IGNEOUS AND CRYSTALLINE ROCKS. 
209 
CALIFORNIA. 
1. MOUNT SHASTA. 
Description of rocks furnished by J. S. Diller, who also describes 
A, B, and C in Bull. 150, pp. 221, 227. 
A. Hornblende-andesite, Black Butte, west base of Shasta. Yellow- 
stonose. Contains plagioclase and hornblende in a microlitic ground- 
mass. The latter carries hypersthene, magnetite, and amorphous mat- 
ter. Analysis by W. H. Melville, record No. 1346. P. R. C. 84. 
B. Hypersthene-andesite, older now, west base of Shasta. Tellow- 
stonose. Contains plagioclase, hypersthene, magnetite, and glass. 
Analysis by Melville, No. 1346. P. R. C. 87. 
C. Hypersthene-andesite, like B, same locality, later now. Tonal- 
ose. Analysis by Melville, No. 1346. P. R. C. 87. 
D. Hornblende-andesite, late now, eastern side of Shasta. Tonalose. 
Contains small crystals of plagioclase and hornblende in a dark ground- 
mass. Thin section not examined. Analysis by H. N. Stokes, record 
No. 1532. 
E. Ophitic basalt from near the McCloud River, south of Mount 
Shasta, Hessose. A gray cellular rock. Thin section not examined. 
Analysis by Stokes, No. 1532. 
F. Andesite basalt, Delta, Shasta County. Beerbachose. Much 
plagioclase and a few hypersthene crystals in a groundmass chiefly of 
feldspar, pyroxene, magnetite, and trace of olivine. Analysis by 
Melville, No. 1346. 
A. 
B. 
c. 
I). 
E. 
F. 
Si 2 
64.48 
19.28 
1.40 
1.78 
1.64 
5.06 
4.41 
1.12 
| .06 
undet. 
64. 52 
18.31 
.90 
2.51 
2. 35 
5.11 
4. 64 
1.25 
| .20 
undet. 
63.03 
17.72 
2. 27 
1.92 
3.63 
5.97 
3.92 
1.06 
undet. 
61.58 
16. 96 
1.75 
2.85 
3.67 
6. 28 
3.94 
1.28 
.24 
1.06 
.49 
.22 
trace 
trace 
.03 
trace 
47.94 
18.90 
2.21 
8.59 
8.21 
9.86 
2.81 
.29 
.39 
.74 
.57 
.15 
trace 
none 
none 
trace 
55. 08 
A1 2 0, 
18. 93 
Fe 2 3 
2.02 
FeO 
5.56 
MgO 
5.17 
CaO 
8.40 
Na 2 
4.23 
K 2 0. 
.74 
H 2 Oat 110° 
| .29 
H 2 above 110° 
Ti0 2 
P 2 5 
trace 
MnO 
SrO 
BaO 
Li 2 
99.23 
99.79 
99.96 
100. 35 
100. 66 
100. 42 
Bull. 228—04 14 
