Garz Loess and the Evolution of the Cryosphere on the Tibetan Plateau
Fang Xiaomin 1,Chen Fubin 2 ,Shi Yafeng 3 and Li Jijun 1 (1Department of Geography, Lanzhou University, 730000;2Chengdu Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, 610041;3Nanjing Institute of Lake and Geo
Magnetic polarity dating of a 86 m loess section at Garze on the southeastern Tibetan Plateau demonstrates that the bottom of the section was formed 818.4 ka BP. Analysis of various quartz sands in the section indicates that the plateau uplifted above snow line and began to develop glaciers at least 818.4 ka BP. ago. Soon late (c. 760 ka BP), glaciers reached their maximum, which are also largest in the scale during 818.4 ka BP., and may persist to about 530 ka BP. The second largest glaciation developed during the penultimate. Since the penultimate, the scale of glaciers has decreased greatly. The analysis also suggests that air circulation and environment occurred sharp changes or adjustments and enhancement at about 818.4 ka BP, 655 ka BP and 175 ka BP. They might be the results of accompanied environmental abrupt changes at some critical heights of the plateau with the sudden uplift.