Baja California Peninsula - Geology

Geology

The Baja California peninsula was once a part of the North American Plate, the tectonic plate of which mainland Mexico remains a part. About 12 to 15 million years ago the East Pacific Rise began cutting into the margin of the North American Plate, initiating the separation of the peninsula from it. Spreading within the Gulf of California consists of short oblique rifts or ridge segments connected by long northwest trending transform faults, which together comprise the Gulf of California Rift Zone. The north end of the rift zone is located in the Brawley seismic zone in the Salton Sea basin between the Cerro Prieto Fault and the San Andreas Fault. The Baja California peninsula is now part of the Pacific Plate and is moving with it away from the East Pacific Rise in a north northwestward direction.

Along the coast north of Santa Rosalia, Baja California Sur is a prominent volcanic activity area.

Volcanoes of the peninsula and adjacent islands include:

• Volcanoes of east-central Baja California

and

• Cerro Prieto
• The San Quintín Volcanic Field
• Isla San Luis
• Jaraguay Volcanic Field
• Coronado
• Guadalupe
• San Borja Volcanic Field
• El Aguajito
• Tres Vírgenes
• Isla Tortuga
• Comondú-La Purísima