CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
225 
5. SIERRA COUNTY. 
Rocks collected and described by H.W. Turner. See paper in 17th 
Ann., Part I, p. 521. Additional details, supplied by Turner, are given 
here. Analyses A to H by W. F. Hillebrand, record Nos. 1456 and 
1548. Analysis I by H. N. Stokes, record No. 1514. 
A. Granulite (aplite), Yuba Gap, road east of Sierra Buttes. Tos- 
canose. Contains orthoclase, microcline, quartz, plagioclase, some 
shreds of greenish mica, and a little iron ore, chlorite, and apatite. 
P. R. C. 730. 
B. Granulite (aplite), dike east of Milton. Toscanose. Contains 
orthoclase, quartz, plagioclase, a little microcline, brown mica, and iron 
ore. P. R. C. 734. 
C. Biotite-quartz-monzonite, Indian Valley. Lassenose. Contains 
plagioclase, orthoclase, quartz, brown mica, apatite, and iron ore. 
P. R. C. 737. 
D. Quartz-diorite-porphyry, dike in Indian Valley granite. Yd- 
lowstonose. Contains plagioclase, hornblende, biotite, and quartz. 
P. R. C. 738. 
E. Quartz-mica-diorite, large area east of Milton. Harzose. Con- 
tains plagioclase, a turbid feldspar which is apparently not ortho- 
clase, quartz, green hornblende, brown mica, iron ore, and apatite. 
P. R. C. 732. 
Si0 2 
AlA 
FeA 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 at 100° . . . 
H 2 above 110 
Ti0 2 
PA 
MnO 
SrO 
BaO 
Li 2 
76.03 
13.39 
.48 
.31 
.05 
1.28 
2.98 
5.18 
.15 
.34 
.07 
.03 
trace 
trace 
.04 
none 
100. 33 
75.97 
13. 07 
.61 
.39 
. 14 
1.49 
2.51 
5.62 
.14 
.24 
.09 
trace 
trace 
.03 
.14 
trace 
100. 44 
c. 
J). 
68! 65 
66.65 
16. 34 
17. 61 
.93 
. 93 
1.48 
1.67 
1.29 
1.26 
3.07 
4.44 
4. 85 
4. 50 
1.85 
1.70 
.24 
.03 
.62 
.41 
.28 
.33 
.15 
.18 
.08 
.07 
.07 
.09 
.12 
trace 
trace 
99.99 
99.99 
E. 
57. 26 
16. 51 
3.27 
5.19 
:;.4i 
(>. 69 
2. 65 
2.93 
.20 
.95 
.53 
.30 
.18 
.06 
.10 
trace 
100. 23 
Bull. 228—04 15 
