芦山地震灾区宝兴县地震活断层探测成果介绍

Introduction on the Rresult of the Active Fault Detection of the Baoxing County Which is the Seismic Stricken Area of The Lushan Earthquake

2013年芦山7.0级地震发生后,宝兴县作为地震灾区,在灾后重建工作中划设了穆坪镇和五龙乡两个规划区。由于两个规划区均位于龙门山断裂带南段中央断裂附近,中央断裂的晚第四纪活动特征研究可以为宝兴县的的灾后重建工作提供科学依据。通过野外地质调查、地球物理探测及钻探等手段,对中央断裂的两个分支断裂即盐井断裂和五龙断裂的地质地貌及活动特征进行了揭示。研究结果显示五龙断裂线性特征较为清晰,为晚第四纪活动断裂,穿过五龙乡规划区,考虑到未来发生地震造成的地表断错问题,应进行地震活断层避让。盐井断裂线性特征较弱,断层规模较小,为早-中更新世活动断裂,可以不考虑其对穆坪镇规划区的影响。

After the 2013 Lushan MS7.0 earthquake in Baoxing County,as an earthquake stricken area,designated two planning areas for Muping and Wulong town in post disaster reconstruction.Since the two planning areas are located near the central fault of the southern section of the Longmenshan fault zone,the study of the late Quaternary activity characteristics of the central fault can provide a scientific basis for the post disaster reconstruction work in Baoxing county.By means of field geological survey,geophysical exploration and drilling,this paper reveals the geological feature and activity characteristic of Wulong and Yanjing fault fault,which are two branch faults of the central fault.The results show that the Wulong fault is a late Quaternary active fault and cross over the Wulong town planning area,and it’s linear characteristics are relatively clear.Considering the ground surface dislocated by the earthquake in the future,the seismic fault avoidance should be taken into account.The fault characteristics of Yanjing fault are weak,and the fault scale is small.As an earlymiddle Pleistocene active fault,it can be ignored its influence on the planning area of Muping town.