152 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [no. 22 
9. BEARPAW MOUNTAINS. 
Described by Weed and Pirsson, Amer. Journ. Sci., 4th series, vol. 
1, pp. 283 and 351, and vol. 2, pp. 136 and 188. Analyses by H. N. 
Stokes, record Nos. 1558 and 1572. 
A. Quartz-syenite-porphyry, Gray Butte. JVordmarkose. Con- 
tains anorthoclase, microlites of plagioclase, segirite, augite, quartz, and 
apatite, with an occasional zircon and very few biotite leaves. P. R. C. 
897. 
B. Quartz-syenite, Beaver Creek stock. Liparose. Contains ortho- 
clase, albite, quartz, augite, and iron oxides, with very little biotite^ 
hornblende, and sphene. P. R. C. 900. 
C. Basic syenite or monzonite (yogoite), Beaver Creek. Monzonose. 
Contains orthoclase, plagioclase, diopside, biotite, iron oxides, and 
apatite, P. R. C. 902. 
Si0 2 
A1 2 3 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 at 110° 
H 2 above 110° 
TiO, 
PA 
MnO 
SrO 
BaO 
Li 2 
S0 3 
CI 
F 
66.22 
16.22 
1.98 
.16 
. 77 
1.32 
6.49 
5.76 
.08 
.24 
.22 
.10 
trace 
.06 
.29 
trace 
.02 
.04 
trace 
99.97 
B. 
68.34 
15.32 
1.90 
.84 
.54 
.92 
5. 45 
5.62 
.15 
.30 
.21 
.13 
.07 
.04 
.08 
none 
trace 
.04 
none? 
99. 95 
52. 81 
15.66 
3. 06 
4.76 
4.99 
7.57 
3. 60 
4.84 
.16 
.93 
.71 
.75 
trace 
.09 
.24 
trace 
trace 
.07 
trace 
100. 24 
