HR: 0800h
AN: PP11B-0566 [Abstracts]
TI: The Composition and Flux of Terrigenous Material from the late Paleocene to the early Eocene in the
Indian Ocean
AU: * Nicolo, M J
EM: micahn@rice.edu
AF: Rice University Earth Science, 6100 Main St., MS-126, Houston, TX 77005
United States
AB:
Stable isotope records of both marine and terrestrial origin constructed from numerous widespread locations show a
characteristic sequence of large amplitude variations in \delta $^{18}$O and \delta $^{13}$C between ca. 60 and 50 Ma,
suggesting major changes in global climate and carbon cycling from the late Paleocene to the early Eocene. Continental
weathering and atmospheric circulatory systems should have varied in response to these global fluctuations. In this regard,
the flux, composition and grain-size of both eolian and hemipelagic (terrigenous) components of oceanic sediments should be
affected by the intensity of atmospheric circulation and changes in terrestrial climate and weathering respectively. Deep-Sea
Drilling Project Site 215 (near Ninety-East Ridge), Ocean Drilling Program Site 752 (Broken Ridge), and Ocean Drilling
Program Site 762 (Exmouth Plateau) are located in the Indian Ocean, have well-dated early Paleogene sections, and are
applicable to these systems in different ways (e.g. are varied by latitude and type of terrigenous material they likely
received during the time interval of interest). Following early work at ODP Site 215 (Hovan and Rea, 1992), here we present
records of the terrigenous component at these sites, including mass accumulation rate (MAR), grain-size, and mineralogy
(XRD). These records coupled with future work in the southern Atlantic and southern Pacific oceans provide a basis for
understanding early Paleogene climate changes in the Southern Hemisphere, as well as constraints for future modeling.
DE: 4267 Paleoceanography
DE: 3022 Marine sediments--processes and transport
DE: 1886 Weathering (1625)
DE: 1620 Climate dynamics (3309)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting