136 
ANALYSES OF ROCKS, IT. S. GEOLOGICAL SURVEY. [no. 228. 
F. Rhyolite, top of Red Mountain, Rimini. Liparose. Quartz and 
feldspar phenocrysts in a groundmass of the same minerals. 
G. Andesite-porphyry, Hiawatha Creek, above basin. Amiatose. 
Contains plagioclase, orthoclase, and augite. 
H. Andesite-porphyry, Zosel mining district, near Daylight. Near 
landose. Somewhat altered. Contains augite, andesine, and olivine 
in a groundmass of plagioclase, augite, and iron oxide. Ferromagne- 
sian minerals altered to serpentine. Analyses by H. N. Stokes, record 
Nos. 1686, 1787. 
Si0 2 . 
AlA 
Fe 2 3 
FeO . 
MgO 
CaO. 
Na 2 
H 2 Oatll0°_... 
H 2 above 110° 
Ti0 2 
PA 
Zr0 2 
MnO 
SrO 
BaO 
Li 2 
C0 2 
so 3 .-... 
FeS 2 
CI 
Cu 
Organic matter. 
75.30 
11.95 
2.17 
.05 
.62 
3.09 
4.96 
.36 
.61 
.17 
trace 
trace 
none 
trace 
trace 
none 
.44 
62. 53 
19.01 
1.96 
1.44 
1.29 
5.17 
3. 45 
3. 30 
.21 
.45 
.65 
.17 
.03 
.04 
.13 
trace 
none 
none 
n. 
54.61 
15. 23 
3.51 
4.80 
4.69 
7.41 
1.46 
2.70 
.32 
2.47 
.86 
.35 
none 
.09 
.04 
.11 
trace 
1.46 
none 
trace 
none 
45 
100.17 
99. 83 
100.11 
