254 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [no. 228. 
N. Scoriaceous rhyolite, Mono Craters, south of Mono Lake. 
Liparose. Described by Russell in 8th Ann., Part I, p. 380. Analy- 
sis by T. M. Chatard, record No. 36. 
O. Obsidian, Mono Lake. Liparose. Analysis by W. H. Melville, 
record" No. 1346. Described by Lindgren in Bull. 150, p. 149. P. 
R. C. 60. 
P. Pumice, Mono Lake. Toscmiose. Analysis by Melville, No. 
1346. Described by Lindgren in Bull. 150, p. 148. P. R. C. 59. 
Q. Volcanic ash, east shore of Owens Lake. Collected and analyzed 
by Chatard, record No. 783. 
N. 
0. 
p. 
Q. 
Si0 2 
74. 05 
13. 85 
trace 
75.78 
12.39 
.22 
1.25 
.31 
.81 
4.00 
4.64 
} ■« 
67.39 
15. 99 
.56 
1.99 
.77 
1.63 
4.74 
4.80 
| 2. 06 
55. 81 
ALOo 
10.07 
FeoOo 
3.43 
FeO 
.67 
MffO 
.07 
.90 
4.60 
4.31 
1 2.20 
2.22 
CaO 
1.05 
Na 2 - 
.75 
K 2 
2.98 
H 2 at 110° 
.65 
H 2 above 110° 
2.50 
Ti0 2 
.80 
P.O. 
.27 
MnO 
.23 
CaC0 3 
14.44 
NaCl, soluble 
1.45 
Na 2 S0 4 , soluble 
.80 
Na 2 CO<$, soluble 
2.09 
99.98 
99.81 
99.93 
100. 21 
