| Summary: | The South Scotia Ridge (SSR) is a submerged structural high located at the eastern continuation of the Antarctic Peninsula and representing the Scotia-Antarctica transform plate boundary. A three-dimensional geological model of a sector of the SSR was built using reflection seismic and sea-floor bathymetry. The model covers the boundary between the oceanic crust of the Scotia Sea and the continental crust of the South Scotia Ridge, where the orientation of the SSR structure changes from SW-NE to W-E. Most of the active faults are located within the continental crust, however, deformation locally involves the oceanic crust and appears connected to the orientation and geometry of the fault system which defines the continent-ocean boundary. The 3D geological model helps visualize a western and central province where the active boundary involves continental blocks, the continental slope, the oceanic basement and sediments, and an eastern province where the sedimentary cover is not deformed and the oceanic basement dips underneath the continent. Moving from west to east, the NW-dipping main transtensional fault system becomes almost vertical in the central sector with an almost pure sinistral strike-slip movement. To the east, a south-dipping plane is progressively less inclined and changes orientation: here evidence of shortening is visible.
|
|---|