GLACIERS AT THE SOURCE REGION OF TUOTUO RIVER IN THE UPPER REACHES OF THE CHANGJIANG AND THEIR EVOLUTION
Zhang Linyuan ( Department of Geology and Geography, Lanzhow University )
This region is situated at the western end of Tanggula Mountain and belongs to the interior of Qinghai-Xizang Plateau. Owing to the mountains being very high and the planation surface being comparatively perfect above the firnline,both the scale and the concentration of glaciers are the greatest in the interior of Qinghai-Xizang Plateau as well as in Tanggula Mountains as a whole, though the climate in this region is extremely continental. Evidences have proved that there are three Ice Ages(possibly corresponding to Mindel, Riss and Wurm glaciations) .Since the Riss glaciation, the mountain bodies of this region have been continuously lifting,but the scale of glaciation was successively shrinking smaller and smaller.This is dueto the general tendency of the climatic changec in the interior of the Plateau with a continuous strengthening of desiccation.