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????????-????????жι????ò???????????????????飬???????????????????????????????????????о????????????????棬?????????-????????жι?????λ????????????????????-???????ж???????????????и??????Ъ??????????????м???????,??????????????,??????????????????????ж??????????λ???2~3 km???????????????????????????????γ?????????棻?????????????????NE-NEE???????????????????????????????????????

STUDY OF QUATERNARY ACTIVITY AND TECTONIC DEFORMATION MECHNISM OF MACHENG-TUANFENG FAULT BELT

On the basis of geological survey of tectonic landform and drainage as well as fault feature to the middle segment of Macheng-Tuanfeng fault belt,this paper involves its quaternary activity characteristic in seismology and geology and discusses on the tectonic deformation mechanism of the fault,combining the depth of earthquake source in study area.The preliminary analysis can be drawn from this study.The fault,which is characterized by normal faulting and right-lateral offset,is predominantly active in the middle Pleistocene and is weakening in the Late Pleistocene.The drainage offset is up to 2-3 km in the way of dextral motion.The host fault controls the branch fault and they share a sliping plane in the crust.The differential uplifting of crust and mantle depth,as well as regionally tectonic principal pressure stress field of NE-NEE orientation provide the fault motion with dynamic force source.