204 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[bull, 168. 
A. Soda-syenite-porphyry, dike east of Moccasin Creek. Consists 
mainly of albite, with a greenish mineral which is probably aegirite. 
Analysis by H. N. Stokes, record No. 1563. P. P. C. 773. 
B. Augite-syenite, dike on Turnback Creek, about 1 mile north of 
Carter post-office. Hitherto unpublished. Contains orthoclase and 
augite, with less plagioclase and quartz. Analysis by Stokes, No. 
1642. 
C. Diorite, dike 1£ miles southeasterly from Sonora. Contains 
feldspar largely altered to hornblende. . A few black grains are prob- 
ably iron ore. Analysis by W. F. Hillebrand, record No. 1548. 
P. R. C. 759. 
D. Quartz-pyroxene-diorite, large area east of Sonora. Contains 
plagioclase, quartz, biotite, augite, rhombic p}^roxene, and a trace of 
iron ore. Analysis by Hillebrand, No. 1548. P. R. C. 760. 
E. Diorite, dike about li miles southeasterly from Sonora. Con- 
tains altered plagioclase and hornblende, with epidote, chlorite, and 
iron disulphide as secondary products. Analysis by Hillebrand, No. 
1548. P. P. C. 761. 
Si0 2 
FeA 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 OatllO° 
H 2 above 110° . 
Ti0 2 
MnO 
MO. 
SrO . 
BaO. 
Li 2 
so 3 . 
co 2 . 
F ... 
FeS 2 . 
67. 53 
18. 57 
1.13 
.08 
.24 
.55 
11.50 
.10 
.15 
.31 
.07 
.11 
trace 
trace 
trace 
trace 
100. 34 
B. 
61.28 
14.71 
1.21 
2.85 
1.69 
5.61 
2.99 
7.70 
.28 
.43 
.41 
.16 
trace 
04 
72 
08 
100. 16 
58. 05 
15.46 
1.69 
5.09 
4.84 
6.94 
2.86 
2.14 
.10 
2.02 
.72 
.16 
.14 
none 
trace 
.07 
trace 
none 
100. 28 
57.80 
16. 43 
1.62 
6.51 
4.14 
7.21 
2.35 
2. 29 
. 11 
.38 
.70 
.19 
.18 
.03 
trace? 
.09 
trace 
100. 03 
53. 46 
14.81 
2.60 
5.15 
7.27 
8.44 
2.64 
1.30 
.12 
2.13 
.70 
.16 
.18 
.05 
trace 
.05 
trace 
44 
.26 
99.76 
