the sevier orogeny was the result of convergent boundary tectonic activity between approximately 140 million years (ma) ago and 50 ma. the sevier river area of central utah is the namesake of this event. this orogeny was produced by the subduction of the oceanic farallon plate underneath the continental north american plate. crustal thickening that led to mountain building was caused by a combination of compressive forces and conductive heating initiated by subduction in the sevier region which caused folding and thrusting.