An electrical resistivity model of the southeast Australian lithosphere

Abstract

Data from 68 broadband magnetotelluric stations were inverted to obtain a 2D electrical resistivity model beneath the Delamerian Orogen in southeast Australia along a 150 km east-west transect. Station spacing of 5 km in the west and ~2 km in the east resolved structure with changes in resistivity from 10-10,000 Ωm occurring laterally over several kilometres. To the west, the crust is generally resistive, with a more complex structure to the east involving narrow paths of low resistivity (10-300 Ωm). These conductive regions extend from Moho depths up to the surface and align with fault structures. The narrow conductive pathways possibly track mineral alterations from reactions with mantle fluids moving upwards late in the Delamerian Orogeny.