Magnetotelluric imaging of a Palaeozoic Andean margin subduction zone in western Victoria

Abstract

A 450 km long transect of broadband (200 Hz – 2000 s) magnetotelluric (MT) sites spaced between 1 and 5 km apart, has been collected across the Palaeozoic Delamerian-Lachlan Orogens in western Victoria. The bandwidth of responses yields resistivity constraints between a few tens of metres in near-surface cover to sub-Moho depths. The passive nature of the source-field means that the MT responses have been collectively assembled in several tranches over ten years, with the last section across the transition between the Orogens collected in June 2014. The MT coverage now completely coincides with a deep crustal reflection seismic transect to generate complementary insight of the crustal structure. We report on preliminary modelling and interpretation.