IGNEOUS AND CRYSTALLINE ROCKS. 119 
C. Andesite, Tintic Mountain. Harzose. Phenocrysts of biotite and feldspar. 
Contains plagioclase, chiefly labradorite, augite, biotite, hypersthene, magnetite, and 
apatite, in a dark-gray glass. P. R. C. 1036. 
D. Granular monzonite, Iron Duke mine. Harzose. Contains orthoclase, plagio- 
clase, quartz, hornblende, biotite, magnetite, apatite, zircon, and titanite, with a 
little chlorite and epidote. P. R. C. 1032. 
E. Altered monzonite, near Tintic mine. Feldspar and ferromagnesian minerals 
completely altered. Rutile is present: quartz seems to have been added. 
H20 above Tr aan ons akan aloe tana Degli ed apne ees 
Ti 
Fluorine was not looked for in the analyses. 
2. ROCKS FROM HENRY MOUNTAINS. 
A. Porphyry. Tonalose. Not hitherto published. Reported by J. 8S. Diller as 
containing prominent plagioclase with some augite and hornblende in a crystalline 
groundmass of quartz and orthoclase. Analysis by R. B. Riggs, record No. 728. 
B. Augite porphyrite, dike, north spur of Mount Pennell. Laurvikose. Contains 
hornblende, augite, and plagioclase in a feldspathic groundmass. 
C. Hornblende porphyrite, Mount Hillers. Tonalose. Contains plagioclase, 
hornblende, quartz, and magnetite. 
Analyses B and C by W. F. Hillebrand, record No. 1428. Rocks described by Cross 
in 14th Ann., p. 165. 
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