360 
ANALYSES OF EOCKS, U. S. GEOLOGICAL SURVEY. 
WISCONSIN. 
[no. 228. 
Clays, etc., described by Chamberlin and Salisbury in 6th Ann., pp. 
250 and 282. Analyses by R. B. Riggs, record Nos. 259, 260, 261, 202. 
290, 295. Dried at 100°. 
A. Residuary clay from Dodgeville, 4i feet below surface. 
B. The same, 8i feet below surface. 
C. Residuary clay from near Cobb, 4i feet below surface. 
D. Same as C, 3i feet below surface. 
E. Red, putty-like clay, containing pebbles, Milwaukee. 
F. Red pebble clay, Milwaukee. 
A. 
B. 
c. 
l). 
E. 
F. 
Si0 2 
71.13 
1 2. 50 
5. 52 
.45 
.38 
.85 
2.19 
1 . 61 
4.63 
.45 
.02 
.04 
.43 
.19 
49. 59 
18. 64 
17.19 
.27 
.73 
.93 
.80 
.93 
10.46 
.28 
.03 
.01 
.30 
.34 
49. 13 
20.08 
11.04 
.93 
1 . 92 
1.22 
1 . 33 
1.60 
11.72 
.13 
.04 
.06 
.39 
1.09 
53. 09 
21.43 
8. 53 
.86 
L.43 
. 95 
1 . 45 
. 83 
10.79 
.16 
.03 
.03 
.29 
.22 
40.22 
8.47 
2.83 
.48 
7.80 
15.65 
.84 
2. 36 
1.95 
.35 
.05 
trace 
18.76 
.32 
.13 
.06 
4S. 81 
A1 2 3 
7.54 
Fe 2 () 3 --- 
2. 53 
FeO - 
.65 
MgO 
7.05 
CaO 
11.83 
Na 2 
.92 
K 2 
2.60 
H 2 
2.02 
Ti0 2 
.45 
P 2 0, 
.13 
MnO 
.03 
co 2 
15.47 
C, organic. . . 
.38 
S0 3 
.05 
CI 
.04 
100. 39 
100. 50 
100. 68 
100.09 
100. 27 
100. 50 
