Karsten Gohl, Dept. of Geosciences, Alfred Wegener Institute for Polar and Marine Research, Columbusstrasse, Bremerhaven, 27568, Germany
Antarctica was a centerpiece of the Gondwana supercontinent. About 85 percent of Antarctica’s 10000 km long continental margins are of a rifted divergent type, and about 1200 km have been converted from a subduction-type to a passive margin after ridge-trench collision along the Pacific side of the Antarctic Peninsula. In recent years, the amount of geophysical data along the continental margin of Antarctica has increased substantially, which allows us to differentiate the crustal characteristics of its continent-ocean boundaries and transitional zones (COB/COT). The data and geodynamic modeling indicate that the cause, style and process of breakup and separation were quite different along the Antarctic margin. A circum-Antarctic map will show the crustal styles of the margin and the location and geophysical characteristics of the COT. Definitions of the COT and understanding its process of formation have consequences for plate-kinematic reconstructions and geodynamic syntheses.
