Figure 13. A generalized left-lateral Riedel shear model (rotated to have the same orientation as Saybrook), in two stages of development: a) initially with only synthetic Riedels (R) and b) later with antithetic (R') (adapted from Mandl, 1988 and Ahlgren, 2001). The regularly spaced extension along sub-seismic antithetic faults combined with minor dip-slip movement may have helped to develop fluid migration pathways.