<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>

Northern Australia contains extensive Proterozoic aged sedimentary basins that contain organic-rich rocks with the potential to host major petroleum and basin-hosted mineral systems (Figures 1 and 2). These intracratonic basins include the greater McArthur Basin including the McArthur and Birrindudu basins and the Tomkinson Provence (Close 2014), the Isa Superbasin and the South Nicholson Basin. The sedimentary sections within these basins are assumed to be of equivalent age and deposited under similar climatic controls resulting in correlative lithology, source facies and stratigraphic intervals. The greater McArthur Basin contains Paleoproterozoic to Mesoproterozoic organic-rich siltstones and shales with the potential to generate conventional oil and gas deposits, self-sourced continuous shale oil and shale gas targets (Munson 2014; Revie 2017; Weatherford Laboratories 2017). Exploration has focused on the Beetaloo Sub-basin where organic-rich siltstones of the Velkerri Formation contain up to 10 weight percent total organic carbon (wt % TOC) and have been assessed to contain 118 trillion cubic feet (Tcf) of gas-in-place (Munson 2014; Revie 2017; Weatherford Laboratories 2017; Revie and Normington 2018). Other significant source rocks include the Kyalla Formation of the Roper Group, the Barney Creek, Yalco and Lynott formations of the McArthur Group, the Wollogorang, and perhaps the McDermott formations of the Tawallah Group and the Vaughton Siltstone of the Balma Group in the northern greater McArthur Basin (Munson 2014). These source rocks are host to diverse play types, for example, Cote et al (2018) describes five petroleum plays in the Beetaloo Sub-basin; the Velkerri shale dry gas play, the Velkerri liquids-rich gas play, the Kyalla shale and hybrid liquid-rich gas play and the Hayfield Sandstone oil/condensate play. This highlights the large shale and tight gas resource potential of the McArthur Basin, the full extent of these resources are poorly understood and insufficiently quantified. More work is needed to characterise the source rocks, the petroleum generative potential, fluid migration pathways, the fluid types and the thermal and burial history to understand the hydrocarbon prospectivity of the basin. The Exploring for the Future (EFTF) program is a four-year (2016?-2020) $100.5 million initiative by the Australian Government conducted in partnership with state and Northern Territory government agencies, other key government, research and industry partners and universities. EFTF aims to boost northern Australia's attractiveness as a destination for investment in resource exploration. The Energy Systems Branch at Geoscience Australia has undertaken a regional study on the prospectivity of several northern Australian basins by expanding our knowledge of petroleum and mineral system geochemistry. Here we highlight some of the results of this ongoing program with a primary focus on the greater McArthur Basin. Abstract submitted to and presented at the Annual Geoscience Exploration Seminar (AGES) 2019 (https://www.aig.org.au/events/ages-2019/)