HR: 0830h
AN: PP21C-1181    [PDF]
TI: The Environmental Impact of the Paleocene-Eocene Thermal Maximum on the Coastal Ocean, New Jersey: Inferences from Stable Isotope, Trace Metal, and Organic/Inorganic Carbon Records
AU: * Quattlebaum, T G
EM: thomasq@es.ucsc.edu
AF: University of California, Santa Cruz, Earth Sciences Department, Santa Cruz, CA 95064 United States
AU: Bohaty, S
EM: sbohaty@es.ucsc.edu
AF: University of California, Santa Cruz, Earth Sciences Department, Santa Cruz, CA 95064 United States
AU: Zachos, J C
EM: jzachos@es.ucsc.edu
AF: University of California, Santa Cruz, Earth Sciences Department, Santa Cruz, CA 95064 United States
AU: Delaney, M
EM: delaney@ucsc.edu
AF: University of California, Santa Cruz, Ocean Sciences Department, Santa Cruz, CA 95064 United States
AU: Anderson, L
EM: linda@ucsc.edu
AF: University of California, Santa Cruz, Ocean Sciences Department, Santa Cruz, CA 95064 United States
AU: Bybell, L
EM: lbybell@usgs.gov
AF: U.S. Geological Survey, 926 National Center, Reston, VA 20192 United States
AB: Approximately 55 million years ago, the Earth experienced an abrupt transient global warming, the Paleocene-Eocene Thermal Maximum (PETM). Two shallow marine sections across the PETM were cored near Clayton, New Jersey. Nannofossil biostratigraphy along with carbon isotope stratigraphy were used to identify the boundary and to constrain the thickness of the PETM. The excursion layer appears to be expanded (~15 m), though the early Eocene is truncated by erosion. The Wilson Lake and Clayton cores, along with data from other northeastern U.S. localities within the same embayment, reveal significant biologic and mineralogical anomalies across the CIE. For example, the Wilson Lake core contains a pronounced increase in relative abundance of dinoflagellate cysts (dinocysts) assigned to the genus Apectodinium around the event, increasing from $<$1% below the CIE transition to 52% within, as well as a pronounced spike in kaolinite content. A suite of geochemical analyses including stable isotopes was generated for the Wilson Lake core at high resolution to constrain temperature/salinity, organic/inorganic C fluxes and redox conditions. The isotope records show dramatic negative excursions in $\delta$$^{13}$C and $\delta$$^{18}$O, with a 6$\permil$ negative carbon shift in bulk sediments. Carbonate content decreases to $<$1% at the $\delta$$^{13}$C bulk minimum and then increases to a maximum of 15% 3 m above. The benthic and planktonic foraminifer isotope records show excursions but of much smaller magnitudes than recorded in bulk carbonate implying a meteoric diagenetic overprint on the bulk isotope signal. Uranium, manganese, and barium data indicate minor shifts in the redox conditions of bottom waters during the excursion. Substantial manganese enrichment over much of the interval suggests that oxidative conditions dominate during the event consistent with the low organic carbon content ($<$1%). At the top of the section, a spike in uranium indicates a shift to suboxia in the late stages of system recovery. The lack of barium enrichment during the event suggests that there was little change in local paleoproductivity.
DE: 3030 Micropaleontology
DE: 4203 Analytical modeling
DE: 4267 Paleoceanography
DE: 4870 Stable isotopes
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting