HR: 0800h
AN: C51B-0382    [Abstracts]
TI: Do laminated sediment-gravity-flow deposits on the Antarctic Peninsula continental shelf record ice shelf grounding events?
AU: * Adams, V
EM: vc_adams@yahoo.com
AF: Louisiana State University, Department of Geology and Geophysics, Baton Rouge, La 70808,
AU: Bart, P
EM: pbart@lsu.edu
AF: Louisiana State University, Department of Geology and Geophysics, Baton Rouge, La 70808,
AB: Drifts on the continental rise of the Antarctic Peninsula may contain a high-resolution record of ice-sheet expansion on the adjacent continental shelf (Baker and Carmerlenghi, 1999). During major ice-sheet grounding events, sediment is delivered to the outer continental shelf and upper slope. Associated slope instabilities trigger additional mass transport to the continental rise and abyssal plain. Therefore, major glacial periods should be recorded on the continental rise by laminated sediment-gravity-flow deposits within the drifts. When grounded ice retreats during interglacials, sedimentation rates would decline and the tops of laminated sections should be bioturbated. In this ongoing study, we compile the laminated-bioturbated couplets from ODP Leg 178 Sites 1095, 1096, and 1101. We are in the process of evaluating whether the timing and frequency of the sediment cycles on the drift are possibly related to orbital forcing as opposed to an uneven distribution of sediment input from the outer continental shelf and/or bioturbation on the drift.
DE: 0700 CRYOSPHERE (4540)
DE: 0726 Ice sheets
SC: Cryosphere [C]
MN: 2007 Fall Meeting