The development of morphologies follow initially the tectonic displacement structures of thebasement and sediments. Such tectonic lineaments are often exploited by surface erosional processes and play an important role in reconstructing past ice sheet dynamics. Observations of bathymetric features of the continental shelf of the Amundsen Sea Embayment and identification of tectonic lineaments from geophysical mapping indicate that erosional processes of paleo-ice stream flows across the continental shelf followed such lineaments inherited from the tectonic history since the Cretaceous breakup between New Zealand and West Antarctica. East-west oriented basement trends correlate with coastline trends and overlay tectonic lineaments caused by former rift activities. Directional trends in northwest-southeast orientation are observed for the glacial troughs of the western embayment outer shelf, the western Pine Island Bay coastal zones, and the inner Pine Island glacial trough and are superposed on a distributed southern plate boundary zone of the former Bellingshausen Plate. The north-south trend of the main Pine Island glacial trough and the NNE-trend of the Abbot Ice Shelf trough follow the predicted lineation trend of an eastern branch of the West Antarctic Rift System extending from the Thwaites drainage basin northward into Pine Island Bay. An understanding of this context helps better constrain the geometries and sea-bed substrate conditions for regional paleo-ice sheet models.
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 3: Lessons from the Past > WP 3.2: Tectonic, Climate and Biosphere Development from Greenhouse to Icehouse