西藏喀喇昆仑断裂东南段晚第四纪活动的地质地貌特征

Geological and Topographical Features of Karakorum Fault in Southeastern Segment,Western Tibet Plateau at Late Quaternary

为了分析西藏喀喇昆仑断裂东段段第四纪活动地质地貌特征,通过对该段进行遥感影像、野外地质地貌调查、断错地貌测量等方法和手段,获得了该断裂晚第四纪活动的地质地貌特征。在扎西岗北东河流阶地中发现断裂切割全新世的阶地堆积物。同时,对断裂不同的地段进行断错测量,获得了定量的断层数据,反映了断层活动的幅度及期次。研究结果表明,该断裂东南段晚第四纪以来右旋走滑量介于2～220 m,具有多期次活动特征,活动方式以右旋走滑为主,兼具正断分量。

In order to investigate geology and geomorphology feature of the western Karakorum fault segment,several methods were used to the geomorphic activity of the fault,including remote sensing image,geology,geomorphology survey and offsets of microrelief measuring.The active features on geology and geomorphology of the fault since the Late Quaternary Period were obtained.It was found that the Holocene terrace sediments are offset in northeastern Zhaxigang.Meanwhile,several methods were used to measure the offset values and this reflected the faulting and dimension and time.The preliminary study indicates that the microrelief is offset,ranging from 2~220 m in Late Quaternary.The fault was characterized by multi-time activity and dextral strike slipping,with normal fault offset.