94 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SUEVEY. 
[bull. 168. 
L. Hornblende-mica-andesite-porphyry dike, ridge south of Hurri- 
cane Ridge. Contains plagioclase, hornblende, biotite, augite, hyper- 
sthene, and magnetite, with a little chlorite or serpentine. Analysis 
by Eakins, No. 1087. 
M. Quartz-diorite-porphyry, Hurricane Ridge. Contains plagio- 
clase, orthoclase, quartz, augite, hypersthene, magnetite, and a little 
biotite. Analysis by Melville, No. 1234. 
N. Quartz-mica-diorite, Hurricane Ridge. Contains andesine, ortho- 
clase, quartz, biotite, hornblende, magnetite, and a little pyroxene. 
Analysis by Melville, No. 1234. 
O. Quartz -mica-diorite-porphyry, Hurricane Ridge. Contains ande- 
sine, orthoclase, quartz, and biotite. Analysis by Melville, No. 1234. 
P. Aplite dike, Hurricane Ridge. Contains quartz, orthoclase, oligo- 
clase, biotite, magnetite, some chlorite, and a little hornblende. Analy- 
sis by Eakins, No. 1088. 
SiO, 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 at 100° . . 
H,0 above 100 c 
Ti0 2 
PA 
MnO 
NiO 
CI 
61.16 
16.17 
2.89 
2.18 
3.89 
4.26 
3.87 
3.20 
2.09 
.23 
.13 
trace 
100. 0/ 
63.42 
17. 16 
3.09 
1.50 
1.64 
4.65 
4.51 
3.04 
.16 
:28 
.35 
.26 
.04 
.19 
100. 29 
63.97 
15..78 
2.35 
1.87 
2.84 
3.71 
4.36 
4.01 
.09 
.49 
.48 
.40 
.05 
trace 
100. 40 
64.40 
15. 77 
2.47 
1.15 
2.12 
3.54 
4.10 
3.81 
.31 
1.93 
.40 
.16 
.04 
.17 
100. 27 
71.62 
14.99 
1.27 
1.01 
.74 
1.33 
3.62 
4.81 
.41 
.08 
trace 
.17 
trace 
100. 05 
