Large volume strain has been reported from several studies involving deformed thrust wedge packages, but little is known about the mechanism of mass transport. This project will use stable isotope geochemistry and whole-rock composition data to assess the role of fluid flow and to determine the direction and quantity of flow. Results should further quantify volume strain in the late Cretaceous San Juan-Cascade nappes of western Washington and provide insight into the direction and magnitude of fluid flow responsible.
