Pacific northwest tectonic setting

Subduction in Cascadia has been underway for about 35 million years. It has produced a crustal architecture known from subduction zones around the world: an accretionary prism, extending from the deformation front into the continental shelf; a fore-arc region; a volcanic arc; and a back-arc region. These features are developed within a pre-existing continental framework, are modified by motion along the continental margin, and are overprinted by other plate boundary regimes as the extent of the subduction zone changes through time.