Wanderlust World Wanderlust World There is no oceanic crust along the coastline of San Francisco. The city sits on the North American Plate, which is composed of continental crust. The boundary between the North American Plate and the Pacific Plate (oceanic crust) lies offshore, along the San Andreas Fault system. The oceanic crust of the Pacific Plate is found beneath the Pacific Ocean, west of the continental shelf. The crust immediately offshore is young (formed at the East Pacific Rise), but the coastline itself is on ancient continental crust.