Carpentaria Conductivity Anomaly revisited with preliminary magnetotelluric results from the SE Mt Isa Survey 2014

Abstract

The region to the east of Mt Isa has complex electrical conductivity, with conductive basin sediments overlying the deeper Carpentaria Conductivity Anomaly (CCA). Early magnetotelluric (MT) model results show alignment of the CCA with aeromagnetic, gravity and seismic features, together implying that they define the major structural edge of the Mt Isa Block. Profile MT data acquired during the previous 20 years have helped refine the position and depth of the CCA. New MT and deep seismic reflection data have recently been acquired in 2014 along a NW to SE profile, funded by the Geological Survey of Queensland's Greenfields 2020 Program in conjunction with Geoscience Australia. These new data provide further evidence of the complex nature of the crustal conductivity in this region. Induction vectors indicate that the CCA itself is braided into several zones which may define deep-seated fracture systems.