186 
ANALYSES OF KOCKS, U. S. GEOLOGICAL SURVEY. 
[BULL. 
K. Recent basalt, Pit River. Rich in feldspar and augite, poor in 
olivine. Partial analysis by F. W. Clarke, record No. 109. 
L. Basalt, 1 mile southeast of Paynes Creek, on the road from Red 
Bluff to Lassen Peak. A normal basalt, rather rich in olivine. Analy- 
sis by T. M. Chatard, record No. 405. 
M.* Basalt, summit of Inskip Crater, 25 miles east of Red Bluff. 
Mainly feldspar and augite, with a few phenocrysts of olivine. Analy- 
sis by Hillebrand and Chatard, record No. 406. 
N. Basal t from the cone at south base of Burney Butte, Shasta County. 
Composed of plagioclase and augite, with some olivine and a globulitic 
base. Analysis by R. B. Riggs, record No. 685. 
O. Basalt, near eastern end of rim of Crater Peak, Shasta County. 
Contains plagioclase and pyroxene, some of the latter being hyper- 
sthene with a trace of olivine. Analysis by R. B. Riggs, record No. 682. 
P. Hornblende-basalt, Kosk Creek, near its mouth, by the great bend 
of Pit River, Shasta County. Contains abundant phenocrysts of horn- 
blende, with a few of plagioclase, pyroxene, and olivine, in a ground- 
mass of plagioclase, augite, and magnetite. The hornblendes are 
deeply corroded, and some have disappeared, leaving groups of magne- 
tite grains to mark their former presence. Analysis by L. G. Eakins, 
record No. 1022. Described by Diller in Arner. Geologist, vol. 19, p. 
253. 
Rocks dried at 105° to 110° before analysis, except in the case of the 
rock marked L. 
K. 
L. 
M. 
N. 
0. 
P. 
Si0 2 
AlA 
Fe 2 3 ---- 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 
Ti0 2 
51.92 
19.76 
| 11.21 
3.38 
9.30 
2.16 
.60 
1.54 
47.93 
18.51 
2.07 
7.25 
9.03 
11.14 
2.28 
.24 
.76 
.73 
.11 
.20 
50.89 
16.76 
3.86 
4.69 
8.49 
11.72 
2.61 
.32 
.41 
.79 
.09 
.13 
52.63 
17.62 
6.49 
3.10 
5.64 
8.62 
3.38 
1.73 
.79 
.07 
.47 
trace 
trace 
.04 
trace 
52.95 
18.25 
4.36 
4.19 
4.93 
8.73 
3.57 
.77 
1.47 
.66 
trace 
.12 
trace 
.01 
(?) 
44.77 
17.82 
5.05 
6.95 
8.22 
10.36 
2.13 
.92 
2.64 
.53 
.72 
trace 
PA 
MnO 
SrO 
BaO 
trace 
Li 2 
C0 2 
none 
S0 3 
trace 
trace 
99.87 
100. 25 
100. 76 
100. 58 
100. 01 
100. 11 
