Cyclical processes in the North American Cordilleran orogenic system

To understand linkages among processes that combined to build the North American Cordillera, we synthesize its tectonomagmatic history from the California accretionary wedge to the retroarc foreland of Wyoming. At this latitude, the Cordilleran magmatic arc experienced high-flux events (HFEs) at ca. 160-150 Ma and ca. 105-90 Ma. Retroarc shortening provided the main source of HFE magmas, which in turn created eclogitic arc roots that later foundered into the mantle and cleared the sub-arc region of excess mass, and provided space to accommodate renewed retroarc shortening. The forearc, arc, and retroarc regions all responded variably to this cycle of tectono-magmatic processes, and Laramide flat-slab subduction may have both disrupted and been enhanced by events within this cycle.