 During the Eocene to Miocene clockwise relative rotation of West Antarctica with respect to East Antarctica resulted in extension in the western Ross Embayment but contraction, in Marie Byrd Land of West Antarctica.Subsidence to form the present topography of the embayment continued through the Cenozoic as the extended crust and mantle under the Ross Embayment cooled.Faulting within the Terror Rift, located in the Victoria Land Basin, continued after 11 Ma, and probably into or through Quaternary time.