摘要
安宁河断裂带是中国西南地区一条重要的地震活动断层,地方志记载公元1536年曾发生过震级大于7级的破坏性地震.详细的断裂地貌航片解译和野外调查表明,安宁河断裂带除具有主要的左旋走滑断层活动外,还兼有重要的逆冲运动分量.根据冲沟和阶地面的位错量及其热释光测年结果估计,该断裂带晚更新世以来平均左旋走滑速率为3～7mm/a.根据滑移方向与断层走向的关系,推测跨安宁河断裂带东西向由于逆冲断层运动造成的挤压缩短速率约为1.7～4.0mm/a;简单分解鲜水河断裂带上的滑动速率,估计分配在大凉山断裂带上的滑动速率与安宁河断裂带上的大致相当,约为3～7mm/a.此外,根据野外调查结果,并结合最近青藏高原构造动力学研究的新认识,建立了安宁河断裂带的动力学模型,认为安宁河断裂带是一条逆冲走滑断裂带.其下盘(西盘)主动向南东方向下插,造成了上盘(东盘)向北西方向的上冲运动.
The Anninghe fault is one of the Southwest China. Local historical curred in the year of 1536. On the basi the significant record shows earthquake-g that a M≥ 7 enerating fault zone strong earthquake s of the detailed air-photographic interpretation s in oc- and field investigation, we have acquired the following knowledge： ① The average sinistral strike-slip rate since the Late Pleistocene is about 3-7 mm/a; ② There is important reverse faulting along the fault zone besides the main left-lateral strike-slip motion, and the shortening rate across the Anninghe fault zone due to the reverse faulting is about 1.7 4.0 mm/a. If the Xianshuihe fault zone is simply partitioned into the Anninghe and Daliangshan faults, we can also get a slip rate of 3-7 mm/a along the Daliangshan fault zone, which is the same as that on the Anninghe fault zone. Moreover, on the basis of our field investigation and the latest knowledge concerning the active tectonics of Tibetan crust, we create a dynamic model for the Anninghe fault zone.
出处
《地震学报》
CSCD
北大核心
2007年第5期537-548,共12页
Acta Seismologica Sinica
基金
地震科学联合基金(105066)
国家自然科学基金(40472109)
日本科学协会笹川科学助成金共同资助.
