Climate changes at millennium scale in East Asian monsoon during OIS3a in Badain Jaran Desert, China

Abstract

The CGS3a from the Chagelebulu section locates southeast of China’s Badain Jaran Desert. This area includes 5.5 sedimentary cycles that consist of lacustrine facies and eolian dune sands or loess during the OIS3a. Based on analyses of contents of Rb and Sr and ratios of Rb/Sr in the CGS3a, along with particle Mz (Φ) and σ, the values of contents of Rb and Sr and ratios of Rb/Sr in the dune sands or loess are lower than those in the lacustrine facies, showing 5.5 fluctuations, which are similar to the sedimentary cycles in the CGS3a segment. Therefore, the CGS3a segment reveals 5.5 warm–wet and cold–arid climate cycles that are controlled by the East Asian winter and summer monsoons in the OIS3a. This trend suggests climate changes at the millennium scale in the East Asian monsoon in the desert areas of China during the OIS3a period. Among those changes, the cold periods correspond well to the Heinrich Events, and warm periods are consistent with the Dansgaard–Oeschger events in the Greenland ice-core project. The millennium-scale climate variation in the East Asian monsoon is the actual regional response to the global climate variations during the OIS3a period.