144 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[BULL. 168. 
G. Trachytic phonolite, dike on west slope of Bull Cliff. Contains 
alkali feldspars, nepheline, nosite, sodalite, augite, scanty asgirine, 
brown hornblende, magnetite, sphene, apatite, and sometimes lavenite. 
P. R. C. 624. 
H. Altered phonolite, Washington shaft, Victor. Contains potash 
feldspars, with some alteration to muscovite. Crystals of pyritc and flu- 
orite are visible, but nepheline and aegirine have disappeared. Analy- 
sis hitherto unpublished. P. R. C. 623. 
I. Nepheline-syenite, near the Longfellow mine. Contains alkali 
feldspars, nepheline, sodalite, augite, some asgirine, hornblende, biotite, 
sphene, apatite, and magnetite. Sp. gr. 2.68, 23°. Contains 0.02 
VA. 
J. Nepheline-basalt, Appie Ellen shaft. Much altered. Rich in oli- 
vine, augite, and magnetite. Also contains nepheline, feldspars in 
small amount, and biotite. Sp. gr. 2.99, 23°. 
K. Altered nepheline-basalt, Anna Lee mine. Analysis hitherto 
unpublished and not discussed. 
L. Local facies of a phonolitic mass, Bull Cliff. Contains abundant 
augite, plagioclase, alkali feldspar, magnetite, and a little red-brown 
biotite, with a colorless isotropic base in the darker spots. Analysis 
hitherto unpublished. *P. R. C. 627. Contains 0.03 V 2 3 . 
G. 
H. 
I. 
J. 
K. 
L. 
Si0 2 
59.38 
19.47 
1.60 
1.19 
.36 
1.96 
7.80 
5.83 
.11 
.69 
.58 
.08 
.10 
56.74 
20.30 
1.06 
54.34 
19.23 
3.19 
2.11 
1.28 
4.53 
6.38 
5.14 
.14 
1.17 
1.09 
.27 
.07 
35. 03 
9.80 
5.55 
4.98 
9.78 
15.09 
2.04 
2.16 
.41 
2.05 
2.20 
1.99 
none 
48.61 
20.74 
4.29 
.22 
2.11 
.25 
.16 
.77 
12.10 
7.07 
3.57 
.29 
49.84 
17. 78 
5.86 
2.62 
3.02 
7.35 
5.20 
3.04 
.34 
2.02 
1.43 
.76 
- .03 
A1 2 3 ... 
Fe 2 3 
FeO 
MgO 
CaO 
.23 
.57 
.62 
13.36 
.33 
1.15 
.58 
.25 
.07 
Na 2 
K 2 
H 2 OatllO°... 
H 2 above 110° 
Ti0 2 
R(X 
Zr0 2 
Cr 2 3 
trace 
none 
none 
none 
(?) 
MnO 
.15 
.03 
.13 
trace 
.37 
.22 
none 
trace 
.19 
trace 
.08 
.16 
.24 
trace 
.07 
.28 
undet. 
none 
.06 
.17 
.14 
trace 
none 
trace 
undet. 
7.83 
.38 
.21 
.18 
.22 
trace 
none 
trace 
undet. 
.52 
SrO 
BaO 
Li 2 
SO, 
CI.... 
F 
undet. 
.63 
co 2 
♦FeS 2 
4.65 
100. 05 
100. 10 
99.77 
99.66 
100. 81 
100. 42 
