Thin-sheet electromagnetic modelling of the Australian continental crust

Abstract

An electrical conductance model for the Australian region has been compiled, based on the gross surface geology and typical conductance values for crystalline terranes, sedimentary basins, seawater and ocean crust. The electromagnetic response of this "thin-sheet" model is consistent with the observed coast effect around the edge of the continent. Within the continent, strong conductivity anomalies previously identified by magnetometer array studies are not reproduced unless conductances along their paths are increased substantially. However, such enhancement may not be geologically unrealistic.