21S .1. S. DILLER — GEOLOGY OF CALIFORNIA AND OREGON. 



the Pugel sound region, but of its extent scarcely anything is known. 

 Further northward, however, the same series is extensively developed in 

 Vancouver and Queen Charlotte islands, as well as within the interior 

 portion of British Columbia, where it lias been described by Dr Selwyn, 

 Dr Dawson, and Mr Richardson in the reports of the Canadian geologic 

 survey. From an extensive knowledge of the facts, Dr Dawson concludes 

 that in early Cretaceous times the immediately post-Triassic elevation 

 had been followed by a subsidence of the land, resulting in the reoccu- 

 pation by the open sea of a great area near the Pacific coast and north 

 of the fifty-fourth parallel, spreading eastward in a more or less connected 

 manner completely across the present position of the Cordilleras. The 

 Gold ranges, and probably also many other insular areas, continued to 

 exist as dry land. As local terrestrial conditions are recurrent through- 

 out a great thickness of strata, it is obvious that the subsidence was 

 continuous or nearly so and was followed pari passu by sedimentation. 

 Dr Dawson says : 



"About the stage in the Cretaceous which is represented by the Dakota group, 

 however, a much more rapid downward movement of the laud occurred. This is 

 marked by the occurrence of massive conglomerates, which have been recognized 

 in many places in the southern part of the interior of British Columbia, as well as 

 westward to the Queen Charlotte islands."* 



Dr Dawson calls attention to the tact that west of the axis of the 

 Coast ranges the area of Cretaceous sedimentation was transgressively 

 extending southward, the local base of the Cretaceous being found at suc- 

 cessively higher stages in the system in that direction, till at a time, which 

 is believed to have corresponded with the Laramie of the plains, the sea 

 invaded the Puget sound region. The invasion of the sea in British 

 Columbia was contemporaneous with that of northern California and 

 Oregon just described, and possibly also with that which carried Aueetta 

 around the southern end of the land barrier into Mexico.f 



Tertiary. 



The Tejon beds are now generally regarded as representing the earliest 

 Tertiary deposits of California ami Oregon. In noddle California these 

 beds are well represented. They are not only conformable with the( !hic( >. 

 lint have been considered to form, with the Chico, a continuous series of 

 strata, deposited without any interruption in the process of sedimenta- 

 tion. This is unusual, for generally a fauna! and stratigraphic break 

 occurs between the Cretaceous and Tertiary. 



* Am. .lour. Sri., .",.1 sit., vol. xxxviii, 1880, p. 120; Transactions of the Royal So< iety of Canada, 

 vol. viii, sect, iv, 1S!H>, pp. 8, •>. See also S. F. Emmons, Bull. Geol. Sue. Am., vol. 1, p. 278. 

 fNeues Jarb. fur Min., Geol. u. Pal., ls'ju, ii bund, p. l'v:;. 



