Fracture

A fracture is a crack in rock due to an external force, regardless of whether any relative displacement has occurred. Fractures include fissures, joints and faults. The fracture surface, faulted rock, hanging wall, footwall, upthrow, downthrow, displacement (including slip and throw) and slickensides are the basic elements of fractures. Based on the direction of slip, faults can be categorised as strike-slip faults, dip-slip faults, oblique-slip faults and bedding faults. Based on the relative motion of the upper and lower blocks, faults can be catetegorised as normal faults, reverse faults (thrust faults) and transform faults (strike-slip faults). According to their depth, faults can be categorised from shallow to deep as superficial faults, basement faults, crustal faults and lithospheric faults. Based on their rock mechanical properties, faults can be categorised as brittle fractures (forming cataclastic tectonites), brittle-ductile fractures and ductile fractures (forming...