Baja California: The Geology of Rifting

Those of us who live in the Los Angeles region know that this is an area of active tectonics. We have earthquakes; we have many large mountains nearby that are testimony to the great power of the forces that are moving and deforming the surface of the earth here; and we have the San Andreas fault as our local tourist attraction. But this great fault is not just local. Besides extending northward it also continues south toward the Gulf of California, where a series of structures represents its continuation under water. All of these structures are part of the major boundary between the Pacific plate and the North America plate. So even though we don't think of Los Angeles and the Gulf of California as being similar in many ways, they're tectonically connected because they sit on the same plate boundary and suffer many of the same kinds of deformation due to motions between these two plates.