West-directed flow of the West Antarctic Ice Sheet across Eastern Basin, Ross Sea during the Quaternary

Detailed seismic–stratigraphic correlations and contour mapping (time-structure and time-thickness) of near-surface units in Eastern Basin, Ross Sea, outer continental shelf suggest that strata outcropping at Ross Bank were deposited as a terminal moraine in association with west-directed advance of the West Antarctic Ice Sheet grounding zone from Marie Byrd Land. During the grounding event, there was a major shift from west-directed ice sheet flow to north-directed ice stream flow. Seismic correlation to age control at DSDP Leg 28 sites 271 and 272 suggests a pre-Last Glacial Maximum Quaternary age for this major grounding event.