The Lithosphere

Paleozoic tectonics of the Gondwana margin

Principle Investigator: Prof. J. D. Bradshaw
Organisation: University of Canterbury

During the Cambro-Ordovician period, Victoria Land and New Zealand were parts of the active margin of the Gondwana continent. A picture is emerging of an active continental margin of Andean type and the accretion of one or more intra-oceanic arc terranes between 500 and 485 Ma. This points to the presence of two or more contemporaneous subduction zones. In northern Victoria Land, the Bowers terrane was accreted in the Late Cambrian. In southern Victoria Land changes in composition of basement granites in the Dry Valleys have been attributed to the arrival of a similar exotic terrane. The latter hypothesis can be tested by examining clasts in the Sperm Bluff Conglomerate (Taylor Group, Beacon Supergroup) in the Dry Valleys area. The clasts are of lithologies not found in southern Victoria Land and a combined petrological, geochemical and geochronological study of sedimentary and igneous clasts would establish their provenance. The results would contribute to the understanding of the history and dynamics of the Gondwana margin and the Ross Orogen, the provenance and paleogeography of the Taylor Group basin, and the basement of the Victoria Land basin.

Recent Publications:
Savage, J. E. Provenance analysis of the Sperm Bluff Formation, southern Victoria Land, Antarctica. M.Sc. University of Canterbury, 2005.