HR: 0800h
AN: PP41D-0774    [Abstracts]
TI: Geochemical and Paleoceanographic Examination of the Cenozoic Arctic Ocean: Results from IODP ACEX 302.
AU: * Martinez, N C
EM: nahysa@bu.edu
AF: Boston University, Dept. Earth Sciences, Boston, MA 02215, United States
AU: Murray, R W
EM: rickm@bu.edu
AF: Boston University, Dept. Earth Sciences, Boston, MA 02215, United States
AU: Dickens, G R
EM: jerry@rice.edu
AF: Rice University, Dept. Earth Sicences, Houston, TX 77005, United States
AU: Kölling, M
EM: koelling@uni-bremen.de
AF: University of Bremen, Dept. Geosciences, Bremen, 28359, Germany
AB: We have analyzed sediments from Integrated Ocean Drilling Program Arctic Coring Expedition 302 in the central Arctic Ocean, for major, trace, and rare earth elements in order to assess detrital source changes to the Lomonosov Ridge throughout the Cenozoic. The terrigenous component consists of two compositional end- members, one with a shale-like composition and another with a more basaltic affinity. The shale end-member contributes the most over Unit 1 and the older portions of Unit 3, and may represent sediment supplied from the eastern Laptev Sea (drained by the Lena and Yana rivers). Therefore, even though transport mechanisms must have significantly changed from ice-free to ice-driven, these two units could have been under the influence of a single major terrigenous source. Input from the more basaltic end-member appears to be more important through Unit 2 and most likely represents material derived from the western Laptev Sea (drained by the Khatanga River). Thus, major changes in the biogenic system observed during the time of deposition of Unit 2 (Middle Eocene) appear broadly synchronous with a significant change in terrigenous provenance. Although the assignment of sources is constrained by the lack of data from other regions (e.g., eastern Siberian Sea) our data suggest changes in provenance that are linked to paleoceanographic changes in the Arctic Ocean.
DE: 3344 Paleoclimatology (0473, 4900)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting