The geometry of listric normal faults and deformation in their hangingwalls

In cross-sections containing listric extensional faults, area balancing techniques for depth to décollement are usually based on either bed length conservation or displacement conservation. Listric fault geometry may be constructed from a hangingwall roll-over profile using the ‘Chevron construction’. This construction, based on conservation of heave, necessitates a reduction in fault displacement with decreasing fault dip. A modification of this construction utilizing conservation of fault displacement predicts a listric fault that detaches at a shallower depth. A new construction based on slip lines uses fault-perpendicular displacement segments to generate listric fault shape. Fault propagation strain may be responsible for anomalous hangingwall geometries, and these can be predicted by forward modelling using either a modified Chevron construction or a slip-line construction.