Geology
The Farallon Islands are outcroppings of the Salinian Block, a vast geologic province of granitic continental crust sharing its origins with the core of the Sierra Nevada Mountains. The block was torn off far to the south of its present position and rifted north by the movement of the Pacific Plate on which the islands rest. Other nearby examples of the Salinian Block include the Point Reyes Peninsula and Bodega Head. The San Andreas Fault, marking a boundary zone between the Pacific and North American Plates, passes a few miles east of the islands.
The historic Farallon Plate is named after the islands.
Read more about this topic: Farallon Islands