Abstract:

There we analysised the data were collected using our survey ship-Ocean Ⅳin the Bransfield Strait in 1991. We recognized that the geomorphology、gravity and magnetic anomalies trend NE direction as bandings. The sediments in the Bransfield Strait are subdivided into two sequences:first rifting sequence and second rifting sequence. The basement was faulted into a half graben faulting in northwest side of the Bransfield trough. Considered the crustal structure crossing the South Shetland Islands、Bransfield Strait and Antarctic Peninsula,we proposal a two phase rifting tectonical evolution model and layered shear model for the lithospheric deformation under extensional stress field.