HR: 08:15h
AN: PP51F-02    [Abstracts]
TI: Drake Passage and Cenozoic climate: an open and shut case?
AU: * Livermore, R
EM: ral@bas.ac.uk
AF: British Antarctic Survey, High Cross Madingley Road, Cambridge, CB3 0ET United Kingdom
AU: Hillenbrand, C
EM: hilc@bas.ac.uk
AF: British Antarctic Survey, High Cross Madingley Road, Cambridge, CB3 0ET United Kingdom
AU: Meredith, M
EM: mmm@bas.ac.uk
AF: British Antarctic Survey, High Cross Madingley Road, Cambridge, CB3 0ET United Kingdom
AU: Eagles, G
EM: geagles@awi-bremerhaven.de
AF: Alfred Wegener Institute for Polar and Marine Research, Columbusstrasse, D-27568, Bremerhaven, DEU D-27568
AB: Drake Passage opening has often been viewed as a single, discrete, event, possibly associated with abrupt changes in global circulation and climate at or near the Eocene-Oligocene boundary. A new plate tectonic model, based on recent re-interpretations of the opening history of basins in the Scotia Sea, suggests that an effective ocean gateway may have developed much earlier, during the Middle Eocene. This is consistent with a growing body of evidence from sediment core proxy data for Eocene changes in Southern Ocean circulation and biological productivity. The period between earliest opening at ~50 Ma and the latest Eocene was characterised by the evolution of various current pathways across the subsiding continental shelves and intervening deep basins. This shallow opening may have caused important changes in Southern Ocean circulation, contributing to Eocene cooling and the growth of Antarctic ice-sheets.
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 4901 Abrupt/rapid climate change (1605)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005