Last Glaciation and Maximum Glaciation in Qinghai-Xizang Plateau--A Controversy to M. Kuhle Ice Sheet Hypothesis
Shi Yafeng, Zheng Benxing and Li Shijie (Lanzhou Institute of Glaciology and Geocryology, Chinese Academy of Sciences)
Since the late 1950's, a lot of Chinese scientists explored the remain of Quaternary Glaciation in Qinghai-Xizang Plateau and its surrounding mountains, 3-4 glaciations were primarily recognized. The largest one occurred in late Middle Pleistocene with piedmont glaciers, ice caps and trellis valley glaciers in many high peak regions. But no evidences of unit ice sheet covered the whole plateau as described by M. Kuhle. Due to the further uplifting of the Himalayas and Qinghai-Xizang Plateau the climate become drier and drier, diminished the extension of glaciers during Late Pleistocene. The elevation of the snowline during last glaciation was about 4 000 m in south, east and northeast margins of the plateau and ascended to 5 500 in in northwest part of inland plateau. The thermal effect of the big plateau mass, the great increasing of aridity from southeast margin to northwest inland area and the abrupt decreasing of precipitation during Ice Age induce the distribution features of Quaternary glaciers in Qinghai and Xizang Plateau. The neglect of Chinese literature may be one cause of M. Kuhle's misinterpretation on the environment,of Quaternary Glaciations in Qinghai-Xizang Plateau.