Modeling the effect of thrusting style on the evolution of foreland basin stratigraphy

The purpose of this study is to quantitatively model the interaction of geological processes relating to tectonics and sediment supply in order to analyze the resulting stratigraphic stacking patterns. While the relative influence of these factors are commonly debated in light of empirical studies, quantitative analyses of their interactions are rare.; For this study, a forward numerical model was constructed to simulate the interaction of geological processes specific to the foreland basin environment, including thrusting and orogenic uplift, lithospheric flexure, orogenic denudation, fluvial sediment transport and deposition in non-marine and nearshore environments. Input parameters are based on field studies and modern analogs.; Forward modeling of the development and evolution of the Western Cretaceous Interior foreland basin shows that numerical routines can be used to quantitatively simulate the interaction of geologic processes at a wide variety of scales. Model output encompasses scales from regional basin configuration down to local sedimentary stacking patterns. In using a forward modeling progression, non-unique scenarios are generated that can indicate specifically how geologic parameters and processes interact.; In this study, the forward numerical model is used to show that thrusting order can be discriminated on the basis of foreland basin geometry and sedimentary stacking patterns. Both large- and small-scale stacking patterns are indicative of the position and order of movement of imbricate thrust sheets. Changes between foreland-stepping (in-sequence) and hinterland-stepping (out-of-sequence) scenarios produce distinct changes in the architecture of the foreland basin fill.; Modeling results show that the Campanian section of eastern Utah and western Colorado likely reflects a prolonged period of out-of-sequence thrusting. Both third-order (106 years) and fourth-order (105 years) stacking patterns can be attributed to changes in the magnitude and rate of thrusting, independent of eustatic sea level changes.; Dissemination of research results is accomplished through peer-reviewed publications and public presentations. To underline the importance of conveying the results of innovative research, efforts have been made to communicate the importance of the themes and results to a wide variety of audiences, including geoscience professionals, the academic community and other public audiences.