Since the North American west coast has a convoluted structure, significant work has been required to resolve the complexity.
[3][5][6][7] This phenomenon is one that accounts for the far-inland orogenisis of the Rocky Mountains and other ranges in North America which are much farther from the convergent plate boundary than is typical of a subduction-generated orogeny.
There is a concentration of velocity anomalies in the tomography that is thicker than the slab itself should be, indicating that folding and deformation occurred beneath the surface during subduction.
[2][10] Under this model, the North American continent overrode a series of subduction trenches, and several microcontinents (similar to those in the modern-day Indonesian Archipelago) were added to it.
These microcontinents must have had adjacent oceanic plates that are not represented in previous models of Farallon subduction, so this interpretation brings forth a different perspective on the history of collision.
[11] Other models have been proposed for the Farallon's influence on the Laramide orogeny, including the dewatering of the slab which led to intense uplift and magmatism.