CORRELATION OF SECTIONS 21 



shaly, and thin bedded siliceous rocks, with the Chamberlain shale 

 horizon of the Belt Mountains section. 



The various correlations outlined are represented in graphic form on 

 the table, the horizon of the upper limit of the Newland limestone, at 

 which the crustacean fauna appears, being taken as the horizon from 

 which to correlate the various sections. Of the sections mentioned all 

 but the Lewis Kange, Cceur d'Alene, and Kootenay sections are overlain 

 by . unconformable Middle Cambrian formations. Only one section, the 

 Belt mountains, has been observed with its base in contact with the 

 Archean. 



Correlation of Montanian with Canadian Sections 



Mr Bailey Willis has shown the intimate relations between the 

 Boundary section of Dr George M. Dawson and the section studied by 

 him, crossing the Lewis and Livingston ranges.* The formations de- 

 scribed by Doctor Dawson are the northward extension of those named 

 by Mr Willis. 



The section of Mr B. G. McConnell, across the "Bocky mountains" 

 near the fifty-first parallel, includes the Bow Kiver series and the Castle 

 Mountain group. The latter is a great series of massive bedded, dolo- 

 mitic limestones, below becoming more shaly, and calcareous above. The 

 included fossils prove the lower portions to be Cambrian and the upper 

 of Ordovician age. 



Of the Bow Biver series Mr McConnell says:f 



''The Bow Kiver group forms the basal member of the section in this part of 

 the mountains, and, as developed along the line of railway, consists mainly of 

 a great series of dark-colored argillites, associated with some sandstones, 

 quartzites and conglomerates. The base is not seen, but the part exposed has 

 an estimated thickness of 10,000 feet. 



"The argillites are usually dark grayish in color, but become greenish and 

 purplish in places, are very impure, and frequently grade into flaggy sandstones, 

 which are often slightly calcareous. 



"The conglomerates characterize more especially the top of the formation, 

 and occur in thick, massive looking bands, alternating with quartzites and 

 shales. They are usually firmly cemented into a hard, unyielding rock, but are 

 also met with in a little consolidated and crumbling condition. 



"The quartzites, like the conglomerates, are mostly found in the upper part 

 of the formation, and sometimes, as in Cathedral mountain, replace the latter 

 altogether. 



* Bull. Geol. Soc. Am., 1902, vol. 13, pp. 318-321. 



t Geol. and Nat. Hist. Survey of Canada, pt. D, Ann. Rep., 1886, pp. 29 D and 30 D. 



