四川小金抚边河断裂的晚第四纪活动特征  

LATE QUATERNARY ACTIVE CHARACTERISTICS OF FUBIANHE FAULT IN SICHUAN′S XIAOJIN

作　　者：周荣军[1] 何玉林[1] 马声浩[1] 黎小刚[1] 

机构地区：[1]四川省地震局工程地震研究所

出　　处：《地震研究》1999年第4期376-381,共6页Journal of Seismological Research

摘　　要：１９８９ 年９ 月２２ 日小金６－６ 级地震和本次地震的前震（１９８９ 年３ 月１ 日的５－０ 级）及余震（１９９１ 年２ 月１８ 日的５－０ 级） 均发生于小金两河口—木城附近， 这３ 次地震的震中连线及其等烈度线长轴皆大致呈Ｎ３０°Ｗ 方向， 暗示着该区存在北西向的活动构造。本文在航空照片判译和野外实地调查的基础上， 初步查明了抚边河断裂的空间展布特征。通过断错地貌的研究， 结合热释光（ＴＬ） 测龄结果， 首次发现了抚边河断裂晚第四纪以来以左旋走滑运动为主， 并兼具一定倾滑分量的地质证据， 其平均水平滑动速率在１－３ ±０－１ｍｍ／ａ 左右。最后讨论了抚边河断裂的可能地震能力。Xiaojin M6 6 earthquake on Sept. 22, 1989 and its foreshock(March 1, 1989 M5 0), aftershock(Feb. 18, 1991 M5 0)all occurred in the zone of Lianghekou Mucheng, Xiaojin County. The line contacting the three epicenters and their major axis of intensity isolines all distributed along the orientation of N30W approximately. This implies there is an active structure of NW direction in the area. On the basis of investigating the aerial photos and sites, this paper makes the spatial distribution features of Fubianhe fault clear. Through studying rapture topography and the result of TL method, the paper first proposes some geological evidences that Fubianhe fault is a left lateral fault with some dip slip component since late Quaternary, and the average slip-rate of the fault is about 1 3(0 1 mm/a. In the end of the paper, the capability of occurring earthquake of Fubianhe fault was discussed.

关 键 词：断错地貌 平均滑动速率 晚第四纪 四川 地震地质 

分 类 号：P315.7[天文地球—地震学] P542.3[天文地球—固体地球物理学]