Neoproterozoic and Cambrian continental rifting, continent-arc collision and post-collisional magmatism

Abstract

Major advances have been made over the last decade in our understanding of the distribution, compositions, age and significance of Late Neoproterozoic and Cambrian rocks in Victoria.These advances have been driven mainly by the new generation of geological mapping carried out by the Geological Survey of Victoria, using detailed aeromagnetic, gravity and radiometric datasets covering much of the state. In addition, detailed work by universities over certain areas, particularly the Glenelg region in the far west and locally around Stawell, have made significant contributions to the knowledge of the Cambrian geology. In western Victoria, Cambrian rocks comprise all the known sedimentary and volcanic bedrock as well as numerous granites. Although there is some possibility of Proterozoic rocks occurring here, no dated rocks have returned ages older than Cambrian. The rock units and geological histories of the Glenelg, Grampians, Stavely and Stawell zones, which were poorly known until recently, are now much better understood. In central and eastern Victoria, the Cambrian rocks generally lie at deeper structural levels and are only exposed in the hanging walls of major faults. Important new information is available for the Glenelg River Complex in westernmost Victoria, the exposed and drilled volcanic belts in western Victoria, and the Cambrian greenstones around Pitfield and on Phillip Island.