Abstract:
The Quaternary of the Qaidam basin is a successive and complete accumulation of fluvial-lacustrine sediments with a great thickness. Based on a study of Quaternary sporopollen assemblages and their vertical distribution at typical profiles of holes ZK701+801, Shui 6, Sezhong 6 and Seshen 1, this paper discusses in detail Quaternary assemblage zones and the vegetation and climatic evolution represented by them. A highly precise sporopollen climate curve is obtained, which shows that alternation of dry-cold and wet-warm climates is the basic model of the Quaternary paleoclimate evolution in the Qaidam basin. Altogether 59 sporopollen assemblage zones and 29 complete cold-warm paleoclimatic cycles since 1.87 Ma B.P. have been recognized. They can be well correlated with the 37 paleoclimate cycles derived from Quaternary loess and paleosols in northwestern China and the deep sea oxygen isotope climate records.