Continental Crust Fragmentation, Small Basin Development And Deep Water Circulation In The Southern Scotia Sea (Southern Atlantic)

The development of the Scotia Plate between the<br>South American and Antarctic plates since the<br>Oligocene has produced the fragmentation of the<br>former continental crustal strip that connected South<br>America and the Antarctic Peninsula. This<br>fragmentation developed numerous small oceanic<br>basins bounded by blocks of stretched continental<br>crust, which resulted in the present-day conspicuous<br>structure of the Scotia Arc and the neighbouring<br>areas. Seismic, gravity, magnetic and multibeam<br>profiles were recorded in Protector Basin during the<br>SCAN 2001 cruise on board of the B/O Hesperides.<br>This basin of Middle-Late Miocene age constitutes a<br>good example of small oceanic basin bounded by<br>thinned continental crust. A profile of the southern<br>basin shows the spreading ridge and the symmetrical<br>oceanic magnetic anomalies. The basin, however,<br>northward is very asymmetrical and ends by the<br>closure of both continental margins. The Scotia Plate<br>is in fact a complex mixture of oceanic and<br>continental crust fragments that determines the deep<br>water circulation in the region.