THE STRUCTURAL CHARACTERS OF THE PIEDMONT FAULT ZONE OF TAIHANG MOUNTAIN
Xu Jie Gao Zhanwu Song Changqing Sun Jianbao (Institute of Geology, China Seismological Bureau, Beijing 100029)
We have made a study to the piedmont fault zone of Taihang Mountain based on geological and geophysical data of recent years. Our new insights suggest that this fault zone began to emerge in Mesozoic and formed mainly in Early Tertiary. It consists of a series of NE NNE strike faults, which were arranged obligue in a left lateral manner. Its structures and activities have evident segmentation. Along the middle and north segment, the faults, such as the Baoding Shijiazhuang fualt, are of large detachment faults. They stretch about 70km horizontally in the tilt direction with horizontal offsets of 17km and vertical offset of 5000 6000m during Early Tertiary. This fault zone belongs to the detachment structure in the upper crust rather than a deep fault. It has weak activities since Quaternary and has no direct cause relation with major earthquakes. It is, however, still somewhat of importance to studies of regional seismotectonics and earthquake prediction, because both the south and north section of this fault zone intersect with other seismic zones which have different strikes.