Thick- and thin-skinned style deformation regimes, eastern Melbourne Zone ? implications for tectonic evolution and mineral exploration in the Woods Point?Walhalla region

Abstract

GeoScience Victoria (GSV) has recently completed detailed mapping and geophysical modelling of a large portion of the eastern Melbourne Zone in Central Victoria. This region encompasses the Walhalla and Woods Point goldfields, as well as subsidiary goldfields such as Enochs Point and Tallangallook. The work has recognised two north-trending structural subzones. The western thick-skinned subzone abuts the eastern thin-skinned subzone along a high-angle fault system. This fault system links into a basal detachment system that may underlie both subzones and separates the Melbourne Zone from its structural basement: Cambrian igneous rocks that are part of the Selwyn Block. This new structural understanding helps explain the location of the main goldfields, which lie adjacent to the transition between subzones.