HR: 0800h
AN: PP51C-0612    [Abstracts]
TI: Long Term Paleoceanographic Variability Across the Paleocene-Eocene Boundary: Correlating Orbital Scale Trends in the North Pacific and South Atlantic
AU: * McCarren, H K
EM: hmccarren@es.ucsc.edu
AF: University of California Santa Cruz, Department of Earth Sciences 1156 High Street, Santa Cruz, CA 95064 United States
AU: Zachos, J C
EM: jzachos@es.ucsc.edu
AF: University of California Santa Cruz, Department of Earth Sciences 1156 High Street, Santa Cruz, CA 95064 United States
AU: Roehl, U
EM: uroehl@marum.de
AF: University of Bremen, DFG Research Center for Ocean Margins (RCOM) Klagenfurter Str. , Bremen, D-28359 Germany
AU: Westerhold, T
EM: tho@uni-bremen.de
AF: University of Bremen, DFG Research Center for Ocean Margins (RCOM) Klagenfurter Str. , Bremen, D-28359 Germany
AB: In order to fully understand the origin and impacts of the Paleocene-Eocene Thermal Maximum (PETM or ETM-1) and subsequent hyperthermal events in the early Eocene (ETM-2, ETM-3), it is essential to constrain the tempo and magnitude of background variability of climate and other key paleoceanographic parameters. However; factors such as deep water temperature, ocean chemistry, and the timing of processes on orbital scales during the early Paleogene remain uncharacterized. This is largely due to the historical unavailability of stratigraphically continuous Paleogene pelagic sections, in addition to the practical limitations of generating high-resolution geochemical and isotope records spanning tens of millions of years. Closely spaced benthic δ ¹⁸O and δ ¹³C measurements, along with weight percent coarse fraction (%CF) and geochemical core logging records spanning the upper Paleocene to lower middle-Eocene from ODP Site 1209 on Shatsky Rise, north Pacific, are compared with bulk δ ¹⁸O and δ ¹³C, %CF, and physical properties data from Site 1262 on Walvis Ridge, south Atlantic. Orbital scale variability is reflected in these records over the early Paleogene. All 3 of the early Eocene hyperthermal events, ETM-1, 2, & 3 (a.k.a, PETM, ELMO, & X) at 55, 53, and 52 Ma respectively, appear to be present along with prominent oscillations in the primary orbital bands. In particular, the carbon isotope record exhibits pronounced power in the 400 k.y. band that can be correlated between the Atlantic and Pacific Sites, and used to identify potential stratigraphic gaps. In addition, there appears to be a long-term transition in the character of carbonate fluxes to the deep-sea, inferred from a rise in the %CF, initiated at the P-E boundary. This might reflect increased preservation of CaCO₃, a potential reduction in coccolith abundances, or a global scale shift in inorganic/organic carbon fluxes.
DE: 4901 Abrupt/rapid climate change (1605)
DE: 4910 Astronomical forcing
DE: 4948 Paleocene/Eocene thermal maximum
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005