AMERICAN GEOLOGY DECADE OF 1860-1869. 515 



In 1860 J. D. Whitney was appointed State geologist of California 



and served until 1874, when the survey was discontinued. According 



to the original act, he was required to make an accurate and complete 



geological survey of the State and to furnish a report 



Whitney's Geological to ? . J . l 



Survey of California, containing a tul I scientific description ot its rocks, fos- 

 sils, soils, and minerals, and of its botanical and zoo- 

 logical productions. W. H. Brewer was principal assistant in botany 

 and agricultural geology. William Ashburner in mining, and W. M. 

 Gabb, paleontologist. Clarence King also rendered assistance in a 

 volunteer capacity. 



The results of this survey are embodied in three volumes on geology 

 and paleontology published by the State and two volumes on the aurif- 

 erous gravels, published b} r the Museum of Comparative Zoology at 

 Harvard after Whitney's retirement. It was announced in the state- 

 ment of progress for 1872-73 that a geological map of the whole State 

 had been colored, but it seems never to have been published. 



The first volume of Whitney's report of progress and a s\"nopsis of 

 field work from 1860 to 1864 appeared in 1865. This comprised a 

 small quarto volume of 498 pages. The volume contained a great 

 amount of descriptive matter relating to the areal geology of various 

 parts of the State, particularly of the Coast Ranges and Sierra 

 Nevada, with a chapter on the mining regions. 



Whitney decided, from the discovery of a single shell in the rooks 

 of Alcatraz Island, that the so-called San Francisco sandstone was of 

 undoubted Cretaceous age. The serpentines of Mount Diablo and the 

 San Francisco peninsula he considered as metamorphic sediments 

 (sandstone) — a mistake which was later repeated by Becker in his 

 vol iime on the quicksilver deposits of the Pacific slope. 



Whitne} T was decidedly pessimistic regarding the probability of the 

 occurrence of petroleum on the Pacific coast, and unhesitatingly dis- 

 couraged the promoting of enterprises of this nature. With reference 

 to the region south of the Bay of Monterey, he wrote: 



As the bituminous shales are everywhere turned up on edge and have no cover of 

 impervious rock, the inference is unavoidable that flowing wells, or at least those 

 delivering any considerable quantity of liquid petroleum, can not be expected to be 

 got by boring to any depth. The probabilities, at least, are against it. 



When one reflects that the output of the California fields in 1891) 

 amounted to 2,677,875 barrels, he is led to question the infallibility of 

 Whitney's judgment in these matters. 



Whitney considered all those chains or ranges of mountains in Cali- 

 fornia to belong to the Coast Ranges which had been uplifted since 

 the deposition of the Cretaceous formation; those which were elevated 

 before the Cretaceous as belonging to the Sierra Nevada. The slates 

 of the western slope in Mariposa County were regarded as of Jurassic 

 age, and the Calcareous slates of Plumas Count} 7 as belonging to the 



