Marine geology and geophysics of the western South Orkney Plateau, Antarctica: Implications for Quaternary glacial history, tectonics, and paleoceanography
Herron, Margaret Jane
Anderson, John B.
Master of Arts
Piston cores and single-channel seismic profiles were collected from the western South Orkney Plateau to investigate glacial history, survey the seismic stratigraphy, and test the feasibility of paleoceanographic interpretation as a site survey for O.D.P Leg 113 drilling operations. Data reveal evidence for past grounded ice to 240 meters depth, and expanded floating ice cover over the entire plateau. Paleoceanographic interpretation is difficult because nearly 75% of slope cores are affected by sediment gravity flow. All dip-oriented seismic lines show large-scale slumping. Surface sample textural data indicate that wind-driven currents are redistributing sediments in a predictable pattern to about 450 meters depth. Total grain size analyses are necessary to differentiate ice-rafted-debris from other sands. Seismic data support previous interpretations of a passive margin setting, and show up to three seismic sequences within sediment fill on the margin and plateau.
Geology; Physical oceanography; Paleontology