Emergent distributions of stress and strain in fault damage zones

Simulation models of faulting based on realistic poro-plastic geomaterials develop complex but wellordered strain patterns that are very similar to those observed in natural fault damage zones. The stress states in the simulations are complex, and exhibit substantial changes during the faulting process. The material properties of the materials in the FDZs are significantly altered as the deformation progresses. None of the current approaches to predicting fault stability or fault sealing is compatible with the conditions revealed by these simulations. There is a need to re-consider the basis for making such predictions to determine where the current methods might be approximately right, and where new methods are required.