GENERAL CHARACTER AND CORRELATION 713 



monotis subcircularis (sec page 29, figure 1). This is the only fossil 

 recognized in these beds at most localities, although a few fossils have 

 been found associated with the Pseudo monotis at some places. These in- 

 clude Clionites (Shastites) sp. at the head of White River, Area ( ?) sp. 

 on the west coast of Cook Inlet, BliynchoneUa (?) sp. and Terebratulas^. 

 near the mouth of Nation River, and some undetermined pelecypods near 

 Cape Lisburne. 



The presence of Pseudomonotis subcircularis in these beds is sufficient 

 evidence for their approximate correlation with the Brock shale of Shasta 

 County, California, with the Swearinger slate of Plumas County, Cali- 

 fornia, and with the Pseudomonotis-bearing slates and slaty limestones 

 of the West Humboldt Range, Nevada. 



In British Columbia and Yukon there is an extensive development of 

 Pseudomonotis-bearing beds that can be correlated on the basis of faunal 

 content, as well as of stratigraphic sequence, with those of Alaska. They 

 occur (see figure 1) in two well defined belts — a western or coastal belt 

 that includes Triassic areas in the Queen Charlotte Islands, on Vancouver 

 and the adjacent islands, and at the northern end of the Cascade Range ; 

 and an eastern or interior belt that is situated on the eastern front of the 

 Rocky Mountains, and that includes known Triassic areas on Pine, Peace, 

 and Stewart rivers. 



The Pseudomonotis-bearing beds of Queen Charlotte Islands, accord- 

 ing to Dawson, 48 consist of flaggy calcareous argillites and thin limestones 

 more than 1,000 feet thick. These beds are underlain by massive lime- 

 stone and are overlain 49 by feldspathic sandstone, coarse conglomerate, 

 and agglomeratic rocks that Dawson considered Cretaceous, but which 

 are now known to be Lower and Middle Jurassic. 50 These rocks have all 

 been included in the Vancouver series. The contact of the argillites with 

 the underlying limestone, although supposed to be in general conformable, 

 is apparently unconformable, in at least one localit}^, according to Daw- 

 son's description. 51 The fossils listed from these beds include Pseudo- 

 mono tis subcircularis (Gabb), an "extreme local variety" of "Halobia 

 lommeli? '," and Arniotites Vancouver ensis Whiteaves. 



It is probable that the same horizon is present in the Vancouver series 



48 George M. Dawson : Report on the Queen Charlotte Islands. Geol. Survey of Can- 

 ada. Report of progress for 1S7S-1879, 1880, pp. 48B, 55B, 58B, 59B, 61B, 62B, 63B. 

 82B. 



49 George M. Dawson : Report on the Queen Charlotte Islands. Geol. Survey of Can- 

 ada. Report of progress for 1878-187D, 1880, pp. 4SB, 59B, 62B. 



=0 J. D. McKenzle : South-central Graham Island, British Columbia. Summary report 

 of the Geological Survey, Department of Mines [Canada], for 1913, pp. 40-42. 



51 George M. Dawson: Report on the Queen Charlotte Islands. Geol. Survey of Can- 

 ada. Report of progress for 1S78-1879, 18S0, p. 82B. 



