Abstract: The traces of two paleo-seismological events,preserved in late Pleistocene sediments at a depth of 2m,were excaved by trenching technique at several sites along the surface fissure zone which was formed during 1976 Tangshan strong earthquake.The geological observation around the suberb of Tangshan city also found some similar evidences.By comparing and analysing surface fissure,seismic faults and liquification scale,seismic intensity for that event was estimated to more or less equal that for Tangshan quake.Based on the 14C dating and computation of sedimentory rate,two events may be estimated to have occurred 7665?105 years and 14865 years ago,respectively,suggesting a recurrence interval of about 7500 years for strong earthquakes in the study region.

摘要： 在1976年唐山地震形成的地面裂缝带上三个地段(市十中、市畜产公司牛马库和礼尚庄东)开挖了三个探槽,揭示出保存在晚更新世沉积物中的两次古地震遗迹。在唐山外围的地震地质调查中,也相应地发现了一次古地震形迹。文中通过对地裂缝和液化规模的类比分析,推测其烈度与1976年7.8级地震相近。古地震发生年代,经年¹⁴C年代测定和沉积速率估算,分别发生于距今7665±105年和14865年。大震重复间隔近似值为7500年。