CLARKE.] 
SANDSTONES. 
24 ( .) 
F. Potsdam sandstone, Ablemans, Sauk County, Wisconsin. De- 
scribed by Diller in Bull. 150, p. 80. Analysis by Schneider, record 
No. 1280. P. R. C. 15. 
G. Banded sandstone, Peoa, Utah. Described by Diller in Bull. 
150, p. 80. Analysis by Schneider, record No. 1280. P. R. C. 16. 
H. Brown sandstone, Flagstaff, Arizona. Analysis by T. M. 
Chatard, record No. 1111. 
1. Sandstone, Robinson mine, Summit County, Colorado. Analysis 
by L. G. Eakins, made in the Denver laboratory, partial. 
F. 
G. 
H. 
J. 
Si0 2 
9<).42 
!■ •« 
96.60 
| 2.02 
.08 
.04 
a 79. 19 
1.30 
2.45 
.23 
7.76 
56.33 
. 77 
.97 
7.30 
14.01 
undet. 
undet. 
undet. 
undet. 
619.04 
A1 2 3 
Fe 2 3 
MgO 
CaO 
Na 2 
K 2 
H 2 at 100° 
} - 
.11 
.29 
.32 
2.94 
5.77 
H 2 above 100° 
C0 2 
99.91 
99.14 
99. 96 
98.42 
a Silica and insoluble matter. 
b Calculated for bases. 
