Dating Thrust-Fault Activity by Use of Foreland-Basin Strata

Abstract

Foreland basins form at the sides of thrusted mountain belts because of flexure of the lithosphere under a load. In retroarc and in some peripheral foreland basins, the entire flexure results from the load of thrust sheets. Thus the subsidence history of the basin is an indirect measure of the history of thrusting. Although the texture and migrations of facies of the basin fill certainly respond to thrust motions, they also depend on the other independent controls (climate, the lithology of the thrust belt, and base level). Therefore it is unreliable to use textural history or facies migrations as indicators of thrust history.