Shear-wave velocity structure in the northern basin and rangeAmmon

Abstract A new method based on the joint inversion of receiver functions and surface-wave phase velocities results in well-determined shear-velocity structures that are consistent with the compressional-wave structure, gravity, heat flow, and elevation data in the northern Basin and Range. This new inversion method takes advantage of average-velocity nformation present in the surface-wave method and differential velocity information contained in the receiver function method, thus min-imizing the nonuniqueness problem that results from the velocity-depth rade-off. An unusually thick (38 kin) and relatively faster crust and upper mantle are found in central and eastern Nevada compared to the thin (28 to 34 km) and slower crust and upper mantle of the western Basin and Range. We interpret the regions of thicker and faster crust and upper mantle as zones that have undergone l ss Cenozoic ex-tension relative to the surrounding regions to the west and north. The thick crust and consequently greater depth to the dense mantle material is consistent with the gravity low pattern in central and eastern Nevada. Simple gravity modeling shows both local and regional isostatic ompensation ccur within 40 km of the surface, indicating