Northeastern Section - 44th Annual Meeting (22–24 March 2009)

Paper No. 8
Presentation Time: 1:00 PM-5:00 PM

LATE QUATERNARY GLACIAL CHRONOLOGY NEVADO ILLIMANI, CORDILLERA REAL, BOLIVIA: IMPLICATIONS FOR PALEOCLIMATIC RECONSTRUCTIONS ACROSS THE ANDES


SMITH, Colby A., Geology, St. Lawrence University, 23 Romoda Drive, Canton, NY 13617 and LOWELL, Thomas V., Geology, University of Cinncinnati, Cincinnati, OH 45221, casmith@stlawu.edu

New 10Be surface exposure ages from moraines on Nevado Illimani, Cordillera Real, Bolivia suggest that glaciers retreated from moraines during the periods 15.0 ka -13.0 ka; 10.5 ka - 8.5 ka, and 3.0 ka - 1.5 ka. Late Glacial moraines at Illimani are associated with an ELA depression of ~400 m, which is consistent with other local reconstructions of Late Glacial ELAs in the Eastern Cordillera of the central Andes. Reconstructed ELA gradients across the Andes based on dated Late Glacial moraines suggest a change in slope of the regional ELA that is consistent with increased precipitation from the west.