LACUSTRINE RECORDS OF HOLOCENE CLIMATE CHANGE FROM LOP NOR SALT PLAIN, TARIM BASIN, WESTERN CHINA

Lop Nor salt plain, located in Xinjiang Province, western China, is one of the largest internally draining systems in the world. Lop Nor is the terminal lake of the Tarim Basin, China’s largest endorheic basin with an area greater than 530,000 km². Little is known about the climate history of the Tarim basin region in general or Lop Nor salt plain in particular. Here we present chronological, sedimentological, geochemical, geophysical and pollen data from a 2-meter-long sediment core from the Lop Nor basin, which are used to interpret the evolution of environments and climate during the Holocene. Our data demonstrate that Lop Nor was an ephemeral fresh-to-brackish lake in the early Holocene, and dried up into a saline mudflat ~9000 yr Bp, as indicated by massive grey-green muds containing intrasediment gypsum crystals. There was a drought period ~8100 yr BP, that resulted in the precipitation of halite and gypsum from hypersaline waters. A humid climate returned ~ 6725 yr BP, marked by clastic and carbonate sediments. Near ~3800 yr BP, the hyper-arid climate returned and Lop Nor evolved from a brackish lake to a salt lake to the present-day saline pan. A number of these events correspond with changes in cultural periods, suggesting that climate was a key mechanism affecting human occupation of this region.