110 ANALYSES OF ROCKS AND MINERALS, 1880-1908. 
2 
H20 at 110°... 
20 above 110°.. 
The following rocks were also analyzed in the Denver laboratory. Petrographic 
data furnished by Whitman Cross. 
A. Granite porphyry, McNulty Gulch. Toscanose. Contains phenocrysts of 
orthoclase, oligoclase, andesine, quartz, biotite, and altered hornblende, in a ground- 
mass of quartz, orthoclase, and magnetite. Accessory 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 orthoclase, oligo- 
clase, quartz, and biotite, in a groundmass of mainly quartz and orthoclase; also 
accessory magnetite, apatite, zircon, and allanite. Chlorite appears as a decompo- 
sition product of biotite, and calcite and magnetite are present in small amounts. 
Analysis by Hillebrand. 
C. Sameas B. Toscanose. Analysis by L. G. Eakins. P. R. C. 583. 
D. Diorite porphyry, Copper Mountain. Yellowstonose. Contains oligoclase, horn- 
blende, and biotite, in a groundmass of quartz, orthoclase, plagioclase, and mag- 
netite; also accessory zircon, sphene, and apatite, and a little secondary chlorite and 
epidote. Analysis by Eakins. P. R. (. 585. 
E. Diorite porphyry, McNulty type. Lassenose. Contains oligoclase, andesine, 
hornblende, biotite, and magnetite, in a groundmass of orthoclase, plagioclase, quartz, 
magnetite, apatite, allanite, and sphene; also secondary chlorite, epidote, and calcite. 
Analysis by Eakins. P. R. C. 584. 
100. 32 100. 26 100.15 | 100. 40 
Ds Bliss ost: seg aennee hr Maan teense 2.640, 27° | 2.672, 21° | 2.666, 26° 
100. 32 
a aateningigie 2. 689, 16. 5° 
