NEOCENE STRATIGRAPHY. 279 



PREVIOUS WRITERS. 



The following will show in a general way the develop- 

 ment of our present knowledge on the Coast Ranges, and 

 the Santa Cruz Mountains in particular. Only the more 

 important points are mentioned here, as these and other 

 works will be referred to in detail in subsequent chapters. 



Beechey. — In 1825 to 1828, Captain Beechey* made a 

 voyage to the Pacific and Behring Straits. His notes and 

 collections on the geology of the vicinity of San Fran- 

 cisco were worked up by Professor Buckland. A map 

 is given of the headlands about the Golden Gate, upon 

 which serpentine, sandstone and jasper rock are repre- 

 sented. 



Tyson. — In 1849, Mr. P. T. Tysonf visited California. 

 He notes the presence of sandstones containing a big 

 oyster ( Ostrea titan, Conrad) near Martinez and in Liver- 

 more Valley, and assigns the strata to Eocene or Miocene 

 age. He finds strata which he thinks maybe quite recent 

 or late Tertiary. He describes quite accurately the 

 cherts, jaspers, etc. (phthanites). He notes the presence 

 of hypogene and metamorphic rocks of many kinds, 

 which have been twisted about and mixed together in the 

 most confused manner, and inentions having found in a 

 small space near Bodega Point, gneiss, mica slate, in- 

 durated talcose slate, hornblende slate and serpentine, the 

 last containing chromiferous iron. Near San Diego he 

 notes the extensive diffusion of diluvial drift. 



* Zoology of Captain Beechey's Voyage to the Pacific and Behriug's 

 Straits in 1825-1828. London. 1839. 



t Keport of the Secretary of War, Communicating Information in Eela- 

 tion to the Geologj' and Topography of California. Senate, Ex. Doc. No. 

 47. 1850, pp. 15 et seq. 



