HR: 0800h
AN: PP41C-0684    [Abstracts]
TI: Environmental Magnetism From the Gardar Drift Since MIS5e
AU: * Evans, H F
EM: geohelen@ufl.edu
AF: Department of Geological Sciences, 241 Williamson Hall Po Box 112120, Gainesville, FL 32611, United States
AU: Hodell, D A
AF: Department of Geological Sciences, 241 Williamson Hall Po Box 112120, Gainesville, FL 32611, United States
AU: Channell, J E
AF: Department of Geological Sciences, 241 Williamson Hall Po Box 112120, Gainesville, FL 32611, United States
AB: A series of cores along NE-SW transect across the Gardar Drift were collected during a cruise of the RV Knorr in 2002. U-channel samples taken from three cores (JPC2, JPC5 and JPC13) show significant changes in magnetic properties (magnetic susceptibility, magnetic grain size) along the drift transect. Changes in magnetic (magnetite) grain size, as indicated by karm/k, may provide a proxy for strength of bottom currents moving over the drift. On the northern section of the drift (Core JPC2), changes in magnetic grain size can be seen to track glacial/interglacial cycles, with coarser grain sizes in MIS1 and MIS5 and finer grain sizes in MIS2 and MIS4, with a coarsening trend with age in MIS3. On the southern end of the drift (Core JPC13), magnetic grain size fluctuations in MIS3 accompany melt-water events identified by low planktic oxygen isotope values. This may be interpreted in terms of bottom-current strength variations in response to surface melt-water events. Volume magnetic susceptibility decreases southwest along the drift and cannot be correlated amongst the cores. The benthic oxygen isotope record from Core JPC13 can be clearly correlated to the benthic isotope record from Core MD95-2042 from the Portuguese Margin that has been correlated to the GISP ice core via its planktic oxygen isotope record (Shackleton et al., 2004, SFCP04). This allows Core JPC13 to be placed on the SFCP04 GISP chronology.
DE: 1512 Environmental magnetism
DE: 1521 Paleointensity
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting