Break-up of Gondwana and Assembly of Antarctica

Abstract

Antarctica, as we know it, is a large landmass that is completely surrounded by the Atlantic, Indian, and Pacific oceans. Seen from space, the ice sheets that cover East and West Antarctica gleam by the sunlight they reflect. Actually, the interior of West Antarctica is a large tectonic rift that lies below sea level. Even the subglacial bedrock surface of the Wilkes Basin of East Antarctica is below sea level. In the bathymetric image in Fig. 15.1, Antarctica is depicted as an elevated continent in hues of brownish red and yellow because the elevation of the East Antarctic ice sheet increases from sea level along the coast to about 4,000 m at Dome A in the interior. Even the elevation of the West Antarctic ice sheet exceeds 2,000 m in the Whitmore Mountains and in parts of Marie Byrd Land (e.g., Executive Committee and Flood ranges). Although the geologic history of East Antarctica extends more than three billion years into the Archean Eon, the present appearance of Antarctica dates from the Cenozoic Era that started at the end of the Cretaceous Period 65 million years ago.