The basic purpose of the research carried out under this grant was to obtain a better understanding of deformation processes in the western United States. The research considered both deterministic models and random or statistical models. One important aspect of deformation is the rheology of the lithosphere. We have been one of the leading proponents of an intracrustal asthenosphere. This is a soft zone at mid-crustal depths that has an important effect on a variety of tectonic phenomena.
United States, National Aeronautics and Space Administration, "Mechanisms of Crustal Deformation in the Western United States" (1986). Geology. Paper 2.