EAPID CEEEK SECTION. 125 



five or six miles through a canon whose sides are almost vertical walls of 

 the sedimentary series. The dip, though varying and increasing in the 

 lower end of the canon near the Red Beds, is not very great, being 15° or 

 20°, and the rocks can therefore be studied with considerable ease. The 

 accompanying section is derived from the walls of the canon. 



In ascending order the detailed section is as follows, adhering to the 

 numbers of the beds as given in the above cross-section : 



Carboniferous. 



Feet. 



3. Limestone, pink, gray at top and weathering as though slightly argillaceous . 35 

 Limestone, pink and yellowish, shaly ; containing some cyathophylloid corals . 40 



4. Limestone, gray or white, very massive ; forming cliffs 150+ 



Silicious limestone, pinkish in color, brecciated ; weathering in reddish 



streaks 175+ 



5. Silicious limestones and sandstones alternating in thin beds, pink and red- 



dish in color 200+ 



Impure, massive, white sandstone, stained red 40 



Massive* brecciated sandstone, stained red 30 



Red sandstone, stratified in well-marked strata 40 



The section agrees in the main with the typical Carboniferous section, 

 but the base of the Carboniferous is here thicker than elsewhere in the 

 Hills, and is at the same time a more massive and pure limestone. 



The inter stratified sandstones and limestones of the upper Carbonifer- 

 ous are shown near the mouth of Rapid Creek in great detail, and because 

 of the interest attaching to these beds a careful section was made of the 

 exposure as follows, in descending order : 



Red Beds. 



Feet. 



19. Limestone, purple . 25 



18. Clays, deep red 100 



Carboniferous. 



17. Sandstone, white and stained red, distinctly stratified 40 



16. Sandstone, variegated, deep red ; showing no stratification 30 



15. Sandstone, white and massive, stained red 40 



14. Limestone, pink 3 



13. Sandstone, white and pinkish 3 



12. Sandstone, argillaceous and calcareous, becoming a pink and white sand- 

 stone ... 24 



11. Limestone, purple, impure and argillaceous 3 



