LOCACE: Computer-aided construction of balanced geological cross sections

LOCACE is a workstation-based interactive system designed to test the geometrical coherence of geological cross sections. The approach is to restore the geological layers in their predeformational state with the help of simple balancing principles. This methodology is suitable for extensive and compressive terrains as well. While a successful restoration does not guarantee a correct final interpretation, it checks the geometrical soundness of the geologist's hypotheses. The section is restored step by step following a logical sequence determined by the direction of the tectonic transport. Several methods of restoration were developed for layers with constant of varying thickness. Synsedimentary faults and rotation of rigid blocks also are taken into account. The deformation methods can be applied backward or forward in time. The entire testing process is facilitated by powerful graphical editing functions that allow the user to modify the geometry of the depth-corrected seismic interpretation and of the restored cross section. LOCACE has been developed jointly by the French Institute of Petroleum, the Societe Nationale Elf Aquitaine (Production), Total-Compagnie Francaise des Petroles and AGIP. The program is written in C language and runs under Unix.