CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
117 
E. Butte granite, Gagnon mine, Butte. 
F. Butte granite, Atlantic mine, Butte. 
G. Butte granite, Alice mine, Butte. Analyses E, F, and G by 
W. H. Hillebrand, record No. 1692. Mineralogically the rocks are 
like A and D. 
H. Weathered Butte granite. 
1. Altered Butte granite. Decomposed near quartz-pyrite veins. 
Shows opaline silica, with sericite derived from feldspar. Hornblende 
gone; mica recognizable only as sericite masses having the form of 
biotite. 
Analyses H and I by Stokes, record Nos. 1792, 1787. 
Si0 2 .. 
ALA- 
Fe 2 3 
FeO.. 
MgO . 
CaO.. 
NaA 
K 2 0.. 
H 2 above 110° 
Ti0 2 
PA 
Zr0 2 
MnO 
NiO 
SrO 
BaO 
C0 2 
so, 
FeS 2 
Cu 
64.05 
15.38 
2.20 
2.74 
2.08 
4.30 
2.74 
4.00 
.27 
.83 
.60 
.21 
(?) 
.11 
trace ? 
.04 
.08 
.35 
07 
005 
100. 055 
64.34 
15.72 
1.62 
2.94 
2.17 
4.24 
2.76 
4.04 
.25 
.76 
.53 
.14 
.02 
.12 
trace ? 
.03 
.06 
.03 
.03 
.005 
99. 805 
G. 
63.87 
15.39 
1.93 
3.08 
2.23 
4.30 
2.76 
4.18 
.19 
.69 
.65 
.17 
.03 
.11 
trace 
.04 
.07 
.15 
.07 
.005 
99. 915 
n. 
65. 14 
15.63 
2.37 
2.13 
1.85 
3.62 
2.63 
4.29 
.37 
.75 
.59 
.16 
trace 
trace 
.10 
none 
.05 
99. 
64.81 
19.44 
1.82 
.16 
.19 
.18 
.21 
5.30 
1.41 
5.25 
.73 
.10 
trace 
trace 
.10 
none 
.31 
100. 01 
Traces of lithia in all five rocks of this table. 
