12300'W 



3800'N 



37 30' 



37 



Bodega Bodcgu Ba\ 

 Head 



12230' 

 I 



12200' 

 I 



20 MILES 



Tomales Bay 



San 

 Pablo 

 Bay 



20 KILOMETERS 



un Bav 



Point 

 Reyes 



Bolinas 



Lagoon Mount 



\ Tamalpais 



Richmond 



Mount 

 Diablo 



Farallon 

 Islands 



PACIFIC 



OCEAN 



G 



SAN T 

 FRANCISCO 



OAKLAND 

 Alameda 



Half Moon 

 Ba\ 



<z 







Ano 

 Nuevo 



SAN JOSE 



Mount 



Hamilton. 



Santa 

 Cruz 



The Gulf of the Farallones lies in the offshore part of the San Fran- 

 cisco Bay region (see map at left) just beyond the Golden Gate (views 

 above|. A, View eastward from the Marin Headlands toward the 

 Golden Gate Bridge and downtown San Francisco; Alcatraz Island can 

 be seen at the upper left, Treasure and Yerba Buena Islands and 

 the San Francisco Bay Bridge are seen in the middle distance, and 

 the hills of the heavily populated east bay, which includes the city 

 of Oakland, can be seen beyond the Bay Bridge, fi View westward 

 through the Golden Gate looking out into the Gulf of the Farallones. 

 C, Closeup westward view of the Marin Headlands taken from a 

 similar vantage point as photograph A the headlands are mostly 

 composed of Franciscan chert and pillow basalts (see next page). 

 (U.S. Geological Survey photographs by Phil Stoffer.) 



Regional Setting 9 



