Wednesday, 29 August 2007 - 11:50 AM
3.A.A-6
The Cosmonaut Sea Wedge
Kenneth Solli, Department of Earth Science, University of Bergen, Allegaten 41, N-5007, Bergen, Norway
In the Cosmonaut Sea margin of East Antarctica (35º–55ºE), we recognize a regional sediment lens below the upper part of the continental rise. The lens, herein termed the Cosmonaut Sea Wedge, is positioned stratigraphically underneath the inferred glaciomarine section and extends for at least 1200 km along the continental margin with a width that ranges from about 80 to 250 km. Lateral variations in the growth pattern of the wedge indicate several overlapping depocentres, which are flanked by elongated mounded drifts and contourite sheets at their distal northern ends. The internal stratification of the mounded drift deposits suggests that westward-flowing bottom currents reworked the margin deposits. The action of these currents, together with sea-level changes, is considered to have controlled the growth of the wedge. We interpret the Cosmonaut Sea Wedge as a composite feature comprising several fan systems reworked by bottom currents.