Scale reduction using magnetotellurics – a mineral exploration example from the Olympic Domain, South Australia

Abstract

We present results of 334 ultra-wide band MT stations across an area of 100 km x 100 km in the prospective eastern Gawler Craton. The survey area is situated ~100 km south of the supergiant Olympic Dam IOCG deposit, across an area of several IOCG deposits and prospects, including Carrapateena, Oak Dam, and Khamsin. Station spacing varies between 5 km and reduces to 1.5 km around areas of known IOCG prospects. The 3D resistivity models show a north-south oriented conductor in the upper crust. Known IOCG prospects are situated along its margins. These results expand the previously only 2D defined signatures of IOCG deposits, such as Olympic Dam to the full 3D domain. Together with the wider-spaced AusLAMP deployment and a 1.5km to 3 km spaced AEM survey, the survey is unique for imaging the whole-of-lithosphere footprint of IOCG deposits under cover.