Fracturing and Porosity Channeling in Fluid Overpressure Zones in the Shallow Earth’s Crust

Figure 7

Fracture evolution (in black, with fluid pressure color coded in the backgrounds) of two faulted layers with different Young’s moduli. (a) Soft layer with Young’s modulus of 10 GPa and (b) hard layer with Young’s modulus of 100 GPa. Both hard and soft layers show a similar fracture evolution with the first fractures developing at the end of the layers next to the fault followed by a brecciation of the layer itself. The fracture density is slightly higher in the hard layer with the main difference being the timing of fracturing, which is significantly earlier in the soft layer.