LOWEE CEETACEOUS. 615 



considered as overlying aR of the Kiowa or only a lower part of it, and whether or not they 

 merge southward into the upper part of the Kiowa, are questions that remain still unanswered. 



J-K 10. CALIFORNIA. 



The general character and relations of the Cretaceous of the Pacific coast from 

 southern California to British Columbia are ably discussed by Anderson,^^ who 

 describes and correlates the separate sections and their faunas. 



The Cretaceous of California is divided into the Shasta (Lower Cretaceous, com- 

 prising the Knoxville and Horsetown formations) and the Chico (Upper Cretaceous). 

 They have been described as the " Shasta-Chico series" by Diller and Stanton,^** 

 who give a' comparative table of classifications according to Gabb's, White's, and 

 their own observations, and state : 



The Chico, Horsetown, and Knoxville beds have been found to grade into one another in 

 such a way as to show that they are simply different phases of one continuous series of deposits 

 extending without an important interruption of any kind from the bottom of the Eaioxville 

 to the top of the Chico. For this set of beds the term Shasta-Chico series has been proposed." 



The type section of the "Shasta-Chico series" was measured on Elder Creek, 

 in northern California, and originally stated in detail by DiUer."" The following is 

 condensed from his statement : 



Feet. 



Chico : Massive and thin bedded sandstone, with conglomerates 3, 897 



Horsetown: Sandstones, often thin bedded, and shales 6, 109 



Knoxville: Shales, with calcareous layers in the upper 10,000 feet, interbedded with sand- 

 stones below 19, 974 



Apparent total thickness of unaltered strata [29, 980] 



The Chico (Upper Cretaceous), though generally conformable in the Valley of 

 California to earlier Cretaceous formations where they occur, overlaps them in many 

 localities. This is the case in the section on Chico Creek, in the northeastern part 

 of the Valley of California, where the underlying rocks are metamorphosed aurif- 

 erous slates.^**'' " 



Lists of the faunas from different horizons of the "Shasta-Chico series" are 

 given in the paper by Diller and Stanton ^^* already cited, but Stanton "'• "^ dis- 

 cusses the faunas and also the stratigraphy in two later papers, of which that of 

 1895 assembles the facts of distribution and stratigraphic relations more compre- 

 hensively and clearly. 



The remarkable thickness assigned to the Knoxville formation in Tehama 

 County is in a measure borne out by the observations of Osmont ®^* in the region 

 north of San Francisco Bay: 



The eastern portion of both sections is largely made up of Cretaceous shales and sandstones, 

 most if not all of which probably belong to the lower Cretaceous or Knoxville series.'' 



This series consists of an enormous thickness of rather hard tawny-yellowish sandstone, 

 interbedded in monotonous succession with dark-blue fissile shales, with occasional thin beds 

 of dark-blue hmestone. The sandstone strata are usually less than 2 feet thick, and almost 

 never more than 10, while their regular alternation with soft shale made the bedding very 

 distinct and characteristic. 



» Bull. Geol. Soc. America, vol. 4, pp. 205-224, 245-256. Since the papers referred to were written we have spent 

 several months in the field, completely reviewing the Cretaceous of northern California. The results fuUy confirm our 

 previous views. 



6Becker, G. F., Quicksilver deposits of the Pacific slope: Mon. U. S. Geol. Survey, vol. 13, 1888. 



