Tectonic patterns and histories of parts of the northeast Pacific and California appear to be essentially unrelated, although both regions have been undergoing deformation for most of the past 100 m.y. This situation is indicated by contrasting the nearly east-west crustal shortening resulting from telescoping of the American and Pacific plates according to the new global tectonics, and the nearly north-south crustal shortening evidenced by the San Andreas strain system. Furthermore, none of the oceanic structures are known within the continental crust, nor can any of the continental structures be convincingly extended into the oceanic crust. Nor is there evidence that the San Andreas is a transform fault, or that it separates major crustal plates. Therefore, it seems pro ably that a tectonic discontinuity separates these two regions. It seems improbable that sea-floor movements, comprising expansion of the Atlantic and/or contraction of the Pacific, have caused Cenozoic deformation in this part of North America.