HR: 17:15h
AN: C44A-06    [Abstracts]
TI: Overview of Late Pleistocene Diatom Biostratigraphic Records From Eastern, Central and Northern Basins in the Ross Sea Compared to Seismic Architecture of Sediment Strata
AU: * Chow, J
EM: jchow1@lsu.edu
AF: Louisiana State University, Department of Geology and Geophysics E235 Howe-Russell, Baton Rouge, LA 70803, United States
AU: Sjunneskog, C
EM: charlottems60@yahoo.com
AF: Louisiana State University, Department of Geology and Geophysics E235 Howe-Russell, Baton Rouge, LA 70803, United States
AB: Models of ice grounding during LGM indicate that grounding occurred in the vicinity of the continental shelf break in the Eastern and Central Ross Sea, whereas in the Western Ross Sea the grounding line was in the vicinity of Coulman Island. Numerous piston cores have been collected from the Eastern, Central, and Western Ross Sea continental shelf, with the aim of obtaining a chronological and stratigraphical constraint on the LGM. However, only a few cores have been recovered from the Northern Basin. In Eastern Basin, grounding line features (till deltas) are built of six distinct seismic units deposited by the West Antarctic Ice Sheet. The Central Basin and Pennell Bank are characterized by troughs and banks with ice recessional ridges. During the 2003 austral summer, cruise NBP03-01A collected 10 piston and jumbo piston cores from the Northern Basin in a depth transect across Drygalski Trough – Mawson Bank, at the upper continental slope. The lithologies of the cores include diatom mud, bioclastic sediment, silt, sand, clay, and diamicton. This is in contrast to piston cores from Central and Eastern Basins, where sediment is dominated by diamicton associated with the advance of grounded ice. Here we compare diatom assemblages from the three different basins with these questions in mind: Are the different seismic units of Eastern Basin of the same age and origin? Is there a difference in the composition of Central and Eastern Basin diamictons? How does the late Pleistocene sediment from Northern Basin deposited by the East Antarctic Ice Sheet relate to the Eastern and Central Ross Sea?
DE: 0799 General or miscellaneous
SC: Cryosphere [C]
MN: 2007 Fall Meeting