Abstract: Gobi desert covers a large area of northwestern China, but few studies are undertaken on its formation and evolution. Palaeoenvironmental change of the Gobi deserts in front of Northern Altun Mountains are recorded by alluvial deposits. Based on optically stimulated luminescence (OSL) dating the Shanshuigou section record which is close to the Nan Hu oasis of Dunhuang in Gansu province, as well as investigations such as grain size, magnetic susceptibility and organic carbon isotopic composition, the Gobi depositional environment variation since in 5 000 yrs BP was examined. Results show that the evolution of the Gobi deserts are of fluctuation and the sedimentary dynamics are affected by climatic change at centennial to millennial time scales. Sediment transport capacity was weaker during 2 670-3 570 yrs BP and 1 650-1 950 yrs BP because of the dry and warm climate, and thus the Gobi desert was shrunk. On the other hand, the transported processes were enhanced as a result of increased river discharge during 4 270-4 840 yrs BP. These results unravel the linkage between landform evolution of the Gobi deserts and climatic change during the late Holocene.

Key words: Northern Altun Mountains, Holocene, Gobi evolution, depositional dynamics, climate change