关于高桥断裂及其活动性的讨论

A DISCUSSION ON GAOQIAO FAULT AND ITS ACTIVITY

活动断层是工程厂址评价合格性的一个核心因素，高桥断裂就是三峡工程值得注意的一条重要断裂带。它的展布是以多段雁列排布为其特征的，显示了水平扭动兼有逆冲的运动特点。其新活动性有５点证据：１．１９７９年５月２２月龙会观地震（Ｍｓ＝５．１）与该断裂有关；２．沿断裂带滑坡分布密集成带，是区内平均面密度的１１倍；３．穿过断裂的河流反常系数（Ｋ）出现突变；４．跨断层的气汞测量显示异常；５．新年代学（ＳＥＭ）测定，断层最新一次活动时间是晚更新世（Ｑ３）。

The active fault is a core factor for evaluating the qualification of engineering sites,Gaoqiao fault is right an important fault zone which is being worth paying attention to for the Three Gorges Project.its distribution is characterized by multi- segment en echelon distribution,showing characteristics of horizontal twisting motion and thrust motion.its new activity has 5 evidences:1.The Longhuiguan earthquake(Ms=5. 1) on May 22,1979, is related with the fault;2.the landslides along the fault zone are dense to be in belt,being 11 times larger than the average surface density in the area; 3.the abnormal coefficient(K)of the river crossing the fault shows a sudden variation4.The gas-mercury measurements crossing the fault show anomalies; 5. By the neochuonologic(SEM)determination,the latest activity of the fault was in Upper Pleistocene (Q3).