HR: 0800h
AN: OS11A-0184    [Abstracts]
TI: Late Paleocene- Early Eocene paleoenvironments in the Southwest Pacific (ODP Leg 189): Revised Stratigraphy of an Antarctic PETM Record.
AU: Bijl, P K
EM: p.k.bijl@students.uu.nl
AF: Laboratory of Palaeobotany, and Palynology, Utrecht university, Budapestlaan 4, Utrecht, 3584 CD, Netherlands
AU: Brinkhuis, H
EM: h.brinkhuis@uu.nl
AF: Laboratory of Palaeobotany, and Palynology, Utrecht university, Budapestlaan 4, Utrecht, 3584 CD, Netherlands
AU: * Sluijs, A
EM: a.sluijs@uu.nl
AF: Laboratory of Palaeobotany, and Palynology, Utrecht university, Budapestlaan 4, Utrecht, 3584 CD, Netherlands
AU: Reichart, G
EM: reichart@geo.uu.nl
AF: Department of Earth Sciences ¡V Geochemistry, Utrecht University, Budapestlaan 4, Utrecht, 3584 CD, Netherlands
AU: Schouten, S
EM: schouten@nioz.nl
AF: Royal Netherlands Institute of Sea Research, Landsdiep 4, Den Hoorn, Texel, 1797 SZ, Netherlands
AU: Röhl, U
EM: uroehl@rcom-bremen.de
AF: Center for Marine Environmental Sciences (MARUM, Bremen University, Leobener Straße, Bremen, 28359, Germany
AB: The Late Paleocene and Early Eocene (~60 ¡V 50 Ma) were characterized by globally warm climates. Superimposed on this general warmth, several episodes of further warming occurred (so-called hyperthermals), including the Paleocene-Eocene thermal maximum (PETM, ~55 Ma) and Eocene thermal maximum 2 (ETM2, ~53 Ma). While the PETM is by now well documented from Northern Hemisphere, and some equatorial locations, southern high-latitude records are still rare. Here we present high-resolution palynological, XRF, bulk organic stable carbon isotope (ƒÔ13CTOC), and TEX86 palaeothermometry data across Upper Paleocene through Lower Eocene pro-deltaic deposits from the Southwest Pacific Ocean, at ~65¢XS palaeolatitude (ODP Site 1172). Based on a revised integrated biomagnetostratigraphic age model and ƒÔ13CTOC stratigraphy, we identify the southernmost marginal marine PETM ever encountered. Moreover, there is every indication that ETM2 was recovered as well at Site 1172. Despite a high latitude source of the surface waters at this site, the PETM is marked by the characteristic acme of representatives of the (sub) tropical dinoflagellate cyst (dinocyst) Apectodinium, confirming the truly global nature of this PETM event. TEX86 values indicate that surface ocean temperatures rose from ~23¢XC to ~30¢XC during the PETM at Site 1172, hence by a similar magnitude as recorded in other PETM successions globally. Before and after the CIE, mass abundances of low salinity tolerant dinocysts are recorded, taken as indicative of increased runoff. These trends are analogous to those recorded at northern high latitudes, indicating a similar climate response at both polar regions during the PETM. Yet, some distinct differences are apparent, and are discussed.
DE: 0459 Macro- and micropaleontology (3030, 4944)
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 1055 Organic and biogenic geochemistry
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1630 Impacts of global change (1225)
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting