Seismic analysis and models from a rifted submarine plateau of continental origin: Great South Basin and Bounty Trough (New Zealand)

• Main Authors: Grobys, Jan, Gohl, Karsten, Uenzelmann-Neben, Gabriele, Davy, B., Barker, D., Deen, T.
• Format: Conference Object
• Language: unknown
• Published: 2006
• Subjects: Antarc*; Antarctica; Marie Byrd Land
• Online Access: https://epic.awi.de/id/eprint/15531/; https://hdl.handle.net/10013/epic.25659

The Campbell Plateau and Chatham Rise are large submarine plateaux of continental origin forming parts of the submarine New Zealand continent. Prior to the break-up of this part of Gondwana, New Zealand was situated at the proto-Pacific plate boundary of Gondwana, connected to Marie Byrd Land. It is expected that the development of the continental fragments forming Campbell Plateau and Chatham Rise played a key role in the development of Gondwanas plate boundary from a convergent margin to continental rifting. Our new crustal models of Bounty Trough and Great South Basin infer thinned crust beneath both basins. The crust beneath the Bounty Trough is extremely thinned up to nascent seafloor spreading. Seismic information implies that several extensional phases and styles (pure shear and simple shear) have occurred. Beneath the Great South Basin, the crust is less thinned and underplating can be observed in some areas. Our models as well as geologic information suggest, that an initial extension of the Campbell Plateau predates the Great South Basin opening in Cretaceous time. This information related to the magnitude and style of rifting along Bounty Trough and Great South Basin, influence models of the break-up process between New Zealand and Antarctica that will be presented here.