CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
221 
F. Rhyolite, 3| miles southwest of Grizzly Peak. Toscanose. De- 
scription furnished by Turner. Contains sanidine, with less quartz 
and biotite, in a glassy groundmass. Analysis by Hillebrand, record 
No. 1461. P. R. C. 776. 
G. Hornblende-andesite, 4: miles from Pilot Peak. Tonalose. De- 
scribed by Turner in 14th Ann., p. 411. Contains plagioclase and 
hornblende in a groundmass carrying grains of magnetite. Analysis 
by Hillebrand, record No. 1432. " P. R. C. 716. 
H. Hornblende-pyroxene-andesite, southwest base of Mount Ingalls. 
Tonalose. Description supplied by Turner. Contains plagioclase, 
rhombic pyroxene, augite, brown hornblende, and magnetite, with 
much glass in the groundmass. Analysis by Hillebrand, record No. 
1456. P. R. C. 728. 
1. Hypersthene-andesite, Franklin Hill. Hessose. Description sup- 
plied by Turner. Contains plagioclase, rhombic pyroxene, augite, 
and magnetite. Probably no glass. Analysis by Hillebrand, record 
No. 1548. P. R. C. 754. 
Si0 2 .. 
A1A- 
Fe 2 :; . 
FeO.. 
MgO . 
CaO.. 
Na 2 0. 
K 2 0.. 
H 2 above 100° 
Ti0 2 
PA 
MnO 
SrO 
BaO 
71.39 
11. L3 
.63 
.37 
.08 
1.01 
2.89 
5.69 
.42 
3.32 
.17 
. 03 
trace 
trace 
.09 
trace 
100. 22 
60.20 
17.21 
3. 11' 
2.69 
:;. is 
6.04 
3.35 
1.44 
1.12 
1.18 
.57 
.17 
.12 
trace 
.11 
trace 
100. 50 
ii. 
58.47 
18.80 
8. 34 
2.64 
2.69 
6. 60 
3. 58 
2. 01 
.14 
.92 
.51 
. 22 
.13 
, .05 
.09 
trace 
100. 19 
56.88 
18.25 
2.35 
4.45 
4.07 
7.53 
3.29 
1.42 
.24 
.50 
.45 
.30 
.18 
.04 
.11 
trace 
100.06 
