224 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [bull, 168. 
WASHINGTON. 
Rocks from the Mount Stuart quadrangle, Kittitas County. Col- 
lected by George Otis Smith, who furnishes the petrographic data. 
Hitherto unpublished. Analyses A, B, C, F, and G by H. N. Stokes, 
record No. 1836; D, E, H, and I by W. F. Hillebrand, record No. 1831. 
A. Granodiorite, south slope of Mount Stuart. Contains plagio- 
clase, orthoclase, hornblende, biotite, quartz, and magnetite. 
B. Granodiorite, ridge between Hardscrabble and Cascade creeks. 
Contains plagioclase, orthoclase, biotite, hornblende, quartz, magne- 
tite, and apatite. 
C. Granodiorite-porphyry, dike 2 miles west of Mount Stuart. Con- 
tains plagioclase, biotite, hornblende, orthoclase, and quartz. 
D. Serpentine, Three Brothers. Derived from saxonite. Contains 
serpentine, bastite, magnetite, and pyrite. 
E. Metamorphic rock, head of Beverly Creek. Believed to be de- 
rived from an inclusion of limestone in the peridotite. 
Si0 2 
A1 2 3 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 OatllO°.... 
H 2 above 110° 
Ti0 2 
PA 
Cr 2 3 
NiO 
MnO 
SrO 
BaO 
CO,.. 
s 
FeS 2 a 
64.04 
15.58 
1.26 
3.22 
3.23 
"4.51 
4.01 
2.22 
.19 
1.17 
.69 
.16 
none 
none 
trace 
trace 
.11 
trace 
none 
trace 
100. 39 
B. 
63.37 
15.90 
1.41 
3.18 
3.33 
4.63 
4.05 
2.10 
.18 
1.16 
.69 
.17 
none 
none 
trace 
none 
.06 
trace 
none 
trace 
100. 23 
c. 
63.78 
16.39 
1.12 
2.76 
3.27 
4.07 
3.84 
2.03 
.22 
1.82 
.44 
.11 
none 
none 
.05 
trace 
.08 
trace 
none 
trace 
39.00 
1.75 
5.16 
1.71 
38.00 
trace 
.10 
1.31 
12.43 
trace 
trace 
.47 
.10 
.15 
none 
none 
none 
none 
.03 
100. 21 
32.12 
.82 
2.05 
3.50 
26.73 
1.81 
.06 
.43 
.98 
trace 
trace 
.27 
.08 
.14 
none 
none 
31.04 
none 
100. 03 
a Actual condition of sulphur not known. 
