198 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[no. 228. 
E. Biotite-daeite, one-fourth mile north of Old Dominion mine. 
Toscanose. Contains plagioclase, sanidine, quartz, biotite, hornblende, 
apatite, titanite, zircon, magnetite, and glass. P. R. C. 1299. 
F. Quartz-mica-diorite, Florence stage road, 2 miles south of Pinal 
Peak. Tonalose. Contains labradorite, quartz, biotite, microcline, 
muscovite, titanite, apatite, magnetite, and zircon, with secondary chlo- 
rite, epidote, sericite, calcite, and a little hornblende. P. R. C. 1295. 
G. Quartz-mica-diorite, 2 miles south of Hog Ranch, Pinal Moun- 
tains. SB. 3 of vaalase. Contains labradorite, quartz, biotite, ortho- 
clase, muscovite, magnetite, titanite, apatite, and zircon, with 
secondary epidote, sericite, and chlorite. P. R. C. 1296. 
H. Olivine-diabase, 1 mile northwest of Black Peak. Auvergnose. 
Contains plagioclase, augite, olivine, biotite, iron ore, apatite, and 
titanite, Perfectly fresh. P. R. C. 1298. 
E. 
F. 
G. 
H. 
SiO, 
68. 76 
15. 48 
2.50 
.44 
.56 
2.23 
3.89 
3. 88 
.79 
.57 
.50 
.03 
.06 
.03 
.02 
.08 
none 
none 
none 
58. 74 
16.02 
4.16 
3.50 
2.18 
5.12 
3.26 
2.39 
.83 
1.60 
1.29 
.05 
.56 
undet. 
.22 
.10 
trace 
trace? 
61.99 
15.81 
3.28 
2.69 
2.24 
4.62 
2.73 
2.51 
.91 
1.99 
.94 
.03 
.11 
undet. 
trace 
.06 
undet. 
undet. 
trace 
49.00 
ALA 
16.87 
Fe 2 C. 
2.09 
FeO 
8.50 
MgO 
CaO 
6.70 
10.21 
Na 2 ... 
2.57 
K„<> 
.66 
U. 2 at 105° 
.72 
H.,0 above 105° . ..... 
1.00 
TiO., 
1.11 
ZrO, 
.02 
P 2 5 
.13 
CI 
.05 
MnO 
BaO 
.10 
trace 
SrO 
none 
NiO 
none 
Cr 2 3 
.02 
V 2 O s _ 
trace 
s 
none 
none 
.11 
trace 
trace 
none 
FeS, 
Li 2 
undet. 
undet. 
99.82 
100. 13 
99.91 
99.75 
