Map showing large areas of the western North American continent that are accreted.

Accreted terranes of western North America. Everything that is not the “Ancient continental interior (craton)” has been smeared onto the side of the continent by accretion from subduction.

Source: USGS, modified from illustration provided by Oceanus Magazine; original figure by Jack Cook, Woods Hole Oceanographic Institution; https://pubs.usgs.gov/gip/dynamic/Pangaea.html