Role of fluids in faulting inferred from stress field signatures
The stress orientation signature of weak faults containing high-pressure fluids has been observed for segments of the San Andreas fault system in southern California. The inferred lithostatic fluid pressures extend into the surrounding relatively intact rock in a zone scaling with the width of the interseismic strain accumulation. Repeated strain-related fracturing and crack sealing may have created low-permeability barriers that seal fluids into the network of currently active fractures.
Seismological Laboratory, MC 252-21, California Institute of Technology, Pasadena, CA 91125, USA.
JL
Hardebeck
E
Hauksson