Memoirs Cal Acad. 5ci. Vol. m. 



[ARMDLD] PlATE XJO/I. 



Figure a. San Pedro. — San Pedro bluff, looking southwest toward the San Pedro valley, showing lower 

 and upper San Pedro (Pleistocene) strata. (See Diagram D, Plate XXII, for explanation.) 



Photograph by R. Arnold. 



Figure b. San Pedro. — San Pedro bluff north of valley, looking west, showing unconformity between 

 lower and upper San Pedro (Pleistocene) deposits. (See Diagram D, Plate XXII, for explanation.) 



Photograph by Dr. H. W. Fairbanks. 



