HR: 0800h
AN: GC51C-1059    [Abstracts]
TI: The Lake Peten-Itza (Guatemala) Drilling Project: Tracking Late Quaternary Environmental Change in the Lowland Neotropics
AU: * Anselmetti, F S
EM: flavio.anselmetti@erdw.ethz.ch
AF: ETH-Zurich, Geological Institute, Sonneggstrasse 5, Zurich, 8092 Switzerland
AU: Hodell, D A
EM: dhodell@geology.ufl.edu
AF: University of Florida, Department of Geological Sciences, PO Box 112120, Gainesville, FL 32611 United States
AU: Ariztegui, D
EM: daniel.ariztegui@terre.unige.ch
AF: University of Geneva, Institute F.- A. Forel 10, route de Suisse, Versoix, 1290 Switzerland
AU: Brenner, M
EM: brenner@ufl.edu
AF: University of Florida, Department of Geological Sciences, PO Box 112120, Gainesville, FL 32611 United States
AU: Curtis, J H
EM: curtisj@ufl.edu
AF: University of Florida, Department of Geological Sciences, PO Box 112120, Gainesville, FL 32611 United States
AU: Haug, G
EM: haug@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Section 3.3, Telegrafenberg, C 324 , Potsdam, D-14473 Germany
AU: Hillesheim, M
EM: mbhilles@ufl.edu
AF: University of Florida, Department of Geological Sciences, PO Box 112120, Gainesville, FL 32611 United States
AU: McKenzie, J A
EM: sediment@erdw.ethz.ch
AF: ETH-Zurich, Geological Institute, Sonneggstrasse 5, Zurich, 8092 Switzerland
AB: During the last glaciation, all shallow lake basins in the northern lowland Neotropics were dry because of increased aridity and/or lowered sea level Consequently, no long continous paleoclimate records have yet to be recovered from this climatically sensitive region. Detailed seismic surveys of Lake Peten-Itza have revealed that Lake Peten-Itza is deep (160 m) and possesses a thick ($>$100 m) stratigraphic record that extends back to at least Marine Isotope Stage 5. It is the only lake known to us from the region that is deep enough (160 m) to have held water continuously through the latest Pleistocene. We have therefore proposed this lake as a potential drilling target for the International Continental Drilling Project (ICDP). The objective of the Peten-Itza Drilling Project is to recover continuous, high-quality sediment cores and pore fluids that will be used to test hypotheses related to three broad scientific themes: 1.) Paleoclimatic history of the northern lowland Neotropics on orbital to suborbital time scales emphasizing the correlation of terrestrial-marine-ice core archives (e.g., Cariaco Basin, Greenland ice cores, etc.) 2.) Paleoecology and biogeography of the Maya tropical lowland forest including the history of vegetation change and disturbance by humans, climate change, and fire. 3.) Biogeochemical cycling in deep lake sediments emphasizing integrated studies of microbiology, geochemistry (interstitial waters), and mineral authigenesis/diagenesis. Six primary and four alternative drilling sites have been identified that fall along a depth transect extending from $\sim$30 m to near the deepest point ($\sim$150 m) in the lake. A sequence stratigraphic approach will be employed to constrain the vertical range of past lake level variations for glacial, interstadial, and interglacial stages during the late Pleistocene. The integration of seismic profiles and a depth transect of Kullenberg cores have proven to be an effective strategy for defining lake level during the last glacial period and reconstructing paleoclimate and paleoenvironmental change for the most recent glacial-to-interglacial transition. The basal age of the sections to be drilled is not certain but based on extrapolation of dates for the shallow seismic stratigraphic units, we estimate that deeper sequences should extend through the last interglacial (MIS 5). An international team of research scientists has been assembled to produce a comprehensive suite of paleoenvironmental and biogeochemical measurements on the cores and pore fluids recovered from Lake Peten-Itza. Details of the drilling strategy, site locations, and site survey data can be found on the Peten-Itza Drilling Project website.
UR: http://plaza.ufl.edu/hodell
DE: 3344 Paleoclimatology
SC: Global Climate Change [GC]
MN: 2004 AGU Fall Meeting