Climate evolution since 9.32 cal ka BP in Keluke Lake, northeastern Qaidam Basin, China

Abstract

Core sediments from Keluke Lake in transitional zone between arid central Asia and monsoon Asia, provide insights into the advance-retreat history of the summer monsoon and the Westerlies. Sediment grain size and δ13C of authigenic carbonate reveal paleoclimatic evolution since 9.32 cal ka BP: a dry-cold climate in the early Holocene, a wet-cold climate in the early stage of mid-Holocene, a relatively dry-warm climate in the late stage of mid-Holocene and, a moderately wet and frequently oscillating climate after 2.5 cal ka BP. Keluke Lake was mainly controlled by the Westerlies from 9.32 to 5.8 cal ka BP, and was dominated by the East Asia monsoon during 5.8–2.5 cal ka BP. While in the late Holocene, this area was re-controlled by the Westerlies since 2.5 cal ka BP. The boundary line between the Westerlies controlled arid central Asia and monsoon Asia varied during the Holocene. When the Westerlies strengthened and the East Asian summer monsoon weakened, the boundary line may be pushed southeastward, and vice versa. Generally, the climate in this area showed a wet-cold and dry-warm variation.