Northeastern Section - 54th Annual Meeting - 2019

Paper No. 52-1
Presentation Time: 8:00 AM-12:00 PM

A 10BE CHRONOLOGY OF MORAINES DEPOSITED DURING THE LOCAL LAST GLACIAL MAXIMUM IN THE SHALULI SHAN, SOUTHEASTERN TIBETAN PLATEAU, SICHUAN PROVINCE, CHINA


MATTAS, Laura Alexandra1, STRAND, Peter D.1, PUTNAM, Aaron E.1, LINDSAY, Benjamin P.1, RADUE, Mariah J.1, ZHOU, Weijian2 and AN, Zhisheng2, (1)School of Earth & Climate Sciences / Climate Change Institute, University of Maine, Bryand Global Sciences Center, Orono, ME 04469, (2)State Key Lab of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China

Identifying the mechanisms that produced global cooling at the peak of the last ice age will aid in the general understanding of ice-age climate dynamics. This problem can be addressed by developing a global network of mountain glacier reconstructions, all underpinned by detailed glacial geomorphic mapping, accurate and precise landform chronologies, and quantitative glaciological modeling. Here, we address a piece of this puzzle by presenting a glacier chronology for the local Last Glacial Maximum from the southeastern Tibetan Plateau. This region features exceptionally well-preserved morainal landscapes that afford a test of various mechanisms for high-altitude ice-age cooling. Here, we target a set of moraines deposited by a glacier that emanated from the Shaluli Shan mountains, southeastern Tibetan Plateau, Sichuan Province, China (30°N, 100°E). We present a 10Be surface-exposure chronology that documents the timing of glacier fluctuations that define the local Last Glacial Maximum in this region. Our initial results indicate that glaciers in this region achieved maxima in concert with the global glacial maximum, at a time when East Asian monsoon strength was relatively weak. We interpret these results to indicate that temperature, and not local precipitation, was the dominant factor controlling glacier mass balance in southeastern Tibet.