Gravitational collapse driven by the excessive potential energy of the lithosphere owing to over thickened crust or deep thermal perturbations is believed to be the primary mechanism for Tertiary extension in the North American Cordillera. The objective of this project is to constrain the major parameters controlling gravitational collapse and their possible implications for tertiary tectonics in the Cordillera. The research will combine geological and geophysical evidence from the Cordillera with physical modeling. The major processes to be investigated, such as rheologic stratification, localized strain softening and mechanical decoupling between rheological layers, are critical to the evolution of all continents. Insight gained from this research should have broad implications for continental tectonics.
