HR: 1340h
AN: U13B-1153    [Abstracts]
TI: A Younger Dryas glacierization in the Venezuelan Andes
AU: * Stansell, N D
EM: nas12@pitt.edu
AF: University of Pittsburgh, Department of Geology and Planetary Science, 4107 O'Hara Street, Rm 200 SRCC, Pittsburgh, PA 15260, United States
AU: Abbott, M B
EM: mabbott1@pitt.edu
AF: University of Pittsburgh, Department of Geology and Planetary Science, 4107 O'Hara Street, Rm 200 SRCC, Pittsburgh, PA 15260, United States
AU: Polissar, P J
EM: ppolissa@geosc.psu.edu
AF: The Pennsylvania State University, Department of Geosciences, University Park, State College, PA 16802, United States
AU: Bezada, M
EM: mbezada@cantv.net
AF: Departamento de Ciencias de la Tierra, Universidad Pedagógica Experimental Libertador, Avenida Paez, El Paraíso, Caracas, 99999, Venezuela
AB: The Younger Dryas (YD) was an abrupt climate change event that has been well recorded in marine archives, but is still uncertain in terrestrial records from the tropics. For instance, the YD is recorded in the Cariaco Basin as an event of increased upwelling intensity and decreased terrigenous input; however continental records of a coincident climate change event across the region are inconclusive. Moreover, pollen data from the Colombian Andes suggest that there was a local cold stadial that coincides with the YD, but paleoenvironmental records from the Venezuelan Andes during the same time interval are not clear. Here we present a high-resolution late- glacial sequence from the Pico Espejo region of Venezuela. Our record is based on radiocarbon dated lake sediments that were analyzed using magnetic susceptibility, scanning X-ray fluorescence and loss-on-ignition methods. The sequence contains a period of increased glacial-sedimentary flux between ca. 13,000 and 12,000 cal yr BP, which coincides with the timing of the YD. Glacio-lacustrine sediments also increased between ca. 11,000 to 10,000 cal yr BP. Combined, these data suggest the northern tropical Andes experienced cooling events during the YD, and from ca. 11,000 to 10,000 cal yr BP.
DE: 0720 Glaciers
DE: 1605 Abrupt/rapid climate change (4901, 8408)
SC: Union [U]
MN: 2007 Fall Meeting