HR: 14:25h
AN: U23A-04    [Abstracts]
TI: The Last 1 Million Years at Tenaghi Philippon: Terrestrial, Marine and Ice Core Comparisons
AU: * Tzedakis, P C
EM: p.c.tzedakis@leeds.ac.uk
AF: Earth and Biosphere Institute, School of Geography, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT United Kingdom
AU: Hooghiemstra, H
EM: hooghiemstra@science.uva.nl
AF: Institute for Biodiversity and Ecosystem Dynamics (IBED), Research Group Palynology and Paleo/Actuo-ecology, Faculty of Science, University of Amsterdam, Kruislaan 318, Amsterdam, 1098 SM Netherlands
AU: Wijmstra, T A
AF: Institute for Biodiversity and Ecosystem Dynamics (IBED), Research Group Palynology and Paleo/Actuo-ecology, Faculty of Science, University of Amsterdam, Kruislaan 318, Amsterdam, 1098 SM Netherlands
AB: Palaeoenvironmental archives spanning multiple glacial-interglacial cycles provide a unique perspective into the evolution of Quaternary climate variability. However, while marine and ice core records may furnish the best estimates of global climate variability, we still remain in relative ignorance as to how these changes translate to events on land, because of a shortage of suitable terrestrial sequences and inadequate chronological control. Continuous, pollen-bearing lake sediment sequences are found only in exceptional circumstances and a handful of these occur in S. Europe. Here we examine the longest of these records, from Tenaghi Philippon (TP), northeast Greece, spanning the last 1 million years. A new astronomical calibration procedure, based on a correspondence between changes in certain vegetation elements and March and June perihelion configurations, is applied to the entire section, leading to a revised timescale especially for the lower part of the sequence. The TP sequence shows a close correspondence between marine and terrestrial stages over the last million years, although individual boundaries may not be precisely isochronous. However, inspection of the record reveals a significant departure in terms of the amplitude of glacial-interglacial variability, with the onset of more extreme interglacials occurring after MIS 16, rather than MIS 12 as seen in marine and ice core records. More specifically, TP interglacials before MIS 16 are characterized by lower arboreal pollen increases, as a result of sustained presence of grasses. Part of this grass signal is derived from local semi-aquatic vegetation, suggesting increased marsh area and lower water levels. This may be a function of local factors (e.g. tectonic changes) altering the hydrological regime of the Philippi plain. Alternatively, the occurrence of a shift in interglacial amplitudes right at the MIS 16/15 transition, may suggest a climatic control. Comparisons with other records are needed in order to establish the local or regional character of such changes.
DE: 3344 Paleoclimatology
DE: 4267 Paleoceanography
DE: 1600 GLOBAL CHANGE (New category)
SC: Union [U]
MN: 2004 AGU Fall Meeting