200 
AJNALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
3. MORENCI DISTRICT. 
Rocks collected by Waldemar Lindgren, but as yet undescribed. 
Analyses by W. F. Hillebrand, record No. 1997. 
A. Fresh porphyry, Ryerson mine, 100-foot level. Lassenose. 
P>. Altered porphyry, same locality as A. 
( ). Altered porphyry, chalcocite zone, Humboldt stopes. 
I). Surface alteration of altered porphyry, Copper Mountain. 
E. Primary silicification of porphyry, Ryerson mine. 
SiO. 
ALA-- 
Fe 2 3 .. 
FeO 
MgO 
CaO . 1 
Na 2 
K 2 
H 2 at 105° _ . _ 
H 2 above L05' 
Ti0 2 
Zr0 2 
P,0, 
S( ) ;; . 
MnO 
BaO. 
SrO . 
Li,( ) . 
V 2 < >, 
FeS 2 . 
Cu 2 S 
ZnS . 
MoS, 
68.04 
17.20 
.34 
.67 
1.05 
2.21 
2. 65 
.60 
1.23 
.11 
.01 
. 12 
.06 
.10 
.03 
trace 
trace 
.24 
.02 
.03 
none 
100.34 
B. 
46.67 
20.92 
.37 
.36 
.85 
.15 
.16 
4.33 
.94 
5.01 
.43 
trace 
.15 
.18 
none 
.04 
none 
trace 
100.50 
64. 88 
16. 41 
.65 
1.12 
.11 
.12 
4.96 
.83 
2.74 
.38 
trace 
.12 
.10 
trace? 
.07 
trace? 
trace 
19.18 
4.96 
.24 
2.42 
.32? 
none 
.20 
none 
99.87 
D. 
72.78 
15. 35 
.55 
.10 
.89 
.14 
.36 
5.00 
1.21 
3.22 
.45 
trace 
.05 
.08 
none 
.02 
none 
trace 
06 
100. 26 
69.55 I 
16. 43 
.46 
.11 
.62 
.15 
.17 
5. 05 
1.00 
2.69 
.41 
trace 
.05 
.10 
none 
.05 
none 
trace? 
3.09 
.07 
none 
100.00 
