HR: 1340h
AN: PP13B-1288    [Abstracts]
TI: Deglaciation in the High Andes – a Record from Laguna Piuray (Cusco, Peru)
AU: Nederbragt, A
EM: a.nederbragt@ucl.ac.uk
AF: Department of Earth Sciences, UCL, Gower Street, London, WC1E 6BT, United Kingdom
AU: * Thurow, J
EM: j.thurow@ucl.ac.uk
AF: Department of Earth Sciences, UCL, Gower Street, London, WC1E 6BT, United Kingdom
AU: Brumsack, H
EM: brumsack@icbm.de
AF: IBCM, Oldenburg, PO Box 2503, Oldenburg, D-26111, Germany
AU: Lowe, J
AF: Department of Geography, RHUL, Egham, TW20 0EX, United Kingdom
AU: Pearce, R
EM: rp1@noc.soton.ac.uk
AF: NOC, Southampron, University of Southampton, European Way, Southampon, EH9 3ZH, United Kingdom
AU: Ramsey, C
EM: hristopher.ramsey@rlaha.ox.ac.uk
AF: RLAHA, University of Oxford, South Parks Road, Oxford, OX1 3QY, United Kingdom
AB: The Peruvian Andes lie in a crucial location for paleoclimate investigation. Fluctuating Pacific and Atlantic air masses compete for long-term dominance of the region, with the El-Nino Southern Oscillation (ENSO) system causing further variability. A laminated glacial/interglacial sediment sequence (6m) exposed around the shores of Laguna Piuray, near Cusco, offers not only the potential to reconstruct the climate history of the area but also to test for strength and frequency of the Atlantic monsoonal and Pacific ENSO influence. A suite of continuous cores was collected from deep trenches. The sedimentary record is characterized by postglacial diatom-rich chalk overlying organic-rich clayey chalk. Between these units are 3 distinct organic layers (80% TOC) deposited between 12-14 cal. kyr BP (14C). The base of the record is probably as old as 25kyrs (U/Th). We obtained a multi- proxy record of the section including continuous XRF scanning data of the entire sequence, and stable isotopes, XRF, XRD, TOC, biogenic opal, and carbonate analysis of discrete samples as well as a relative paleotemperature record from analyses of soil biomarkers. All the data profiles we obtained show a pronounced increase in temperature and decrease in precipitation at 13.8kyrs and are in good correlation with published regional Andean records using single proxies. Our results confirm that the Deglaciation Cold Reversal in central South America is not identical to the Younger Dryas event in the Northern Hemisphere.
DE: 4901 Abrupt/rapid climate change (1605)
DE: 4914 Continental climate records
DE: 4926 Glacial
DE: 4936 Interglacial
DE: 4942 Limnology (0458, 1845, 4239)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting