Lake Transgression and Reasons during Last Glaciation Maximum on the North Margin of Qinhai-Xizang Plateau
Li Shuanke (Institute of Geography, Chinese Academy of Sciences and State Planning Commission, People's Republic of China) Li Shijie (Lanzhou Institute of Glaciology and Geocryology, Chinese Academy of Sciences)
Recently it has been discovered that many lakes on the north margin of Qinhai-Xizang Plateau had expanded during Last Glaciation Maximum, around 18 000 a B.P., and the lake level was 10-40 m higher than that at present. The lake transgression started and evded earlier in the west part than that in the east part of the plateau. The reasons of lake transgression during Last Glaciation Maximum are related to the increase of ice and snow melt-water in warm season and to the reduction of lake evaporation. The discovery of lake transgressional stratigraphy has important theoretioal significance for recorgnizing and evaluating the role of Qinhai-Xizang Plateau in Global environmental changes.