SEISMOGENIC STRUCTURE OF THE XINGTAI EARTHQUAKES

Recent seismic reflection profiling has confirmed the existence of the listrie and normal faulting in the:upper crust of the Xingtai area.Fault plane solutions of the Xingtai earthquakes and the relevant ground deformation observations show that the seismogenic struetrure may not be the normal faults indicated by geological maps.In this paper a new mechanical model is proposed for the Xingtaiearthquakes, these events were caused by the horizontal dislocations along the vertical weak zones in the crust under the action of the regional tectonic stress field.These weak zones areclosely related to the Cenzoie crustal extention and the vocanic rock intrusions of North China.