l86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 75 



portion of the Glacier Lake section from the Ghost River pre- 

 Devonian disconformity down through the Sarbach, Mons, and Lyell 

 formations. 



The Upper Cambrian and Ozarkian formations of the Sawback 

 Range, collectively named Sawback formation by Allan/ were hastily 

 examined in Ranger Canyon, 12 miles (19.3 km.) northwest of 

 Banfif in 1920, and found to contain fossils of the Mons and Lyell 

 formations of the Glacier Lake section, and in 192 1 a section that is 

 finely exposed in the amphitheater at the head of Ranger Brook 

 Canyon was measured from the unconformity at the bas|e of the 

 Devonian down through the Mons, Lyell, Bosworth, and Arctomys 

 formations and into the subjacent middle Cambrian Eldon forma- 

 tion. 



During the field season of 1922, a section of the Mons formation 

 was examined near the head of Douglas Lake Creek in the northern 

 part of the Sawback Range. 23.5 miles (37.8 km.) southeast of the 

 Clearwater section and about 14 miles (22.5 km.) northwest of the 

 Ranger Brook section ; also an incomplete section at the southern end 

 of the Brisco-Stanford Range in Sinclair Canyon, British Columbia, 

 41 miles (66 km.) south-southwest of the Ranger Brook section and 

 on the western slope of the main range of the Rocky Mountains. The 

 Sinclair Canyon section indicated a great development of the Mons 

 formation, which caused me to return in 1923 to study it and the pre- 

 Devonian formations of the Beaverfoot-Brisco-Stanford Range be- 

 tween Kicking Horse Canyon on the north and Kootenay River at 

 Canal Flats on the south. The results were published in 1924.° 



In considering the relations of the great lower Paleozoic sections 

 of the Cordilleran ranges in Utah, Nevada, and the Canadian Cordil- 

 lera in 1893 (Bull. U. S. Geol. Surv., No. 81), I realized that there 

 was strong evidence for correlating certain Upper Cambrian and pre- 

 Devonian formations throughout the Cordilleran region from the 

 Bow Valley-Kicking Horse district of Alberta and British Columbia 

 to the Basin ranges of Utah and Nevada, but before discussing this 

 correlation I preferred to wait and study the northern sections and 

 make collections of fossils from well-determined formations on 

 which to base conclusions. In this paper the more or less imperfect 

 reconnaissance sections of Nevada and Utah are referred to for the 

 purpose of comparison with those of the Canadian Cordillera, but 

 it should be understood that a thorough, critical study must be made 



^ Geol. Surv. Canada, Report for 1912 (1914), p. 168. Also Guide-Book No. 8, 

 Pt. 2, Transcontinental Excursions, 1913, p. 182. 

 ^ Smithsonian Misc. Coll., Vol. 75, No. i, 1924. 



