Pollen and grain size characteristics recorded from evaporite in the Kumishi Basin in arid Central Asia: implications for climate and environmental change since the late glacial

Abstract

Climatic and environmental changes in the arid region of Central Asia since the late glacial period have long been a research focus. This study investigated the 200 cm evaporite profile in the Kumishi Basin, an inland Salt Lake situated in the arid region of Central Asia. By utilising AMS¹⁴C dating and examining the relationship between pollen and grain size, this study analysed the paleoclimate and related paleoenvironmental changes. Based on the dating results and the characteristics of pollen and grain size, it was deduced that the Kumishi Salt Lake formed prior to 11.6 cal ka BP. Although the climate was initially humid, the dominant conditions in this area were mainly arid, featuring desert and desert vegetation environments. Between 11.6 and 6.0 cal ka BP, the vegetation primarily consisted of desert steppe, while the climate remained predominantly dry with a minor period of humidity in the early stages of the Holocene. From 6.0 to 0 cal ka BP, desert grasslands continued to dominate the landscape as the climate gradually intensified in aridity. These climate fluctuations in the Kumishi Salt Lake area exhibited distinct regional characteristics after the late glacial period. Compared to the monsoon system, the climate of the study area was more likely influenced and controlled by the westerlies, as particularly evidenced by the dry environment during the Holocene period.