LATE QUATERNARY GLACIATIONS OF MUSHTAGATA AND MT. KONGUR IN SEMI-ARID REGION OF NORTHWESTERN TIBET FROM COSMOGENIC 10BE EXPOSURE DATING

The glaciation in Tibet and the Himalaya is essentially controlled by two major climatic systems; the mid-latitude westerlies and south Asian summer monsoon. To help resolve the relative importance of these climatic systems, we studied two massifs in northwestern Tibet, Mushtagata and Mt. Kongur, of which present day climates are influenced solely by the mid-latitude westerlies and is beyond the influence of the monsoon. Remote sensing, geomorphic mapping and cosmogenic Be-10 surface exposure dating of boulders on the moraines indicates that the glaciers of Mushatagata at 41-125ka, 17-71Ka, 17.8ka, 13.7ka, 10.5 ka, 8.2ka 6.5 ka, 4.5 ka, 1.8 ka and Little Ice Age. The temporal variations of glaciations of in this region are not in phase with other areas of the Tibetan Plateau that are dominantly affected by Indian Summer Monsoon, but are broadly synchronous with Northern Hemisphere. Interestingly, our data shows that glaciations in the semi-arid northwestern Tibet since Last Glacial Maximum are likely linked to Northern Hemisphere cooling events (Rapid Climate Changes) by Mid-latitude Westerlies.