Evolution of drainage systems and its developing trend in connection with tectonic uplift of Eastern Kunlun Mt.

The Eastern Kunlun Mt. had been subjected to uplift together with the Qingh ai-Xizang (Tibet) Plateau before the Early Pleistocene, and yet the Mt. did not protrude out of the Plateau surface. During that period lakes spread a ll over the studied region, with the drainage systems being all short river s flowing into the lakes. At the end of the Early Pleistocene, intensive te ctonic uplift led to the rising of the Eastern Kunlun Mt. and made the Mt. protrude onto the Plateau surface. As a result, a fault depression valley f ormed extending nearly from west to east along the fault belt of the Southe rn Kunlun Mt. Lakes in this region died out, surface runoffs joined into th e valley of the Southern Kunlun Mt. resulting in a large river streaming ne arly from west to east. Around 150 kaBP, because of the strong differential movement, rivers, such as the Jialu River and the Golmud River, retrogress ively eroded seriously, cutting through the Burhan Budai Mt. Then they pira ted the large river and divided it into four portions. Owing to the uplift of the Eastern Kunlun Mt., strongly retrogressive erosion of the upper reac hes of the Jialu River has made the watershed of the Buqingshan Mt. migrate 6-10 km southward since Holocene. At present, it remains a stronger trend of retrogressive erosion developing upward to the basin of the Yellow River Source and it seems that the Jialu River is scrambling for the streamhead of the Yellow River.