五台山北麓断裂南峪口段晚第四纪活动与古地震  

Late Quaternary Activity and Paleoearthquakes along the Nanyukou Segment of the Northern Piedmont Fault of the Wutai Mountain

作　　者：丁锐[1] 任俊杰[1] 张世民[1] 

机构地区：[1]中国地震局地壳应力研究所,北京市德外西三旗100085

出　　处：《中国地震》2009年第1期41-53,共13页Earthquake Research in China

基　　金：中国地震局地壳应力研究所基本科研业务专项(ZDJ2008-07;ZDJ2007-14);地震科学联合基金(C07028);地震行业科研专项(200708028)共同资助

摘　　要：五台山北麓断裂位于山西断陷系的北部,是繁代断陷南界的控制断裂,其南峪口附近段落在晚第四纪表现出较强的活动性,在晚第四纪洪积扇上形成了高达20～30m的断层陡坎。近20ka以来,该断裂段的平均滑动速率不小于1.55～2.0mm/a,近6ka以来滑动速率达2.3mm/a,高出其它段落平均滑动速率近1倍。在南峪口段的2个探槽共揭露出6次可能的古地震事件,其参考年代距今分别为7600a以前、6700～7600a、5321～5575a、4400～5400a、4200～4400a和1600a以来,平均复发间隔约为1400a。其中最新活动事件可能是公元512年的地震。The northern piedmont fault of the Wutai Mountain locates at the north of the Shanxi Graben system, which is the dominate fault of the south boundary of the Fancheng-Daixian depression. This paper tries to discuss fault activity and paleoearthquakes around the Nanyukou segment of the northern piedmont fault of the Wutai Mountain during the late Quaternary by doing field investigation along the fault, measuring geomorphic deformation and excavating trenches in some important sites. From Nanyukou to the southwest of Shanhui, we can find alluvial fans were displaced obviously, the neotectonic movement at these sites is strong. Since nearly 20ka, the vertical average slip rate is 1.55mm/a to 2.0mm/a. However, since nearly 6ka, it reaches at as high as 2.3mm/a, which is twice higher than other segments. 2 trenches are excavated around Nanyukou and 6 events are discovered, referenced ages of events are before 7600a, 6700 - 7600a, 5321 - 5575a, 4400 - 5400a, 4200 4400a and after 1600a B.P. and recurrence interval is approximately 1400a. The latest event is likely to be the earthquake that occurred at 512 A.D. So it is necessary to do further work to conform in future.

关 键 词：五台山北麓断裂 晚第四纪 断层崖 古地震 滑动速率 

分 类 号：P315[天文地球—地震学]