Abstract: Fault gouge is one of the main influence factors to the fault sealing. Dynamics and kinematics analyses are conducted on the mechanism of normal fault formation. From the time domain and space domain, the stress distribution of upthrow and downthrow blocks and the fault gouge distribution of normal fault are discussed. The study shows that the fault gauge is controlled by the fault and associated with the fault. The upthrow block is an active block and the downthrow block is a passive block. With the growth of normal fault, the fault gouge in the normal fault occurs in forms of thinning, elongate, smear and dragging as dynamic evolution process, and shapes to a certain width of the upthrow block of the normal fault.

Key words: normal fault, mechanics analysis, fault gouge, tectonophysics modeling