Piedmont river terraces formation of the western Kunlun, China and their tectonic significance.

There are six levels of alluvial terraces in the piedmont area of western Kunlun. Dating tests are carried out by optical stimulated luminescence (OSL) and thermoluminescence (TL) method on lower terraces accumulates of several major rivers. It shows that the formation of these terraces happened in the same period, and the tectonic activity is the major controlling factor of the terraces. The age dating of river terraces shows that the river terraces formed at least at about 1.2Ma on the western Kunlun piedmont. The T4, T3 and T2 terraces formed at about 39ka, 18ka and 5ka, respectively. River incision into the actively uplift of the western Kunlun Mountains during the middle Early-Pleistocene time is reflected in the formation of numerous levels of river terraces. The development of river terraces and the regional geological correlation demonstrate that the uplift process of western Kunlun since Late Quaternary. Regional tectonic activity can significantly control river patterns and behavior. According to the distribution, geomorphic characteristics and correlation of river terraces, the formation and evolution of river terraces are controlled by the multiple effects of neotectonic, uplift and climate change.