UPPER CRETACEOUS. 



693 



the series, truly marine fossils. They hold also in some layers abundance of fossil plants, and 

 in appearance and degree of induration much resemble the older Carboniferous rocks of some 

 parts of eastern America. Coals of a workable character have been found only in the lower 

 part of the Cretaceous series, which is represented with closely similar characters in the Comox 

 and Nanaimo areas. The somewhat variable character of the Cretaceous measures as a whole- 

 is, however, shown by the fact that Mr. Richardson found it necessary to adopt a different 

 scheme of subdivisions for the two areas, notwithstanding their general correspondence. The- 

 sections at Comox and Nanaimo are as follows, in descending order: ^ 



The age of the productive coal measures of Nanaimo and Comox is approximately that of 

 the Chico group of California, in which, however, in its tjrpical locality, coals are not foxuid. 



M 11. CANADIAN BOOKIES, ALBERTA AND BRITISH COLUMBIA. 



George M. Dawson '^^^^ classified and described the Cretaceous of the Canadian 

 Rockies as follows : 



The sections representing the upper part of the Cretaceous rocks of the mountains are, 

 unfortunately, very unsatisfactory, the best being that of the Northwest Branch. * * * 

 The volcanic beds are there followed by dark shales which afford a few fossils referred to the 

 Benton group and are estimated to attain a minimum thickness of 1,400 feet. Above these 

 are sandstones and shales, generally of pale tints and possibly several hundred or a thousand 

 feet in thickness, which are supposed to represent the Belly River series of the plains to the east- 

 ward. A concealed area beyond these is presumed to be underlain by the Pierre shales, and 

 still higher in the section are beds referable to the base of the Laramie, with characteristic fossils. 

 The thickness of the Laramie at this place is indeterminate but must, be considerable. * * * 



A provincial general representation of the Cretaceous beds of the moimtains of this region, 

 as compared with those of the plain to the east, may be given as follows, in descending: 



