62 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[bull. 16 
E. Phonolite, hill between Black and Big mountains, Uvalde quad 
rangle. Contains sanidine, nephelite, and a^girite, and very littl 
brown hornblende, augite, and magnetite. Sp. gr. 2.559, 19.5°. P 
R. C. 1070. 
F. The portion of E soluble in 1 : 40 dilute nitric acid. 
G. Nepheline-basalt, Tom Munns Hill, Uvalde quadrangle. Con 
tains olivine, augite, nephelite, magnetite, and apatite. Sp. gr. 3.148 
19°. P. R. C. 1065. 
H. The portion of Gr soluble in 1 : 40 dilute nitric acid. 
E. 
F. 
G. 
H. 
Si0 2 
54.42 
20.76 
2.64 
1.33 
.22 
1.34 
10.41 
4.89 
.22 
2.50 
.40 
.11 
.15 
none 
none 
.15 
trace 
.04 
trace 
.01 
26.90 
14.34 
40.32 
a 9. 46 
4.75 
7.48 
18.12 
10.55 
2.62 
1.10 
.57 
1.25 
2.66 
.68 
none 
12.27 
6.09 
A1 2 3 
Fe 9 Oo 
FeO 
.60 
(?) 
.30 
8.32 
1.22 
(?) 
(?) 
2.83 
6.48 
1.45 
2.39 
.93 
(?) 
(?) 
MgO 
CaO 
Na 2 
K 2 
H 2 at 110° 
H 2 above 110° . 
Ti0 2 
P„0*--. 
.11 
.68 
Zr0 2 
Cr 2 3 .. 
NiO . 
.06 
.25 
.03 
.06 
trace 
.01 
.03 
.05 
.04 
MnO 
SrO 
BaO 
Li 2 
S 
S0 3 
CI 
.23 
none 
F . 
Less O. 
99.82 
.05 
51.79 
100. 09 
.03 
33. 12 
99.77 
100.06 
a Including Cr 2 3 
