The Box Hole Pb-Zn (MVT) deposit – Georgina Basin, NT

Historical company data provide a valuable resource for additional processing of data and data integration. The Box Hole deposit is an example of using geochemistry, lithology, structural data, and geophysics to create a 3D model.

The Box Hole Pb-Zn (MVT) deposit is situated in the southern Georgina Basin in Central Australia within the shallow subtidal to peritidal Cambrian Arrinthrunga Formation. The outcropping stratabound mineralisation occurs as isolated galena cubes in dolostone, as breccia infill, interstices in silicified stromatolitic dolostone, and as galena veins. Alteration assemblages as part of the mineralising system include barite replacement, silicification and dolomitisation.

The project (2021) was aimed to re-process legacy data and building a 3D model of the deposit. Specific focus was the integration and harmonisation of lithology, geochemistry, geophysics in a structural 3D model towards improved exploration targeting.

The main new results of the project were the identification of two stratabound mineralising horizons within or near interbedded siliciclastic rocks and dolostones. Pervasive alteration (Ba, Mn, Sr) of dolostones and limestones occurs mostly within proximity to mineralisation. The geophysical data inversion (VTEM, gravity and magnetics) commonly maps variations in lithology and structures. The structural interpretation revealed multiple deformation events, including gently folding of strata and fault reactivation.