630 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



Many layers here become calcareous from the inclusion of organic remains, of which some are 

 evidently shells, though too poorly preserved for recognition, except in the case of one or two 

 specimens, which appear to be Ostrese. 



The base of the Cretaceous consists of tufaceous beds with ordinary sandstones 

 and calcareous layers that contain many fossils. "These, while in some cases 

 specifically identical with those of subdivision C, include a few species not yet found 

 in that part of the section, and thus present a general facies somewhat different 

 from it." 



The fossils from the Cretaceous of the Queen Charlotte Islands are described by 

 Whiteaves.'^^ 



Dawson discussed the relations of the Queen Charlotte group and the Kootenai 

 (Lower Cretaceous) of British Columbia, and reached the conclusion that "The 

 very important fact is established of the existence of an identical earlier Cretaceous 

 horizon on the west coast, and in and even to the east of the eastern range of the 

 Cordillera system." 



Stanton states (orally) that Dawson's reasoning was based chiefly on marine 

 mollusks occurring below the plant-bearing beds of the Kootenai, in the Fernie 

 formation, which is now assigned'to the Jurassic. (See Chapter XII, under N 8-9, 

 table of formations by Dawson, p. 540.) 



N 9. TELKWA BIVEE, DISTRICT, BRITISH COLUMBIA. 



Near the center of the large area mapped as Lower Cretaceous in British 

 Columbia is Telkwa River, which traverses a district surveyed by Leach/^^ who 

 thus describes the rocks of Dawson's "Porphyrite group" and the overlying coal- 

 bearing strata: 



Rocks of the Porphyrite group occupy by far the most extensive area in this map sheet. 

 They consist of a great series of volcanics, composed of tuffs, andesites, agglomerates, etc., 

 more often occurring in sheets as volcanic flows but frequently showing evidences of deposition 

 under water, more particularly toward the top of the series, and are aU more or less regularly 

 bedded. 



The rocks of this group vary greatly in appearance in different parts of the field, in color 

 ranging from light greenish grays to dark purplish reds. Generally speaking it may be said 

 that red colors predominate toward the top of the series, the beds consisting of reddish andesites, 

 breccias, and tuffs, in many cases amygdaloidal, with inclusions of calcite and zeoUtes. Green 

 is the characteristic color toward the base, the beds being composed largely of fine-grained 

 greenish f eldspathic rocks, often amygdaloidal and containing much calcite and epidote. * * * 



Immediately overlying these rocks, and possibly unconfonnable to them, although both 

 have been subsequently folded and faulted to such an extent that their immediate relationship 

 to one another is somewhat doubtful, occurs a series of beds composed chiefly of clay shales and 

 containing a number of important coal seams. The lower member of these beds consists of a 

 coarse, loosely cemented conglomerate, mainly composed of pebbles from the underlying vol- 

 canics, in places shading into a coarse grit and not more than 60 feet in thickness in any place 

 seen. * * * ipj^ig jg followed by some thin-bedded clay shales with a few soft, thin, crumbly 

 beds of light-colored sandstone, succeeded by more clay shales and coal, carrying numerous 

 yeUow-weathering clay-ironstone nodules. These are the youngest sedimentary rocks repre- 

 sented ra the district, and [are] not of great thickness (in no case seen showing more than 300 

 feet in all) . * * * 



