Summary

Fault growth in layered sedimentary rock may be understood by analyzing fault displacement profiles with respect to lithologic data. Fault data obtained from an interbedded sequence of clastic sedimentary rocks were used to construct such fault displacement profiles. Whereas profiles constructed from faults in homogeneous media often display continuous displacement gradients, our profiles exhibit many aberrant trends, such as increased gradients and noncentered, multiple maxima. We attribute these anomalies to the theory of fracture partitioning, which states that faults are initially confined to individual beds, and therefore display characteristics associated with fault growth in relatively homogeneous media. However, once isolated faults link across bed boundaries, the medium is no longer homogeneous, and the irregular profiles reflect this change from homogeneous to heterogeneous media. We conclude that universal models of fault growth used to predict certain fault characteristics, such as the location of maximum displacement and a continuous displacement gradient may not be applied to faults in layered sedimentary rocks.

AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah