Tuesday, 28 August 2007 - 2:10 PM
2.P1.A-3
Cenozoic environmental changes along the East Antarctic continental margin inferred from regional seismic stratigraphy
German L. Leitchenkov1, Yulia B. Guseva2, and Victor V. Gandyukhin2. (1) Antarctic geology, Institute for Geology and Mineral Resources of the World Ocean (VNIIOkeangeologia), Angliiskiy ave., 1, St.Petersburg, 190121, Russia, (2) Antarctic geology, Polar Marine Geosurvey Expedition, 24 Pobeda Street, St. Petersburg, Lomonosov, 189510, Russia
We interpret ~40 000 km of multichannel seismic reflection data collected by the Russian Antarctic Expedition along the East Antarctic continental margin from 30º–115ºE and present a revised seismic stratigraphy model for the regional depositional paleoenvironments. Variations in acoustic facies observed across major unconformities are correlated with paleoenvironmental changes deciphered from Antarctic drilling data and deep-sea “proxy” records. As with other studies, our results indicate that the East Antarctic margin was glaciated at different times, with the ice sheet first reaching the western Wilkes Land margin in the Middle Eocene and then advancing onto most parts of the East Antarctic continental shelf in the earliest Oligocene. In the Neogene, bottom currents deposited a variety of drift deposits along the margin.