Monday, 27 August 2007
1.PS-15
A Pleistocene Warming Event at 1 Ma in Prydz Bay, East Antarctica: Evidence from Odp Site 1165
Giuliana Villa1, Claudia Lupi2, Miriam Cobianchi2, Fabio Florindo3, and Stephen F. Pekar4. (1) Dipartimento di Scienze della Terra, Università di Parma, Parco Area delle Scienze, 157A, Parma, 43100, Italy, (2) Dipartimento di Scienze della Terra, Università di Pavia, Via Ferrata 1, Pavia, 27100, Italy, (3) Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, Roma, 00143, Italy, (4) School of Earth and Environmental Sciences, Queens College, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367
Magnetostratigraphic and nannofossil assemblage data from ODP Site 1165 evidence an anomalous warming event of the surface waters in and around Prydz Bay during the Early Pleistocene. This results from an increase in the abundance of nannofossils at Site 1165, that occurred at 1 Ma. High-resolution sampling permits a new bio-magnetostratigraphic interpretation for ODP Site 1165. A decrease in ?18O values at Sites 1165 and 1167 also occurs at this time, supporting the presence of warming conditions in the Prydz Bay area. A return to colder surface waters, indicated by the absence or rare occurrence of nannofossils in the upper cores from Site 1165, suggests that more stable glacial conditions existed in the Prydz Bay basin for the last 900 ka. These new evidences call for a re-evaluation of the notion that the East Antarctic Ice Sheet has experienced stable conditions similar to today since the late Neogene.