Abstract:

Excavation of trenches revealed three palaeoseismic events along the southern boundary fault of Xianhua basin. They occurred in 8.54 ka,7.08 ka,and 5. 31 ka B.P.,respectivly,The average reccurence interval is1 615±360a. The displacement of three events are 0.55～0.74m,0.52～0.7m and 1.63～2.2m,respectivly.However,the event displacing the surface has not occurred since 5.31 ka B.P.,suggesting that reccurrence interval of palaeoearthquakes is not simply quasi-periodic.

Key words: Paleoearthquake, Active fault, Xuanhua-Huai’an basin

摘要：

通过开挖,在宣化盆地南缘断裂上揭露出3次古地震事件,发生的年代分别距今约8.54、7.08和5.31ka,平均重复间隔1615±360a.事件位移量分别为0.55～0.74m、0.52～0.7m和1.63～2.2m.但距今5.31ka以来断裂未发生过断错地表的运动,意味着其古地震重复不是简单的准周期型。

关键词: 古地震, 活断层, 宜化-怀守盆地