Features of the glaciation during the Last Glaciation in northwestern Yunnan Province

Investigation of Quaternary glaciation in the mountains in northwestern Yunnan Province,ranging from 4 000 to 4 500 m a. s. l.,indicates that the glaciation mainly depended on the planation surface from 4 000to 4 300 m a. s. l. Glaciers were small ice caps and valley glaciers during the early and middle stages,and limited cirque glaciers during the late stage of the Last Glaciation. Glacial advance mainly took place during the Last Glaciation. Analyzing the equilibrium line altitudes in the Last Glaciation,summits of the mountains and the planation surface altitudes indicates that the planation surfaces,on which glaciers in the Last Glaciation depended,were 50- 400 m higher than ELA. The altitude between 4 000 and 4 500 m provided the beneficial height for the glaciers development. Analyzing the evolution of glacial extent shows that the glacial extent during the middle of MIS 3 was larger than that in the Last Glaciation Maximum( LGM). It is believed that the glacial advance during the MIS 3 was due to both plentiful precipitation and lowtemperature. Data of paleo-temperature and paleoprecipitation and Quaternary glaciation investigation reveal that the Last Glaciation was resulted from climate change and tectonic movement.