Dynamic Analysis of Deformational Structures of the Xiannüshan Fault Zone in the Three Gorges of the Yangtze River

Field investigation and laboratory work reveal that inhomogeneity of the deformation of the Xiannüshan fault is mainly characterized by lateral zonation, longitudinal segmentation and downward stratification. Based on these results, a 3-D deformational structure model of the fault was established and its geometrical and kinematic characteristics in two main deformational stages i.e. the main Yanshanian and Himalayan were discussed. The directions of principal and the differential stresses in these two stages were determined by using conjugate joints, striations of fault planes and microstructures of the fault zone. The direction of (1 is N-S in direction with differential stresses of 150(250 MPa in the Yanshanian, and N70E with a differential stress ranging from 80-120 MPa in the Himalayan.

Dynamic Analysis of Deformational Structures of the Xiannüshan Fault Zone in the Three Gorges of the Yangtze River

Field investigation and laboratory work reveal thatinhomogeneity of the deformation of the Xiannüshan fault is mainly characterized bylateral zonation, longitudinal segmentation and downward stratification. Based on theseresults, a 3-D deformational structure model of the fault was established and itsgeometrical and kinematic characteristics in two main deformational stages i.e. the mainYanshanian and Himalayan were discussed. The directions of principal and the differentialstresses in these two stages were determined by using conjugate joints, striations offault planes and microstructures of the fault zone. The direction of (1 is N-S indirection with differential stresses of 150(250 MPa in the Yanshanian, and N70E with adifferential stress ranging from 80-120 MPa in the Himalayan.