鲜水河活动断裂带乾宁断层的构造地貌特征及全新世滑动速率

The Morphotectnic Features and the Quaternary Slip Rates Along the Qianning Segment of the Xianshuihe Fault Zone

一、引言乾宁断层位于鲜水河断裂带北西段的南东部.该断层北西起自松林口,向南东经龙登坝、四十道班、红光乡,终止于惠远寺盆地南东端的太吉图附近(图1).其北西端与道孚断层的接触关系不十分明确,南东端与雅拉河断层左阶距9.5km.

Geomorphic features along the Qianning fault reveal that two uplifts and two areas of subsidence have developed at the fault terminations,The seismic surfacial deformation for the 1893 M 7(1/4)earthquake has controlled strictly by the fault.Bared upon the study of tectonic landforms and historical surfacial rupture,the Qianning fault is a fault segment as a unit of independent rupture.The slip rate on the fault is 15mm/a since late Quaternary.The above data affest to the potential for an earthquake similar to the 1893 event for this fault.