SIMULATIONS ON THE FORMATION AND EVOLUTION OF CONTEMPORANEOUS FAULTS IN THE LOWER YANGTZE AREA

In this paper,nonlinear theory and plastic flowing theory are applied to the study of contemporaneous faults, and the analysis program for the simulation of the formation and evolution of the contemporaneous faults have been written by using FORTRAN 77 Language with two-dimention elastic-plastic nonlinear (equal-parameter, eight-node elements). The study suggests that the growth of contemporaneous faults originated from the stress of the hanging walls. Combining with the geological and geophysical data of the study area, it is also proposed that the formation of the Tai Lake Dome Structure was brought about by the upward-stress due to the soft layers' thickenings resulted from plastic flowing at the bottom of sedimentary cover under the action of horizontal stress-field. In addition, it is suggested that the formation of grabens and horsts would be related to the faults developed in early stage and their boundary conditions, and is the result of their assembled efffects.