西昆仑山前河流阶地的形成及其构造意义

西昆仑山前河流普遍发育6级阶地，利用光释光（OSL）与热释光（TL）方法对采自西昆仑山前几条主要河流的低阶地堆积物样品进行年代测定。研究结果显示，主要河流低阶地的形成具有同时性，构造活动是河流阶地形成的主要控制因素。河流阶地的年龄测定结果表明，西昆仑山前河流阶地最早形成于约1.2Ma，T4、T3、T2阶地分别形成于约39ka、18ka和5ka。多级阶地的形成反映了河流自早更新世中期开始下切于活动抬升的西昆仑山。河流阶地的发育及区域对比揭示了西昆仑第四纪晚期以来的隆升过程，区域构造活动明显地影响河流的形态与行为。河流阶地的分布、地貌特征及区域对比表明，河流阶地的形成与演化受新构造活动、山脉隆升、气候变化等多种因素的影响。

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.