Damage zones around strike-slip fault systems and strike-slip fault evolution, Crackington Haven, southwest England

A well exposed outcrop of Upper Carboniferous greywackes and slates at Crackington Haven, north Cornwall, shows several episodes of strike-slip faulting. Exposure-scale structures display many features typical of strike-slip fault systems including: splay faults, wing cracks, jogs, fault bends, fault branches, λ faults, rotated blocks, together with layer-parallel slip, and deformation of the wall-rocks. The strike-slip faults developed with a remote NNE-SSW trending maximum compressive principal stress (σ1). Interactions between anisotropic layering and faults with different orientations are important factors in controlling slip. Displacement (d)-distance (x) analysis indicates that variations in displacement gradient and the material anisotropy of the wall-rocks control the development and nature of damage structures. The strike-slip fault system shows an evolving pattern from isolated faults through segmented faults to interacting faults, an analysis of which is supported by the maximum displacement (dmax)-length (L) relationships for the fault population.