CLARKE.] 
SLATES AND SHALES. 
COLORADO. 
347 
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 . . 
|lA- 
Fe 2 3 - 
MgO . 
CaO . . 
Na 2 ( ) . 
K.O.. 
Ti0 2 
PA 
bo 2 
Organic matter. 
60.80 
15.63 
4.62 
2.73 
1.63 
1.45 
2.55 
3.19 
4.16 
.47 
.10 
2.8, 
100. 20 
B. 
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 
.66 
.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 Count}\ l^artial analyses, by 
W. F. Hillebrand, made in the Denver laboratory. 
Insoluble 
Fe 2 3 , Al A, etc 
FeO, MnO 
MgO 
CaO 
H 2 
CO,, calculated. 
68. 72 
2.10 
35. 14 
5.72 
9.06 
1.01 
13.41 
2.10 
12.55 
19.34 
.73 
30. 28 
100.02 100.14 
