Global subduction, rifting and movement of plates
has continued through all Earth history and continues today.
Off the coast of the Pacific Northwest , a spreading ridge (red)
separates the Pacific Plate moving to the northwest from the
Farallon Plate , moving to the southeast. The once immense Farallon
Plate is now almost completely subducted beneath Oregon. Three
trailing remnants remain—the Gorda, Juan de Fuca, and Explorer
microplates. The melting, assimilation, and subsequent eruption
of subducted slab material has influenced Oregon geology for
millions of years.