tHE GRAND CANYON OF THE COLORADO. BAA 
5. Black argillaceous shale, with chocolate and greenish, sandy 
and argillaceous shales beneath, carrying hard layers of 
sandstone. In a few localities white and pink gypsum occurs 
in masses a few feet in diameter, or as seams in the upper, 
black shales - - - = - - - 
. Three feet of compact, mottled, buff limestone interbedded 
in 15 feet of brown sandy shale - - - - 
. a. Black and chocolate, sandy and argillaceous shales, with 
three thin layers of limestone near the base - - 
6. Black and brown argillaceous shale, with interbedded 
layers of a somewhat friable sandstone — - - - 
c. Chocolate, green, maroon, drab, argillaceous shales, with 
thin layers of brownish sandstone interbedded, and, 
toward the base, sandy shales - - - - 
d. Brown sandstone, in layers 8 to 18 inches thick, passing 
below to sandy and argillaceous shales, with layers of buff 
and chocolate sandstone - - = - - 
e. Drab argillaceous shale, passing down into brown, sandy, 
ripple-marked shales - - - - - 
. a. Massive band of irregular, thinly bedded limestone, gray 
and buff except near the chocolate-colored upper stratum. 
A variety of limestone occurs. 
Ss 
. Chocolate-colored, compact layers, with a smooth, partially 
conchoi dal fracture. 
Evenly bedded, thin layers, hard, lead-colored. 
. Thin, shaly, gray layers. 
SNe 
Very irregular and concretionary layers. 
Jj. Compact, gray, bituminous layers. 
Total - - - - - - 
. Dark argillaceous shale, with a strongly marked band of a 
deep-maroon color; drab, yellowish-green, and dark or 
brownish-black shales continue below to a dark-chocolate 
band that is superjacent to 100 feet of drab and greenish 
shales. The shales are largely argillaceous, with arenaceous 
matter scattered through the section as sandy shales, thin- 
bedded sandstone, and arenaceo-argillaceous shales. In one 
locality a band of fine-grained gray limestone, 6 inches thick, 
occurs in the shales 3 inches above the base of the Chuar 
terrane 5 - = = = - = - = > 
Total thickness of lower division - - = ns 
Feet. Feet. 
mele) 
18 
180 
180 
360 
55 
55 
—— £30 
50 
450 to 650 
