ALPINE STRUCTURES IN JASPER PARK 567 



Throiigli the efforts of Dr. C. D. Walcott the Robsoii Peak 

 section is determined to be undoubtedly Cambric in age. This 

 flat-lying pile of quartzites and shales is 10,000 feet in vertical 

 extent — all exposed in a single section and in full view at 

 one time. (See Plate IX.) Early, Mid and Late Cambric ter- 

 ranes are well represented as is indicated by an abundance of 

 characteristic fossils. West of Robson Peak the metamorphosed 

 shales, limestones and sandstones and the schists in vast thick- 

 nesses are mainly Pre-Cambrian in age. East of this point clear 

 to the plains Paleozoics chiefly prevail. Of these the Cambric 

 quartzites are easily recognizable after once seen. They seem 

 to occupy the section for a distance of 50 miles east of Robson 

 Park the width of the belt averaging about 40 miles. The Ordo- 

 vicic section, if represented at all, must be quite thin, being con- 

 fined apparently to a relatively small thickness of black shales. 

 Shales of Siluric age seem to be present. The tremendous devel- 

 opment of the Devonic limestones at once arrests attention and 

 the characteristic organic forms are often prolific. It is not al- 

 ways an easy matter to separate the Carbonic limestones from 

 those of Devonic age. As indicated by fossils Triassic and 

 Jurassic beds appear to be represented. Cretaeic strata, with 

 extensive coal beds are infolded with the Paleozoics. 



Since this Athabasca-Fraser river section is more than 100 

 miles long it may be judged that the thickness of the strata 

 must be very great. No very exact figures are yet available, but 

 something of the enormous thickness may be inferred from the- 

 measurements made along the Canadian Pacific railway, 150 

 miles to the south. There Doctors Daly and Allan give the fol- 

 lowing; and they are now compared with those of the Iowa sec- 

 tion: 



