Regional geological processes may be simulated rapidly using a combination of image processing and expert system techniques. Rapid, interactive simulations are achieved with image processing and a reduction of the problem to the two map dimensions. In order to manage these multiple simulations, expert system software is used to infer the optimum path through the modelling options. We illustrate our approach by referring to a computer system designed to produce maps of the prospectivity of carbonate-hosted Pb-Zn-F-Ba buried mineralization in the East Midlands of England. The system simulates the process of mineralization near the end of the Carboniferous involving the rapid expulsion of metal-rich brines from a series of small, shale basins by E-W compressive tectonism. There is preferential migration of these fluids along reactivated basin-bounding faults and deposition of the metals as sulphides within neighbouring limestone platforms. Computer simulation using this or similar approaches has particular potential for multidisciplinary projects in regional geology where disciplinary expertise in handling different types of data and in performing the simulation needs to be replicated.