A set of multi-channel seismic profiles (~15000 km) acquired by Russia, Norway and Australia has been used
to investigate the depositional evolution of the Cosmonaut Sea margin of East Antarctica. We recognize a regional
sediment wedge below the upper part of the continental rise. The wedge, 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 and from 80 to about 250 km seaward or to the north. Lateral variations in the growth pattern of the
wedge indicate several overlapping depocentres, which at their distal northern end are flanked by elongated mounded
drifts and contourite sheets. The internal stratification of the mounded drift deposits suggests that westward flowing
bottom currents reworked the marginal 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 bottom current reworked fan systems.
