134 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [bull. 168. 
C. Socialite from A. Sp. gr. 2.265. 
D. Analcite from A. Sp. gr. 2.255. 
In addition, the orthoclase gave 3.88 per cent Na 2 and 11.03 per 
cent K 2 0. A separation of mixed feldspars, sp. gr. 2.56, gave 6.08 per 
cent Na 2 and 8.91 per cent K 2 0. 
A. 
B. 
c. 
D. 
Si0 2 
56. 45 
20.08 
1.31 
4.39 
.63 
2.14 
5.61 
7.13 
.26 
1.51 
.29 
.13 
trace 
.09 
.43 
38. 41 
17.65 
3.75 
21. 75 
2.54 
10.52 
2.95 
1.95 
41.56 
29.48 
49.54 
25. 07 
ALOo 
Fe 2 3 
FeO 
.49 
.15 
.49 
19.21 
.91 
.45 
3.73 
.40 
.20 
.22 
15.32 
.89 
undet. 
undet. 
MgO 
CaO 
Na 2 
K 2 
H 2 at 100° 
H 2 above 100° 
.24 
Ti0 2 
P 9 (X 
NiO 
trace 
.15 
MnO 
CI 
4.79 
1.67 
Less O 
100. 45 
.10 
99.91 
101. 26 
1.08 
93.31 
.38 
i 
100. 35 
100. 18 
92.93 
7. LITTLE ROCKY MOUNTAINS. 
Granite- syenite-porphyry. Described by Weed and Pirsson, Jour- 
nal of Geology, vol. 4, p. 399. Contains orthoclase, quartz, oligoclase, 
iron oxides, and a little muscovite. Analysis by H. N. Stokes, record 
No. 1558. P. R. C. 905. 
Si0 2 
68.65 
18.31 
.56 
.08 
.12 
1.00 
4.86 
4.74 
.27 
.83 
.20 
P 9 0, 
trace 
trace 
.10 
.13 
trace 
trace 
.03 
trace 
A1 2 3 
MnO 
Fe.,0, 
SrO 
FeO 
BaO 
MgO 
Li 2 .. 
CaO 
so 3 
Na 2 
CI 
K 2 
F 
H 2 Oat 110° 
99.88 
H 2 above 110° 
Ti0 2 
