东昆仑山东段北坡河流阶地发育及其与构造隆升的关系  

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

作　　者：王岸[1] 王国灿[1] 向树元[1] 

机构地区：[1]中国地质大学地球科学学院,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2003年第6期675-679,共5页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目(No.40072062);中国地调局1:25万阿拉克湖幅区域地质调查项目(No.19991300004021);中国地调局1:25万库赛湖幅;不冻泉幅区域地质调查项目(No.200313000005);国家地质学理科基地基金

摘　　要：河流系统的发育往往能反映相关地质作用的细节.对东昆仑山东段北坡众多河流阶地及其沉积物的研究表明,该区在早更新世晚期昆仑-黄河运动之后形成的东西向盆岭相间的地貌特征奠定了早期河流为东西向外流水系的基础;中更新世晚期以来的又一次强烈构造抬升事件———共和运动,导致昆仑山北坡各主要河流迅速溯源侵蚀发展,伴随河流袭夺而形成现今的水系格局;晚更新世晚期存在一段相对较长的构造稳定期,河谷普遍发生堆积作用,形成分布广泛且厚度较大的晚更新世冲积层;接近全新世以来构造运动频繁而隆升的幅度趋于减弱,形成了5级河流阶地,并且阶地的发育类型普遍为以高级阶地(T5)为基座的上叠阶地,河流至今未能切穿晚更新世稳定期形成的厚冲积层.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.

关 键 词：河流阶地 构造隆升 东昆仑山东段 

分 类 号：P548[天文地球—构造地质学]