san andreas fault geology definition
1. San Andreas Fault-a major geological fault in California; runs from San Diego to San Francisco; the source of serious earthquakes. Calif. , California, Golden State, CA-a state in the western United States on the Pacific; the 3rd largest state; known for earthquakes. Translations.
Map of the San Andreas Fault, showing relative motion. The San Andreas Fault is a continental transform fault that extends roughly 1300 km (810 miles) through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip (horizontal).