Western United States lithosphere-asthenosphere interaction: Modern day small scale convection, plume and ancient lithospheric heterogeneity

I present teleseismic imaging results from several temporary arrays in the southern and northern Rockies in the western U.S. This part continental lithosphere is a perfect lab in the world to study continent growth, stabilization and reactivation due to numerical mantle processes since the continental formation. A major hypothesis to test in this dissertation is the continent in the southern and northern Rockies retains its upper mantle structural heterogeneities formed during the early accretionary events, and remains as a kinematically stable lithosphere during subsequent tectonic events since the accretion. The main goals of this dissertation are to pursuit fine scale high resolution lithospheric seismic images of this region, focusing two primary key structures that record different stages of continent growth: the old Precambrian suture zones that mark the amalgamation of distinctly aged lithospheric provinces in 1.8--1.6 Ga, and the late Cenozoic Yellowstone hotspot track system that has been injecting magma into stable continental crust since 17 Ma. Methods such as body-wave tomography, receiver functions and a newly developed shear-wave splitting method are used in this thesis.