Characteristics of River Terraces in North Slope of Eastern Kunlun Mountains and Their Relationship with Plateau Uplift

Abstract

The study on the drainage system in the north slope of the eastern Kunlun Mountains indicates that the E-W trending basin-mountain geomorphology was formed after the Kunlun-Yellow River tectonic movement. This tectonic movement established the early stage of drainage system in which the main river developed along the E-W direction valley. Another important tectonic event, Gonghe tectonic movement, occurred between the Middle Pleistocene and Late Pleistocene, caused the N-S direction rivers to erode quickly southward and capture the drainage system of early stage, when the framework of present drainage pattern was also formed. Then, there was a relatively stable stage during Late Pleistocene. A sequence of thick and large-scale sediments of T5 aged between 52.4 ka and 18.4 ka deposited along most of the rivers during this stage. Since 18.4 ka, the tectonic events in the area have been frequent but with limited intensity. Besides, five terraces were developed after 18.4 ka. The later terraces were upper-overlapping the fifth terrace and did not cut through the deposits of the fifth terrace.