HR: 0800h
AN: PP51B-1341    [Abstracts]
TI: Marine Barite and Carbonate Accumulation Rates From Sediment Cores Spanning the Eocene-Oligocene Boundary
AU: * Calhoun, M
EM: mcalhoun@stanford.edu
AF: Department of Geological and Environmental Science, Stanford University, Stanford, CA 94309 United States
AU: Averyt, K
EM: kaveryt@pangea.stanford.edu
AF: Department of Geological and Environmental Science, Stanford University, Stanford, CA 94309 United States
AU: Paytan, A
EM: apaytan@pangea.stanford.edu
AF: Department of Geological and Environmental Science, Stanford University, Stanford, CA 94309 United States
AB: The Eocene-Oligocene (E-O) boundary marked a period of significant worldwide oceanographic and climatic changes. The opening of the Drake Passage around that time, and the resulting formation of a circum-Antarctic sea, allowed for thermal isolation and glaciation on the Antarctic continent. Coupled with this were several global decreases in temperature and a drop in atmospheric CO2. Since export productivity is considered one of the major driving factors of the global carbon cycle, understanding the changes in ocean productivity is important to understanding the mechanism for the climate changes across the E-O boundary. Marine barite is associated with export production to the deep ocean, and barite accumulation rates can be used as a proxy of productivity. Carbonate accumulation rates can be used to assess the productivity of calcite secreting organisms as modified by calcite dissolution. Here we present barite and carbonate accumulation rates for several cores from the Shatsky Rise in the Pacific Ocean that span the E-O boundary. The goal of this data is to assess changes in ocean productivity, seawater chemistry, and changes in the CCD during this time.
DE: 4805 Biogeochemical cycles (1615)
DE: 4203 Analytical modeling
DE: 4267 Paleoceanography
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting