Gulf of california: a result of ocean-floor spreading and transform faulting

Ocean-floor spreading tore southern Baja California from mainland Mexico 4 million years ago and has subsequently rafted it 260 kilometers to the northwest along the Tamayo Fracture Zone. Magnetic-anomaly profiles indicate spreading at the mouth of the gulf at 3.0 centimeters per year and a rise-crest offset of 75 kilometers inside the gulf across the Tamayo Fracture Zone.