摘要
地壳表层构造和深部构造互相制约是控制河北地区许多强震发生的必要地质条件。由此地质条件,在水平与垂直两个相互叠加的应力场作用下,使河北地区发生许多强震。这个构造-应力场模式,对华北地区许多强震的发生可能具有普遍意义。
Many strong earthquakes in Hebei region are controlled by NE-NNE and NW-NWW active faults and faultsubsidence basins of Cenozoic ear. All these faults, having obvious activity since Cenozoic era,are high-angle ordinary faults,and situated at the Bouguer gravity anomaly gradient zone. The deep tectonic characteristics of the strong earthquake areas are the uplift area of upper mantle,upon which there is lower velocity-higher conductive layer at the middle of the earth's crust, and deep great faults that cut off the Moho surface.The interactive of the earth's crust surface tectonic and the deep tectonic is the essential condition to control the occurrence of many strong earthquakes in Hebei region.They happened in the region resulted from the tectonic areas that were overlapped by horizontal and vertical stress fields.This tectonic-stress field model may has general sense to many seismogenic tectonics of strong earthquakes in North China region.
关键词
地震
强震
地质条件
构造模式
strong earthquakes, tectonic-stress field model, Hebei Province, seismogenic geology
