HR: 0800h
AN: PP41C-0690    [Abstracts]
TI: Synchronic Response of Arctic Ice-Sheets to Global Climate Deterioration During the Plio- Pleistocene
AU: * Knies, J
EM: jochen.knies@ngu.no
AF: Geological Survey of Norway, Leiv Eirikssons vei 39, Trondheim, 7491, Norway
AU: Matthiessen, J
EM: jens.matthiessen@awi.de
AF: Alfred Wegener Institute for Polar and Marine Research, Columbusstrasse, Bremerhaven, 27568, Germany
AU: Vogt, C
EM: cvogt@uni-bremen.de
AF: University of Bremen, Klagenfurter Strasse, Bremen, 28359, Germany
AB: Here, we report the revised chronostratigraphic and new sedimentological data of various ODP boreholes (Legs 151, 162) in the Atlantic-Arctic gateway region to present a coherent glaciation model for the Barents Sea ice sheet over the past 3.5 Ma. Pulses of IRD during the Northern Hemisphere Glaciation (NHG) at ~2.7 Ma indicate consistency of glacial dynamics of circum-Arctic ice sheets to global climate deterioration. However, large-scale expansion of the Barents Sea ice sheet towards the shelf edge are not evident before ~1.5 Ma. This is inferred not only from IRD pulses but also from a step-wise decrease of Siberian river supplied smectite-rich sediments likely caused by ice-sheet blockade and glacigenic wedge growth along the northern and western Barents Sea margin. Large-scale glaciation in the Barents Sea occurs since ~1 Ma (Mid-Pleistocene Transition) and repeatedly advanced to the shelf edge at least 7 times thereafter. The timing is inferred from ice grounding on the Yermak Plateau at ~0.9 Ma attributed to a pronounced ice sheet advance or deep-draft icebergs and higher frequencies of gravity-driven mass movements along the western Barents Sea margin associated with glacial growth.
DE: 1521 Paleointensity
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting