晚新生代青藏高原北缘构造变形和剥蚀变化及其与山脉隆升关系  

TECTONIC DEFORMATION,DENUDATION VARIATION AND MOUNTAIN UPLIFT AT THE NORTH EDGE OF THE TIBETAN PLATEAU DURING THE CENOZOIC

作　　者：马钦忠[1] 李吉均[2] 

机构地区：[1]上海市地震局,上海200062 [2]兰州大学地理科学系,兰州730000

出　　处：《海洋地质与第四纪地质》2003年第1期27-34,共8页Marine Geology & Quaternary Geology

基　　金：国家重点基础研究发展规化青藏项目(G1998040802)

摘　　要：青藏高原的差异性隆升是一个涉及高原隆升过程和机理的重要科学问题。利用青藏高原北部塔里木盆地、柴达木盆地与河西走廊盆地的地层沉积序列推算了高原北缘西昆仑山、阿尔金山和祁连山系晚新生代以来的山脉剥蚀幅度变化特征,得到了青藏高原北缘山系隆升运动差异的传播比,它们基本上反映了晚新生代西昆仑山、阿尔金山和祁连山隆升运动的差异程度。高原北缘山系垂直运动速率的计算值与实测资料对比是相吻合的。进而研究了青藏高原北缘山系构造缩短变形、剥蚀变化与山脉隆升的关系。研究表明,青藏高原二期隆升时祁连山的高度在2400～3100m的范围内。The uplift difference of the Tibetan Plateau is very important to deal with the process of its uplift and formation mechanism. Based on the analysis and the mass budget of the sediments deposited in the Tarim,Qaidam and Hexi Corridor basins of the north Tibetan Plateau, we study the varying patterns of the denudations of the west Kunlun Mountain, Altin Mountain and Qilian Mountain since late Cenozoic. We get the propagation ratios of uplift differences among these mountains, which basically reflect the discrepancies of the mountains' uplift. It is shown that the agreement between the calculated values and the data from field measurements of the mountains' uplift rates is very good. Further more, we study the relationship among the tectonic deformation, denudation variation and mountains' uplift at the north edge of the Tibetan Plateau. There is a linear relationship among the mountain altitudes, denuded thicknesses of the mountains, and strain of the tectonic shorting by the squeezing action in the north mountain system of the Tibetan Plateau. Since the Miocene there have been more differences in the average rates of denudation and in the changes of denuded thicknesses along the mountain system of the West Kunlun, Altin and Qilian at the north margin of the Tibetan Plateau. These differences are caused by the tectonic differential movement and climate changes in the eastwest direction, but the latter play a less important role in it. The study shows that the altitude of the Qilian Mountain was 2 400～3 100 m during the second uplift of the Tibetan Plateau.

关 键 词：晚新生代 青藏高原 剥蚀变化 构造变形 山脉隆升 传播比 垂直运动速率 地层沉积序列 

分 类 号：P542[天文地球—构造地质学]