286 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[bu li 
COLORADO. 
Shales from the Pueblo quadrangle, collected by G. K. Gilbert. 
A, B. Near Nushbaum Spring. 
C. Salt Creek. 
D. Head of Rock Creek. 
E. Near Rush Creek. 
Analyses by George Steiger, record No. 1466. 
Si0 2 . 
A1A 
Fe 2 3 
MgO 
CaO. 
K 2 
H 2 Oatl00°... 
H 2 above 100 c 
TiO, 
co 2 
Organic matter. 
60.80 
15. 63 
4.62 
2.73 
1.63 
1.45 
2.55 
3.19 
4.16 
.47 
.10 
2.87 
100. 20 
51.69 
16.50 
7.90 
2.10 
4.41 
2.07 
2.68 
3.02 
6.00 
.66 
..22 
3.19 
.53 
100. 97 
c. 
60.60 
16.42 
4.95 
1.43 
1.61 
.92 
2.98 
3.91 
5.72 
.35 
.31 
84 
100. 04 
63.60 
16.74 
4.63 
1.19 
.68 
.29 
2.92 
2.88 
5.99 
16 
46 
100. 20 
45.89 
13.24 
3.88 
2.12 
12.09 
.47 
2.31 
1.38 
4.16 
.52 
.17 
10.38 
3.47 
100. 08 
Calcareous shales from Fairplay, Park County. Partial analyses, by 
W. F. Hillebrand, made in the Denver laboratory. 
F. 
G. 
Insoluble 
68.72 
2.10 
35.14 
Fe 9 0-,, ALOo, etc 
FeO, MnO 
2.10 
12.55 
19.34 
.73 
30.28 
MgO 
5.72 
9.06 
1.01 
13. 41 
CaO 
H 2 
C0 2 , calculated 
100. 02 
100. 14 
