The use of a forward kinematic model in the construction of balanced cross sections

Abstract

Nowadays, cross section balancing is a popular technique. However, there is sometimes a lack of data at depth so that the problem is not clearly expressed in terms of the kinematics of deformation. In this paper a forward modeling program of thrusting is presented, which when used with a trial and error procedure allows the simulation of intermediate and final state geometries of a thrust belt. Together with the classic assumptions used in cross section balancing, severals rules for fault bend folding have been selected for use in this model. The forward modeling illustrates three important characteristics of balanced cross sections: (1) the critical importance of stratigraphic thickness and displacement at the trailing boundary, (2) the redundant character of angular surface data, (3) the generally unconstrained character of the problem. Advantages derived from using a forward modeling approach are: (1) to examine the validity of several different structural interpretations in which the input parameters may be varied, (2) to simulate both final and intermediate stages, and (3) to generate the large displacement of a mesh necessary for the application of physical models. In the last part of the paper, geological structures of the Appalachian Mountains, Jura, and Barbados accretionary prism are modeled.