102 



GEOLOGICAL SURVEY OF THE TEERITOEIES. 



total thickness varying from about 200 to 400 feet in thickness. The 

 following sections will best illustrate these beds : 



Section of Cretaceous No. 2 at Little Thompson Creelc. 



No. 



Nature of strata. 



Thickness 

 in feet. 



Dark, thinly laminated crumbling shales, some slates 1 to 3 feet thick, 

 with iaterlaminated beds 6 to 18 inches thick, of fine compact 

 drab argillaceous limestones 



Black, finely crumbling, argillaceous shales, some slates, and few 

 light-snuff-colored sandstones cleaving in slabs - 



Light-yellow and snuff-colored siliceous sandstone 



Black, crumbling shales, with broken and jointed argillaceous sand- 

 stones 



Fine black, crumbling shales, with brown sandstones 1 to 3 feet 

 thick 



Total, (about) 



50 



165 

 5 



60 



120 



400 



Section of Cretaceous JVb. 2 at Bear Cation. 



No. 



Nature of strata. 



Thickness 

 in feet. 



Light, calcareous shales 



Argillaceous limestone 



Covered (pit sunk for coal) black argillaceous shale (?) 



Total, (about) 



12 



5 



100 



120 



It will be observed that between the Big Thompson and Bear Caiion 

 a decided change has taken place, not only in thickness, but also in 

 character. At Kalston Creek the argillaceous element again predomin- 

 ates, there being light-gray shales below, and very black argillaceous 

 shales near the upper part of the series. At Bear Creek these beds are 

 also mostly argillaceous in character, and are about 250 feet thick. Be- 

 tween Bear and Turkey Creeks small amounts of brown iron-ore in con- 

 cretions have been obtained in the shales of No. 2. Here, also, upon 

 the outcropping edges of No. 2 are some small lakes impregnated with 

 carbonate and sulphate of soda to the extent of 33 per cent. They are 

 described by Dr. Hayden in his report for 1869, page 137. The analy- 

 sis of the salt from the evaporated water, by Persifor Frazer, jr., was 

 as follows :* "A white, efflorescent salt, falliDg to powder'ou exiDOSure 

 to the air, and containing— 



Sulphate of soda , 63. 87 



Sulphate of lime 9. 70 



Chloride of sodium, sulphate of magnesia, &c 4. 55 



Water of crystallization of the efflorescence 21. 88 '' 



CRETACEOUS No. 3. 



Cretaceous No. 3 forms, like No. 1, another excellent horizon for refer- 

 ence. Though forming a ridge not nearly so well marked nor so per- 



Hayden's Report, 1870, p. 187. 



