Late Cenozoic Geology and Paleo-environment Change in the Eastern Edge of Qinghai-Xizang Plateau

There are late Cenozoic lacustrine deposits and loess and red clay and moraines in eastern edge of the Qinghai-Xizang Plateau.Various genetic sediments recorded rich information on late Cenozoic paleo-environment changes.Xigeda lacustrine formed during 4.2 Ma B.P.-2.6 Ma B.P.There were 9 periodic warm-cold alternations.Eolian deposition in western Sichuan began at 1.15 Ma B.P. The loess-soil sequences recorded successively 14 paleo-monsoon climate cycles.Laterite in Chengdu plain recorded 5 stages of paleoclimatic stages since 1.13 Ma B.P.There was an old glacial period of 4.3 Ma B.P.in eastern Qinghai-Xizang Plateau.During Quaternary,there are 5 extreme paleoclimatic events corresponding with 5 glaciations.