Seismic stratigraphy of the eastern continental shelf of the Wedell Sea, Antarctica
Roqueplo, Christine M.
Clark, Howard C.
Master of Arts
Interpretation of a 1 miles of seismic data, covering the eastern part of the Weddell Sea continental shelf, in Antarctica, reveals a passive margin environment adjacent to the East Antarctic craton. Two major seismic stratigraphic sequences bounded by regional unconformities onlap a highly eroded and possibly faulted acoustic basement. The basement terranes which exhibit high magnetic susceptibilities were tentatively correlated with Mesozoic igneous rocks identified in the Transantarctic Mountains. The older sequence is formed of nearshore deposits which do not contradict the presence of ice on the mainland. The younger sequence, however, exhibits the seismic response expected from glacially derived sediments. The angular unconformity separating both units was probably related to a major (late Oligocene?) drop of sea level, while the erosional event which followed the deposition of the glacial series corresponds to a peak in glacial activity (Pliocene?). Structural framework of the area can only be approached through broad scale studies involving the complex relationships between the East and West Antarctic subcontinents.