HR: 0830h
AN: PP31B-0254    [PDF]
TI: {\it Eucampia antarctica} (Diatom) Stratigraphy Allows Correlation of Millennial-Scale Events in the Southern Ocean
AU: * Anderson, B E
EM: Brenton.Anderson@sunysb.edu
AF: Lamont-Doherty Earth Observatory, P.O. Box 1000, Palisades, NY 10964 United States
AU: * Anderson, B E
EM: Brenton.Anderson@sunysb.edu
AF: State University of New York, North Loop Rd., Stony Brook, NY 11790 United States
AU: Burckle, L H
EM: burckle@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, P.O. Box 1000, Palisades, NY 10964 United States
AU: Anderson, R F
EM: boba@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, P.O. Box 1000, Palisades, NY 10964 United States
AB: Whether or not the Antarctic ice sheet experienced instabilities during the Last Glacial Maximum (LGM), similar to those that characterized periods of abrupt climate change in the North Atlantic, remains unresolved due to the difficulty in establishing reliable high-resolution chronologies for Southern Ocean sediments. We developed a stratigraphy, based on relative abundance of {\it Eucampia Antarctica} to provide a signal that is correlative throughout many areas of the Southern Ocean. Three high-resolution records (two in the Atlantic and one in the Pacific sector) have been developed in which {\it E. Antarctica} stratigraphy and the Vostok deuterium record are well correlated at near-millennial resolution over the past 80 ka. Magnetic susceptibility (MS) was measured in three cores as a proxy for ice-rafted debris (IRD). When the {\it E. Antarctica} stratigraphies in two cores in relatively close proximity (RC13-271 and TN057-14; $52\deg$S, $4.5\deg$E) were aligned, the MS records show nearly identical patterns, indicating that our approach detects correlated IRD events under circumstances where such a correlation would be expected. {\it E. Antarctica} and MS records in RC11-78, nearly 800 km to the west of these two cores, were then used to test our ability to detect correlated IRD events over broader spatial scales. After aligning the stratigraphies of the cores based on {\it E. Antarctica} abundance, we found that the MS peaks in RC11-78 are generally well correlated with those in the other cores with the exception of two thick volcanic ash layers in RC13-271 and TN057-14 that may reflect local deposition. {\it Eucampia Antarctica} stratigraphy offers excellent promise for correlating events in Southern Ocean sediments.
DE: 3022 Marine sediments--processes and transport
DE: 3030 Micropaleontology
DE: 3309 Climatology (1620)
DE: 4207 Arctic and Antarctic oceanography
DE: 4267 Paleoceanography
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting