THE ROLE OF AIRBORNE GEOPHYSICS IN FACILITATING LONG-TERM OUTBACK WATER SOLUTIONS TO SUPPORT MINING IN SOUTH AUSTRALIA

摘要

Mining and energy development in South Australia's far north is set to have significant consequences for the water resources of the region. These sectors generate significant economic value to the state and their support remains a priority for the government. The scale of the planned developments and the potential from current exploration programs facilitated by the South Australian Government's Plan for Accelerating Exploration (PACE) will result in an increase in infrastructure requirements, including access to water resources and Aboriginal lands for potential mine development.Increased demand for water and, in particular, groundwater, is compromised by the limited information we have about these resources. There is a recognised need to develop this knowledge so that water availability is not a limiting factor to development. The Goyder Institute's Long-Term Outback Water Solutions (G-FLOWS) Project was established to help address this. Particular reference is made to work completed in the Musgrave Province. It illustrates the role of local scale Airborne ElectroMagnetic surveys (AEM), acquired for exploration, and regional scale airborne magnetics and terrain data in helping develop a hydrogeological conceptual model for the Province.The AEM data reveal a complex and extensive inset palaeovalley system, which contains groundwater of variable quality (2000-4500 mg/L total dissolved solids (TDS)). Examination of their location against the regional magnetics indicates a strong litho-structural control on their orientation. If mineral resources were to be developed in the area, these groundwater systems would represent the best option for water supply.A regional scale water resource map, based on information gleaned from the geophysics, existing hydrogeological and digital elevation data, is presented that provides a framework for groundwater resource determination when/if mineral deposits were to be mined in the region.Keywords: Groundwater, airborne EM, magnetics, hydrogeology.