Numerical modeling of foreland basin formation: A program relating thrusting, flexure, sediment geometry and lithosphere rheology

An algorithm has been developed which allows the flexural deflection of the lithosphere to be calculated under thrust loading and the geometry of the sedimentary infill in the adjacent foreland basin. To that purpose we have considered arbitrarily shaped thrust-load systems moving towards the foreland, and surface processes denudating the orogen and filling the basin. The regional compensation of topographic loads is based on the assumption that the lithosphere behaves as a thin prate with either homogeneous (elastic, viscoelastic) behavior or more realistic depth-dependent elastic-plastic rheology. When using heterogeneous rheology, the program calculates the flexural behavior as a function of crustal geometry and thermal regime of the lithosphere, thus relating the basin infill geometry with the deep lithosphere properties. We show some examples where the geometry of the basin and sedimentary infill (e.g. onlap/toplap patterns) are generated assuming different lithosphere rheologies and synthetic tectonic contexts which support the applicability of the model to study the formation and evolution of foreland basins. (C) 1998 Elsevier Science Ltd. All rights reserved.