HR: 0830h
AN: PP51C-0942    [PDF]
TI: Neodymium Isotopic Composition of Terrigeneous Sediment as a Monitor of Bottom- and Surface Currents: an Example From the Fram Strait
AU: * Schmitt, W M
EM: schmitt@min.uni-muenchen.de
AF: Department of Earth- and Environmental Sciences, LMU Munich, Theresienstr. 41/III, Munich, 80333 Germany
AU: Hass, H
AF: Alfred-Wegener-Institute for Polar- and Marine Research, Wadden Sea Station Sylt, Hafenstr. 43, List, 25992 Germany
AU: Hegner, E
AF: Department of Earth- and Environmental Sciences, LMU Munich, Theresienstr. 41/III, Munich, 80333 Germany
AU: Fuetterer, D K
AF: Alfred-Wegener-Institute for Polar- and Marine Research, Columbusstr., Bremerhaven, 27568 Germany
AB: A high resolution sediment core from the northeastern Fram Strait (Arctic Ocean) was investigated to reconstruct fluctuations of bottom- and surface currents related to climate change during the Late Quaternary. Neodymium isotopic compositions were determined for four different grain size fractions ($<$2 $\mu$m, 2-10 $\mu$m, 10-63 $\mu$m, $>$63 $\mu$m) of 17 samples covering the last 130 ka. These grain size fractions are assumed to monitor different transport mechanisms such as current transport and ice rafting. The neodymium isotopic composition of terrigeneous sediment is not affected by grain size variations or uptake of dissolved neodymium from sea water, and therefore reflects the isotopic composition of the source rock. This can be used to trace sediment pathways. The neodymium isotopic data indicate that sediments deposited at the core location are a mixture of material derived mainly from Spitsbergen and the Lena-, Ob-, and Yenisei Rivers (Siberia). Variations of the isotopic compositions with time reveal variable contibutions of the source areas as a result of changed oceanographic conditions. Only relatively small isotopic variations are found during MIS 3, 4, and 5, whereas major changes of the oceanographic conditions are indicated during the LGM and the early Holocene.
DE: 1040 Isotopic composition/chemistry
DE: 1600 GLOBAL CHANGE (New category)
DE: 3022 Marine sediments--processes and transport
DE: 9315 Arctic region
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting