80° ANALYSES OF ROCKS AND MINERALS, 1880—1908. Mii 
F. Rhyolite, top of Red Mountain, Rimini. Liparose. Quartz and feldspar pheno- 
crysts in a groundmass of the same minerals. 
G. Andesite porphyry, Hiawatha Creek, above basin. -Amiatose. Contains plagio- 
clase, orthoclase, and augite. 
H. Andesite porphyry, Zosel mining district, near Daylight. Near bandose. Some- 
what altered. Contains augite, andesine, and olivine in a groundmass of plagioclase, 
augite, and iron oxide. Ferromagnesian minerals altered to serpentine. Analyses by 
H. N. Stokes, record Nos. 1686, 1787. 
| 
2 
ss] 
mon 
S, VEN aE woe 
RESSSEESSARE 
4. CRAZY MOUNTAINS. 
The greater number of the rocks in this group were received from J. E. Wolff, who has 
supplied the petrographic data. The few exceptions are properly indicated. The 
three tinguaites and the eleolite syenite were described by Wolff and Tarr in Bull. 
Mus. Comp. Zool., vol. 16, No. 12, 1893, in a paper upon ‘‘Acmite-Trachyte from the 
Crazy Mountains.’’ The renaming of these rocks is due to Wolff. The analyses, ex- 
cept when otherwise stated, are by W.-F. Hillebrand, record No. 1438. ‘ 
A. Granitite, Big Timber Creek. Toscanose. Small dikes in main diorite stock. 
Contains quartz, orthoclase, plagioclase (oligoclase), and biotite. P.R. C. 1720. 
B. Hornblende granitite, main stock, Big Timber Creek. Dacose. Contains biotite, 
hornblende, quartz, orthoclase, and plagioclase (oligoclase). P. R. C. 1721. 
C. Granite porphyry, intrusive sheet, north part of the mountains. Lassenose. 
Contains orthoclase, albite, quartz, biotite, and green hornblende in a groundmass of 
quartz and untwinned feldspar. P.R. C. 1722. 
D. Porphyrite, intrusive sheet, Sweet Grass Creek. Lassenose. Contains horn- 
blende and andesine in a groundmass of plagioclase, orthoclase, and quartz, with ac- 
cessory magnetite. P. R. C. 1723. 
E. Porphyrite, dike in contact zone, Sweet Grass Creek. Toscanose. Contains 
brown hornblende, biotite, and labradorite in a groundmass of plagioclase, biotite, and 
hornblende, with a little quartz and orthoclase. P. R. C. 1724. 
F. Porphyrite, intrusive sheet, middle peak of Three Peaks. Akerose. Contains 
andesine, hornblende, augite, and biotite in a groundmass of plagioclase, orthoclase, 
and quartz. P.R.C. 1725. 
