CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
177 
The following rocks were also analyzed in the Denver laboratory, 
but the analyses are unpublished elsewhere. Petrographic data fur- 
nished by Whitman Cross. 
A. Granite-porphyry, NcNulty Gulch. Toscanose. Contains phe- 
nocrysts of orthoclase, oligoclase, andesine, quartz, biotite, and altered 
hornblende, in a gfroundmass of quartz, orthoclase, and magnetite. 
Accessoiw sphene, allanite, apatite, and zircon, and a little secondary 
chlorite are also present. Analysis by W. F. Hillebrand. P. R. C. 586. 
B. Granite-porphyry, Jefferson tunnel. Toscanose. Contains ortho- 
clase, oligoclase, quartz, and biotite, in a groundmass of mainly quartz 
and orthoclase; also accessory magnetite, apatite, zircon, and allanite. 
Chlorite appears as a decomposition product of biotite, and calcite and 
magnetite are present in small amounts. Analysis by Hillebrand. 
C. Same as B. Toscanose. Analysis by L. G. Eakins. P. R. C. 583. 
D. Diorite-porphyry, Copper Mountain. YeUowstonose. Contains 
oligoclase, hornblende, and biotite, in a groundmass of quartz, ortho- 
clase, plagioclase, and magnetite; also accessory zircon, sphene, and 
apatite, and a little secondary chlorite and epidote. Analysis by 
Eakins. P. R. C. 585. 
E. Diorite-porphyry, McNulty type. Lassenose. Contains oligo- 
clase, andesine, hornblende, biotite, and magnetite, in a groundmass 
of orthoclase, plagioclase, quartz, magnetite, apatite, allanite, and 
sphene; also secondary chlorite, epidote, and calcite. Analysis b} r 
Eakins. P. R. C. 584. 
Si0 2 . 
AlA 
Fe 2 3 
FeO. 
MgO 
CaO. 
Na,< ) 
K 2 () . 
H,(). 
P,0 5 
MnO 
Sr() . 
BaO. 
CO, . 
CI... 
S.... 
FeS 2 . 
Sp. gr 
68.60 
16. 21 
1.67 
1.57 
1.05 
2.61 
3.29 
3.88 
.92 
.21 
.09 
trace 
.19 
.03 
100. 32 
2. 640, 
65.94 
16.00 
.60 
1.74 
1.02 
2.87 
3.85 
4.56 
1.13 
.23 
.14 
trace 
1.55 
.03 
60 
100. 26 
2.672, 21° 
c. 
65.51 
17.01 
none 
2.79 
.90 
3.16 
3.82 
4.67 
1.78 
.13 
trace 
.38 
100. 15 
2.666, 26° 
i». 
67.01 
18.03 
.66 
.72 
.84 
3.99 
4.42 
3.53 
.91 
.10 
.09 
.10 
63. 02 
17.61 
1.78 
2.76 
1.63 
3. 30 
4.72 
3.23 
2.03 
.16 
trace 
08 
100.40 100.32 
2.689, L6.5° 
Bull. 228—04 12 
