Geomorphic Characteristics of Periglacier in the Source Area of Yellow River in Qinghai-Xizang Plateau,China
Bian Chunyu and Guo Pengfei (906 Hydrogeologic and Engineering Geologic Team Ministry of Geology and Minerais)
The source area of Yellow River with an average elevation of more than 4 000 metres, is situated in the northeastern part of Qinghai-Xizang Plateau. (34°00 ' -35°40' N and 97°00 '-99°40 ' E). There widely occur stretches of permafrost at more than 3 800-4 200 metres above sea level. The geomorphology of periglacier develops quite well, including frozen disintegration geomorphology, freezing and thawing geomorphology in cold environments, buried ices and fossil periglacial phenomena. Various periglacial geomorphological features in the source area of the Yellow. River are firstly discussed in detail in this paper. In light of the relation between stratigraphy and periglacial phenomena, period three perigacial can be divided, which are the middle pleistocene periglacial period, the late pleistocene glacial margin period and modern ice margin period.