Abstract: Thrust faults are widely developed in Yakela faulted salient due to long-term compression regime.However,some normal faults were also formed during the Early Himalayanian.In order to decode the mechanism of formation and evolution of these faults,we conducted 3D finite element numerical simulation for the Late Hercynian and Early Himala-yan stress field in the Yakela faulted salient.During the Late Hercynian,the compressive stress resulted in the low stress areas in the central and eastern parts of the Yakela faulted salient and the low to moderate stress in the west and north part.This stress field caused the development of some small-scale thrust faults in the Yakela faulted salient.During the Early Himalayan,the compressive stress induced uplifting of the study area,with the amplitude of uplifting increasing from west to east.As a result,the strata bended in the study area,with the strongest tensile stress occurring on top of the boundary fault,and normal faults were also developed in these locations and extended inwards.Meanwhile,compression stress was weak in the lower part of the whole study area,thus did not induce the further development of thrust faults in the inner parts of the study area.

Key words: Late Hercynian, Early Himalayan, numerical simulation, tectonic stress field, Yakela faulted salient, Tarim Basin