Evolution of Palaeo-drainage System and Its Relationship with the Formation of Desert Landform in the Kumtag Desert
库姆塔格沙漠古水系变迁与沙漠地貌的形成

After surveying the Kumtag Desert,the evolution of palaeo-drainage system and its relationship with the formation of desert landform in the Kumtag Desert were studied using survey data,by combining remote sensing images with 1:100,000 scale topographic map and literatures.Some preliminary conclusions were obtained,that is,after the intense uplift of the Altun Mountains in the early Quaternary,a mass of deposition were denuded and conveyed by flood and accumulated on the northern piedmont of the Altun Mountains.The process of accumulation increased not only the depth of the pluvial fan but also lifted its anterior elevation,resulting in eastward deflexion of the palaeo-drainage system,due to lower elevation in the eastern side.After stabilization of the uplift of the Altun Mountains,the flood eroded the pluvial fan,and the gullies,such as Hongliu,Xiaoquan,Suosuo and so on were formed.On the basis of fluviation,the unique desert landscape such as plumed dunes had been formed through intensive wind erosion.The widespread gravel reliefs occurring in desert were constructed by flood events in a relatively short period of time.In addition,the lacustrine sediments appeared at 840 m above sea level reveals that Lop Nur was once connected with Hala lake by Aqik valley.After lake shrinkage,the ancient Shule river and floods from the northern hills gullied the lacustrine sediments from east and north respectively,and two groups of almost vertical Yardang landforms were shaped by wind erosion.