Abstract: Based on the recent data from petroleum geological prospecting and the reexplana-tion of the relevant segment of deep seismic sounding profile from Yuanshi county, He-bei Province to Jinan, Shandong Province, the tectonic background and causative fault of Xingdai MS7.2 earthquake have been analysed in this paper. The results have shown that the epicentre of MS7.2 earthquake was located at the eastern margin of southern sub-depression within Shulu fault basin. The sub-depression developed in a fault block which was formed from the cover of platform cut and bound by four listric faults. There are two high angle faults beneath the fault block. By contrast with previous opinion, the authors propose that there is no simple corelation between seismicity, major fault and fault-controlled depression. The causative fault of MS7.2 earthquake was neither the gentle-dipping Xinghe listric fault, nor the high angle F3 fault, and the deep-seated eastern fault, but was the combination of the three faults. The high angle fault was the main part of the causative fault.

Key words: Xingdai, Shulu fault basin, Xinghe -fault, Causative fault of Xingdai Ms7.2 earthquake

摘要： 本文根据石油地质勘探的最新资料和元-济人工地震地壳测深剖面相应地段重新解释的结果,分析了邢台7.2级地震的构造背景和发震断裂。研究结果表明,7.2级地震震中位于束鹿断陷盆地南部次凹的东缘,该次凹发育在由新河断裂等4条缓倾铲形正断裂分制围限地台盖层而成的“斛”状构造块体上,块体之下的地壳中存在两条倾向相反的高角度断裂;地震与断陷主断裂及其控制的断陷盆地并非是简单的对应关系,7.2级地震的发震断裂不是单一的缓倾铲形新河断裂或其下方的高角度的F₃断裂和深部的东断裂,而是它们的组合,且高角度断裂是发震断裂的主要部分。

关键词: 邢台, 束鹿断陷盆地, 新河断裂, 发震构造