rocks to validate airborne electromagnetic (AEM) data, and to test pre-drilling geophysical cover thickness estimates.

<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.&nbsp;&nbsp;Exploring for the Future program, which commenced in 2016, is an eight year, $225m investment by the Australian Government.</div><div><br></div><div>The Proterozoic Birrindudu Basin is an underexplored region that contains sparse geological data. Strata of similar age are highly prospective to the east, in the McArthur and South Nicholson basins and the Mount Isa region. To investigate this underexplored and data-poor region, the L214 Northwest Northern Territory Seismic Survey was acquired in August to September 2023 by GA and co-funded by the Northern Territory Government. Prior to this survey the region contained minimal seismic data. To complement the acquisition of the seismic survey, a sampling program of legacy stratigraphic and mineral exploration drill holes was also undertaken.</div><div><br></div><div>The new sampling program and seismic reflection data acquired over the Birrindudu Basin and its flanks, has identified many areas of exploration opportunity. This has almost tripled seismic coverage over the Birrindudu Basin, which has enabled new perspectives to be gained on its geology and relationship to surrounding regions. The new seismic has shown an increase in the extent of the Birrindudu Basin, revealing the presence of extensive concealed Birrindudu Basin sedimentary sequences and major, well preserved depocentres. In the central Birrindudu Basin and Tanami Region, shallow basement and deep-seated faults are encouraging for mineralisation, as these structures have the potential to focus mineralised fluids to the near surface. The clear presence of shallow Tanami Region rocks underlying the southern Birrindudu Basin sequences at the northern end of line 23GA-NT2 extends the mineral resource potential of the Tanami Region further north into the southern Birrindudu Basin. A new minimum age of 1822±7 Ma for the deposition of metasediments in drill hole LBD2 for rocks underlying the central Birrindudu Basin, extends the age-equivalent mineral-rich basement rocks of the Tanami Region north into the central Birrindudu Basin – extending the mineral resource potential into a new region.</div><div><br></div><div>The continuous stratigraphy imaged of the Birrindudu Basin by the new seismic is encouraging for energy prospectivity, as the system elements needed for an effective petroleum system, better defined by the new sampling program results, have been imaged to extend over a wider and deeper area. New organic petrological analysis and reflectance data indicate the sampled sections have reached thermal maturity suitable for hydrocarbon generation. Oil inclusion analyses provide evidence for oil generation and migration, and hence elements of a petroleum system are present in the central and northwestern Birrindudu Basin. With the expanded breadth of these rocks demonstrated on the seismic, this greatly increases the spatial extent of hydrocarbon prospectivity in Birrindudu Basin.</div>

<div>Earth observation is a fast and cost-effective method for greenfields exploration of critical minerals at a continental to regional scale. A broad range of optical satellite sensors are now available to mineral explorers for collecting Earth observation information (EOI) at various spatial and spectral resolutions, with different capabilities for direct identification of mineral groups and/or species as well as selected chemical elements. The spectral resolution of many of the latest imaging spectroscopy satellite systems (e.g., PRISMA - https://www.asi.it/en/earth-science/prisma/; EnMap - https://www.enmap.org/; EMIT - https://earth.jpl.nasa.gov/emit/) allow the mapping of the relative mineral abundance and, in selected cases, even the chemical composition of hydrothermal alteration minerals and pegmatite indicator minerals, such as white mica, chlorite and tourmaline. More specialised hyperspectral satellite systems, such as DESIS (https://www.dlr.de/eoc/en/desktopdefault.aspx/tabid-13614/) feature a very high spectral resolution (235 bands at 2.55 nm sampling and 3.5 nm full width half maximum) across parts of the Visible to Near-Infrared (VNIR) wavelength range, opening up the possibility for direct mapping of rare earth elements, such as neodymium. The pixel size of the imaging spectroscopy satellite systems is commonly 30 m, which can be sufficient to map hydrothermal footprints of ore deposits or surface expressions of typical rare element host rocks, such as pegmatites and carbonatites. However, airborne hyperspectral surveys still provide a higher spatial resolution, which can be essential in a given mineral exploration campaign. Selected multispectral satellite systems, such as ASTER (https://terra.nasa.gov/data/aster-data) and WorldView3 (https://resources.maxar.com/data-sheets/worldview-3) do have bands at important wavelength ranges in the shortwave infrared, but not with high enough spectral resolution&nbsp;to clearly identify many indicator minerals for critical minerals deposits. Most publicly available satellite imagery comprises multispectral systems that are focussed on the VNIR, such as Landsat and Sentinel, but which allow the direct identification of only very few mineral groups (mainly iron oxides) and not hydroxylated vector minerals (e.g., white mica, chlorite, tourmaline). This work aims to provide a summary of currently available optical satellite sensors and high-level comparison of their applications for critical minerals exploration. In addition to the spatial and spectral resolution, the impact of, for example, signal-to-noise ratio, striping and band width on accurate mineral and element mapping is discussed. For this, case studies are presented that demonstrate the potential use of the respective sensors for different stages of an exploration campaign and also the opportunities for integration with other geoscience data across scales. This abstract was presented to the 13th IEEE GRSS Workshop on Hyperspectral Image and Signal Processing (WHISPERS) November 2023 (https://www.ieee-whispers.com/)

<div>The study utilised Geoscience Australia’s vast data collection of mineral occurrences to identify the range of historical discoveries within the Officer-Musgrave, Darling-Curnamona - Delameian and Barkly - Isa - Georgetown Deep Dive areas. A literature review shed light on exploration discovery methods, commodity grades, exploration histories and deposit types. Many critical mineral occurrences were overlooked or ignored in the past, as the commodity discovered was not of interest or value at the time, or grades were regarded as sub-economic. However, with modern methods of mining, ore treatment techniques and increased demand, reassessment could now provide new opportunities.</div>