Inverse modeling for possible rather than unique solutions

Abstract

Despite the implementation of several kinematic and mechanical models for fault-related folding, and the incorporation of structural uncertainty in geological models, structural modeling is still too deterministic. The current focus is on forward modeling of a unique fit. We show the application of trishear inverse modeling, global optimization and Markov chain Monte Carlo (MCMC) methods, to a clay model of basement-involved compressional faulting, from which we know both total and incremental deformation. Global optimization and MCMC methods provide a range of possible models rather than a unique fit.Total inversions give an average of the model's deformation, while incremental inversions are more physically related to the model's evolution. Global optimization identifies the full range of possible models, while MCMC characterizes expected parameter values and their uncertainties. Structural inversions without sound geology are meaningless. A robust stratigraphy, geomorphic markers, mesoscopic structures, analogue and mechanical modeling can all greatly improve the inversions.