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安宁河断裂作为川滇活动地块东边界的主要活动断裂,研究其晚第四纪地表变形和强震破裂行为是认识断裂带乃至川西地区未来地震危险性的重要基础工作.通过详细地质地貌调查、数字影像分析、全站仪实测、组合探槽开挖和年代测定,对安宁河断裂冕宁以北段几个晚第四纪变形遗迹保存较好的地段进行断错地层地貌序列的研究,获得了一些新认识:紫马跨和野鸡洞两地点都反映出距今约1634~1811,1030~1050和280~550a左旋位移量在3m左右的强震事件,重复间隔为520~660a;大海子-干海子最年轻的事件应该是公元1536年的地震,其他事件别发生在距今1768~1826,2755~4108和4108~6593a.复发间隔为约1300~1900a.强震活动存在群集现象.安宁河断裂北段未来一段时间内有发生强震的可能性.
Anninghe fault, as the main active fault in the east boundary of Sichuan-Yunnan active massif, studying the Late Quaternary surface deformation and strong earthquakes is an important basic work to recognize the future earthquake risk in the fault zone and even in western Sichuan. Through the detailed geological survey , Digital image analysis, total station measurement, combined trench excavation and dating, a series of fault sequence stratigraphic sequences were studied on several well preserved Quaternary tectonic relics in the northern section of Mianning, Anninghe fault. Some new understandings were obtained: the strong mainshock events of about 3m left-handed displacements from about 1634 to 1811, 1030 to 1050 and 280 to 550a dating back to the present are reflected in both the purple horse cross and the pheasant cave hole, with a repeat interval of 520-660 a; The youngest member of Qianzi - Qianhaizi should be the 1536 Earthquake, and the other events do not occur in the range of 1768 ~ 1826, 2755 ~ 4108 and 4108 ~ 6593a, and the recurrence interval is about 1300 ~ 1900a. There is a cluster phenomenon of strong earthquakes. Anning River fault in the northern section of the next period of time there is the possibility of strong earthquakes occurred.