Revieus — Geological Survey of Canada. 177 



sionally including limestone or more or less calcareous or dolomitic 

 materials and conglomerates. Sheets of contemporaneous trap also 

 occur, pi'obably at several horizons." 



An instructive section of the Cambrian formation, with a thickness 

 of about 3000 feet, was met with near Waterton Lake, and in the 

 eastern part of the South Kootanie Pass. But between the latter 

 and the Flat-head Eiver these beds were calculated to have a 

 minimum thickness of 11,000 feet, and this "included neither the 

 summit nor the base of the series." 



The similarity both as respects their lithological characters, and 

 the general absence of life, of the Cambrian of this part of the 

 Rocky Mountains, to that of the Wasatch Mountains in Utah, and to 

 the same rocks of the Chuar and Grand Caiion Groups of the Colorado 

 Caiion in Arizona, is pointed out by the author. Mr. C. D. Walcott 

 (Amer. Journ. Sci. vol. xxvi. p. 437) has suggested that the absence 

 of the Lower Cambrian Fauna in the western part of the Continent 

 of North America may be due to a land barrier having existed at 

 that time between the eastern and western portions of the continental 

 area. But Dr. Dawson remarks that " the body of water in which 

 the lower portion of the rocks here described were deposited was 

 a basin separated from the ocean, and, occasionally, if not continuously, 

 in the condition of a saturated brine, and this may in itself explain 

 the absence of life of any kind, at least in this particular region." 



Between the Cambrian series and the " Devono-Carboniferous " 

 rocks which succeed, and rest unconformably upon them, there is an 

 interval which, is in part at least filled up in the north-western 

 portion of the area by a mass of beds of " Silurian and possibly 

 also of Cambro-Silurian [Ordovician] age." 



The " Devono-Carbonifei'ous " series attains an estimated thickness 

 of from one thousand to four thousand feet and "forms many of the 

 most prominent ranges and mountain masses." This great limestone 

 series is overlaid unconformably by rocks which are upon strati- 

 graphical, in the absence of palgeontological, evidence deemed to be 

 of Triassic age, and are here " probably the northern limit of a great 

 Triassic mediterranean sea, which extended far to the southward in 

 the western part of the present continental area." 



The Cretaceous rocks are next in ascending order, and belong to 

 the lower division of that group, here named by Dr. Dawson the 

 " Kootanie Series," though showing, according to Sir J. W. Dawson, 

 who examined the plants, consisting of Ferns, Cycads, and Conifers 

 (with, one exception the only fossils collected), affinities with the 

 Jurassic of the Amur country of Siberia, and of the Lower Creta- 

 ceous of Greenland, as these floras have been described by Heer." 



The sandstones, shales, and conglomerates composing the Kootanie 

 Group are estimated to be about 9000 feet in thickness. 



Important Coal-bearing rocks occur in this series, and their dis- 

 tribution is depicted upon a coloured geological map of part of the 

 " Cascade Coal Basin." The coal is an anthracite of excellent 

 quality, and its proximity to the Canadian Pacific Railwaj' line will 

 cause it to be soon tui'ned to account. 



DECADE III. VOL. lY. NO. IV. 12 



