Talk Description
The Birrindudu Basin is located in the north-western Northern Territory and comprises sedimentary successions of Palaeo-to Mesoproterozoic age. The basin overlies volcanic-sedimentary and magmatic rocks of the Tanami Region, Pine Creek Orogen, and parts of the Halls Creek Orogen. Multiple sedimentary packages occur in the basin: i) the Birrindudu Group located to the South of the basin with a maximum depositional age of 1,837-1,812 Ma; ii) the overlying Limbunya, Wattie, and Bullita groups in the central part of the basin with a maximum depositional age of 1,653-1,600 Ma. Our research aims at evaluating the potential of the basin for hosting sedimentary copper mineralisation by applying a mineral systems approach. Particular focus is on the palaeo-environmental evolution of the basin, the basin-basement interface, the identification of potential host/source rocks for copper, and favourable metal carriers and fluid pathways. Our preliminary results show that Palaeoproterozoic basalts and volcaniclastic units of the basement have been strongly leached by migrating fluids. Moreover, there is evidence for localised remobilisation of copper in a succession immediately below the basin-basement contact. The overlying Mesoproterozoic sandstones is highly porous/permeable and thus could have been a pathway for mineralising fluids. Evaporitic (anhydrite) dolostones and siliciclastic successions above the sandstone intervals could provide sulphur necessary for mineralisation. Further research is necessary to identify potential host rocks and the timing of fluid flow associated with metal transport.