Pressure solution lithification as a mechanism for the stick‐slip behavior of faults

Many major faults, including a large fraction of the San Andreas, appear to be virtually quiescent between great earthquakes. The locked sections of the San Andreas near San Francisco and Los Angeles have little or no seismic activity on the primary fault trace, although secondary faults may be active. Stick‐slip behavior on a fault can be explained in terms of a static coefficient of friction, which is larger than the dynamic or sliding coefficient. In this paper we propose a modification of the friction hypothesis in which chemical lithification (cementation) occurs on the fault between earthquakes. As the stress on the fault increases it becomes large enough to break the cemented bonds between particles causing slip on the fault. We treat this problem quantitatively, assuming that pressure solution is responsible for the cementation. An advantage of this model is that the hydrostatic pressure approaches the lithostatic pressure during cementation so that low fault strengths are predicted.