Pasadena orogeny over is caused by the collision of the North American Plate with other geologic structures that are attached to the Pacific Plate. This orogeny has resulted in the uplift of mostly north-south trending mountain chains, although some east-west trending uplifts are also found such as the Channel Islands and the Transverse Ranges; much of the uplift took place at the edge of basins. The Pasadena orogeny is accompanied by earthquake activity, which includes tsunami hazards. Folding accompanying the uplift of the Coast Ranges in Southern California, folding farther north at Morro Bay and the structure of the Santa Barbara Basin
Sonoma orogeny arcs, composed of volcanic and volcaniclastic strata and paired geotectonically with Sonoma accretionary prisms to the east, are present in the Klamath-Sierran region of the Cordilleran orogen to the south of volcanic cover in the Pacific Northwest. Burchfiel and Davis presented a detailed model relating the Sonoma orogeny to convergent plate tectonic processes. They postulated an east-dipping subduction zone beneath a magmatic arc to the west of the continent. In this scheme, a back-arc basin floored by oceanic crust lay between the arc and the continent. The Sonoma orogeny involved closure of this basin and a process by which the