Abstract - The relationship between the maximum cumulative
displacement on a fault (D) and the maximum linear dimension of
the fault surface (W) is given by the expression D = cWn
where the value of c is determined by rock properties; proposed
values for n range from 1.0 to 2.0. Published datasets of D
vs W measurements, together with new data, are presented in a common
format. Most datasets are derived from maps and so the measurements of
displacement and length do not represent maximum values for each fault.
This factor, together with greater than an order of magnitude range of
c, causes regression on D vs W plots to be unsafe
unless the range of W values plotted is ca 5 orders of magnitude.
This restriction means that individual datasets must be combined to achieve
the required range of fault size. Data analysis shows that the value of
n must exceed 1.0 but discrimination between values of 1.5 and 2.0
cannot be made on the basis of data analysis alone. A modified fault growth
model in which the increase in dimension of a fault with each slip event
is proportional to W0.5 gives rise to a value for n
of 1.5. As this model has a sound mechanical basis 1.5 is the preferred
value for n. The value of n influences other aspects of fault
geometry, including the displacement profile on a fault surface, the spacing
of depth contours on faulted horizons and the displacement populations
of single fault surfaces.
Journal of Structural Geology 14, 1157-1172, 1992.