HR: 0800h
AN: PP51D-1355    [Abstracts]
TI: Eocene-Oligocene Southern Ocean Paleo-bathymetry maps generated with geophysical, sedimentological and microfossil data.
AU: * Brown, B J
EM: belinda@geosci.usyd.edu.au
AF: University of Sydney Institute of Marine Science, Edgeworth David Building F05, School of Geosciences, The University of Sydney, Sydney, NSW 2006 Australia
AU: Warnaar, J
EM: J.Warnaar@bio.uu.nl
AF: Department of Biogeology and Palaeo-Ecology, Laboratory of Palaeobotany and Palynology, Utrecht University Aardwetenschappen, Budapestlaan 4,, Utrecht, CD 3584 Netherlands
AU: Gaina, C
EM: carmen@geosci.usyd.edu.au
AF: University of Sydney Institute of Marine Science, Edgeworth David Building F05, School of Geosciences, The University of Sydney, Sydney, NSW 2006 Australia
AU: Muller, D
EM: dietmar@geosci.usyd.edu.au
AF: University of Sydney Institute of Marine Science, Edgeworth David Building F05, School of Geosciences, The University of Sydney, Sydney, NSW 2006 Australia
AU: Brinkhuis, H
EM: H.Brinkhuis@bio.uu.nl
AF: Department of Biogeology and Palaeo-Ecology, Laboratory of Palaeobotany and Palynology, Utrecht University Aardwetenschappen, Budapestlaan 4,, Utrecht, CD 3584 Netherlands
AB: The Eocene-Oligocene transition is characterized by the cooling of the Southern Ocean region and growth of the Antarctic ice-sheet. Through this transition, changes in spatial distribution and topography of land masses and ocean basins have played a role. Our objective is to produce a set of enhanced paleo-bathymetry maps based on both plate reconstruction models for the Southern Ocean and sedimentological and microfossil data. We used paleo-age grids to create a series of paleoceanic basement-depth grids, based on a thermal boundary layer depth-age model. We further constrained these paleo-bathymetry grids, especially for continental margins, with sedimentological and microfossil data (diatoms, foraminifera, nannofossils, organic walled dinoflagellates, pollen & spores and radiolarians); derived from new and published data from land based sections and DSDP/ODP (and other) cores. In particular, we aim to map the opening of oceanic gateways (Tasmanian Gateway and Drake Passage) and changing ocean topography through Eocene-Oligocene times. It is known that the evolution of circum Antarctic current systems were strongly dependent on bottom topography, particularly the deepening of oceanic gateways and the mid-ocean ridge system. It is hoped that this work will offer a more realistic/resolved starting input for ocean basin configuration (paleo-geographic model) and topography (paleo-bathymetry model). It would be a valuable tool to assess boundary conditions for oceanographic circulation models and next generation CCM's; in particular it would help assess deep-water circulation and related climate change further back in geological time.
DE: 9310 Antarctica
DE: 9604 Cenozoic
DE: 4207 Arctic and Antarctic oceanography
DE: 4267 Paleoceanography
DE: 3045 Seafloor morphology and bottom photography
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting