青藏高原（格尔木-亚东）冰缘现象及其气候意义

Based on evidences of periglacial landforms and deposits along Golmud and Yadong，and age con⁃ straint，this paper discusses the environmental characteristics of periglacial evolution on the North-South section of the central Qinghai-Tibet Plateau since the Last Glacial period. The evidences at Golmud show in LGM，the permafrost reaches at least 2 900 m above sea level，the annual average temperature drops to < -4 ℃，which was at least 9 ℃ lower than the present，and the climate is cold and dry；there are extremely dry and cold climate events in the deglaciation period and Holocene，and there may be a rapid cooling climate period in winter when the ground temperature was less than -10 ℃. The Ice wedge pseudophorms at Qumar River，Gulu（Naqu），and Nam Co recorded permafrost expansion during the Last Glacial period. The relict ice wedge at Yadong recorded early Holocene cold events. Palynological and dating evidences of the peat section at Yangbajing indicate that the area has experienced four climatic stages since the Younger Dryas event：severe cold（12. 8~9. 8 ka），warm and humid（9. 8~5. 0 ka），dry and cold（5. 0 ka to present）. The widely developed involutions，stratified slope deposits and eolian deposits in the study area are important evidences have the value of depicting temperature and precipitation variation for paleoenvironment reconstruction.