262 ANALYSES OF ROCKS, IT. S. GEOLOGICAL SURVEY. [no. 228. 
Largely feldspar and pyrox- 
I. 5. S. 5. 
J. Basalt, Sawtooth Rock, 
ene, with some quartz. 
K. Dacite-porphyry, 6 miles west of Big- Bend of Rogue River. 
Kallerudose. Contains plagioclase and quartz, with some orthoelase, 
and scattered patches of chlorite and hornblende. 
L. Dacite-porphyry^ head of Boulder Creek. Yellowstonose. Con- 
tains abundant quartz, altered feldspar, grains of epidote, hornblende, 
and chlorite. 
M. Dacite-porphyry, south slope of Bald Mountain. Alsbachose- 
lasse mose. 
Si0 2 .. 
AUV 
Fe 2 3 - 
FeO.. 
MgO . 
CaO . . 
Na„0 . 
K 2 
H 2 0at 105°... 
H 2 above 105 c 
Ti0 2 
C() 2 
ZrG 2 
PA 
S 
FeS 2 .. 
MnO 
BaO . . 
SrO .. 
Cr 2 3 . 
NiO . 
53. 06 
12.83 
1.20 
5.10 
7.50 
13.71 
3. 56 
.05 
.16 
2.16 
.42 
.25 
trace? 
trace 
trace 
.16 
none 
none 
.06 
trace 
100. 22 
K. 
71.45 
14. 53 
.49 
.<>4 
.30 
2.01 
7.15 
2.55 
.15 
.38 
.16 
.08 
trace 
.09 
trace 
trace 
.03 
none 
100. 31 
L. 
70. 33 
15.74 
1.43 
.83 
.53 
3.38 
4. X\ 
1.87 
.20 
1.16 
.27 
trace 
none 
.06 
trace 
trace 
.09 
trace 
M. 
75.32 
13.17 
.27 
.98 
.42 
1.48 
4.77 
2.14 
.18 
.73 
.16 
.03 
none 
.04 
.09 
trace 
.23 
.02 
100.22 100.03 
