Towards a 3D model of the South-Nicholson Basin region, Northern Australia, for mineral, energy and groundwater assessment

The Exploring for the Future Program facilitated the acquisition of major geoscience datasets in northern Australia, where rocks are mostly under cover and the basin evolution, mineral, energy and groundwater resource potential are, in places, poorly constrained. In an effort to support sustainable, regional economic development and build stronger communities in these frontier areas, integration of new and legacy data within a consistent platform could enhance the recognition of cross-disciplinary synergies in sub-surface resource investigations. Here we present a case study in the South-Nicholson Basin, located in a poorly exposed area between the prospective Mt Isa Province and the McArthur Basin. Both regions host major base metal deposits, contain units prospective for energy resources, and hold significant groundwater resources in the overlying Georgina Basin. In this study, we interpret a subset of new regional-scale data, which include ~1 900 km of deep seismic reflection data and 60 000 line kilometres of AusAEM1 airborne electromagnetic survey, supplemented with legacy information. This interpretation refines a semi-continental geological framework, as input to national coverage databases and informs decision-making for exploration and groundwater resource management. This study provides a 3D chronostratigraphic cover model down to the Paleoproterozoic basement. We mapped the depth to the base of intervals corresponding to geological eras, as well as deeper pre-Neoproterozoic superbasin boundaries to refine the cover model. The depth estimates, based on the compilation, interpretation and integration of geological and geophysical datasets, inform the basement architecture controls on evolution of the basin, with several key outcomes: 1) expanded mapped size of the South Nicholson Basin, potentially, increasing prospectivity for hydrocarbons and basin-hosted mineralisation, 2) improved stratigraphic unit correlations across the region, 3) identification of major crustal structures, some of which are associated with mineralisation and springs, and 4) improved basin architecture definition, supporting future investigation of groundwater resources.