114 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[BULL. 168. 
J. Hornblende-picrite, North Meadow Creek. Contains hornblende, 
abundant fresh olivine, grains of pleonaste and iron oxides, and occa- 
sionally hypersthene. Sp. gr. 3.35. P. R. C. 973. 
K. Pyroxenite, divide between Meadow and Granite creeks. Con- 
tains hornblende and hypersthene, with grains of iron oxide. P. R. C. 
972. 
L. Hypersthene-andesite, northwest of Red Bluff. Contains plagio- 
clase and pyroxene, with an amorphous glassy base, and sometimes 
olivine altered to chloritic matter. 
M. Peridotite, var. wehrlite, hills 3 miles northwest of Red Bluff. 
Contains olivine, diallage, brown mica, rarely plagioclase, and second- 
ary iron oxides. Sp. gr. 3.37. Analyses J, K, L, and M by Eakins, 
record No. 1266. P. R. C. 976. 
J. 
K. 
L. 
M. 
Si0 2 
A1 2 3 
46. 13 
4.69 
.73 
16.87 
25.17 
4.41 
.08 
trace 
1.38 
.73 
.07 
.04 
trace 
.09 
trace 
.24 
51.83 
7.98 
1.48 
8.28 
24.10 
5.26 
.35 
.06 
.29 
.29 
.09 
.31 
trace 
.11 
59.48 
16.37 
3.21 
3.17 
3.29 
4.88 
3.30 
2.81 
2.01 
.93 
.41 
.03 
.19 
trace 
.13 
48.95 
5.69 
1.20 
12.11 
23.49 
5.33 
1.58 
.79 
.18 
.81 
.12 
.05 
.08 
.16 
trace 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 
Ti0 2 
P 2 5 
Cr 2 3 
MnO 
NiO 
BaO 
S 
Less 
100. 63 
.12 
100. 43 
100. 21 
100. 54 
100.51 
