帕米尔东北缘-西昆仑的构造地貌及其构造意义

Morphotectonic study from the northeastern margin of the Pamir to the West Kunlun range and its tectonic implications

帕米尔东北缘-西昆仑位于青藏高原西北部,受三条大型断裂:康西瓦断裂、主帕米尔-铁克里克断裂和公格尔断裂的制约。通过野外考察、卫星遥感图像解译、ASTERGDEM高程数据的分析,对上述三条断裂及整个区域进行构造地貌研究,并探讨其构造意义。结果表明:康西瓦断裂为左行走滑断裂;主帕米尔-铁克里克断裂为逆冲断裂;公格尔断裂和塔什库尔干断裂分别为右行、左行走滑正断层,连接两者的是塔合曼正断裂。通过ASTERGDEM高程数据的高程分布、局部高程差和坡度分析,表明帕米尔东北缘-西昆仑至塔里木盆地存在三级特征地貌(塔里木盆地、塔里木盆地南缘山前褶皱逆冲带和帕米尔东北缘-西昆仑);西昆仑地区受印度/亚洲板块碰撞而产生垂向物质运动,由于三条大型断裂控制在西侧断裂附近存在水平方向的物质运动,垂直和水平两种运动的存在促使靠近康西瓦和公格尔断裂形成高山地貌。

The region from the northeastern margin of the Pamir to the West Kunlun range is an important part of the northwestern Tibetan Plateau,which is surrounded by the Kongur normal fault,main Pamir thrust-Tiklik fault and Karakax fault in the northwest,northeast and southeast,respectively.According to detailed field survey,satellite images interpretation and ASTER GDEM data analysis,it shows that：（1） the Karakax fault is a left-lateral strike-slip fault;（2） the main Pamir thrust-Tiklik fault is a thrust fault;（3） the Muji fault segment of the Kongur normal fault and the Tashkorgan fault are the right-lateral and left-lateral strike-slip faults with a significant normal component,respectively,and lastly,the Tahman fault between the Kongur and Tashkorgan faults is a normal fault;（4） ASTER GDEM data analysis,including elevation distribution and local relief and slope measurements,shows that three main terrains exist within this area：the Tarim Basin,the mountain piedmont along southwestern margin of the Tarim Basin and the northeastern margin of the Pamir-the West Kunlun range;（5） the uplift and lateral extrusion are controlled by the Indian-Eurasian collision and boundary faults of the northeastern margin of the Pamir and West Kunlun,respectively.