364 ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [no. 228. 
COLORADO. 
A. Loess, Denver. 
B. Loess, Highland. 
C. Concretion in loess, Wray. 
A, B, and C collected by S. F. Emmons. Analyses by L. G. Eakins, 
record No. 1066. 
D. Clay, Davis ranch, Pueblo quadrangle. 
E. Clay, head of Rock Creek, Pueblo quadrangle. 
D and E collected by G. 'K. Gilbert. Analyses by George Steiger, 
record No. 1457. 
Si0 2 . 
ALO, 
FeO 
MgO 
CaO 
Na 2 
K 2 () 
H 2 Oatl00°... 
H 2 above 100 c 
Ti0 9 
P 2 5 
MnO 
C0 2 
Organic matter. 
A. 
69.27 
13.51 
3.74 
1.02 
1.09 
2. 29 
1.70 
3.14 
4.19 
.45 
trace 
trace 
100. 40 
60. 97 
15.67 
5. 22 
. 35 
1 . 60 
2.77 
.97 
2.28 
9. 83 
.19 
trace 
.31 
100. J i 
3.7^ 
20 
2.59 
100. 24 
63.52 
24.72 
.43 
.13 
.30 
trace 
trace 
1.58 
8.41 
.68 
trace 
40 
ioo. 1: 
76. 56 
8.30 
.38 
.24 
.12 
trace 
trace 
1.26 
4.40 
.60 
.06 
8.31 
100. 23 
