What Plate Is Subducting Under The North American Plate?

What Plate Is Subducting Under The North American Plate? Figure 19.1. Landscape map that shows the US part of the Juan de Fuca plate. The Juan de Fuca and Gorda ridges mark the divergent plate boundary (the spreading ridge) with the Pacific plate. The Cascadia trench marks the subduction zone with the North American plate.