IGNEOUS AND CRYSTALLINE ROCKS. "5 
F. Augite porphyry, Cottonwood Creek. Shoshonose. Contains feldspars, augite, 
and brown mica, with iron oxides, apatite, glass, and secondary calcite and chlorite. 
Carries porphyritic plagioclase and augite. No unaltered olivine visible. Sp. gr., 
2.785. Analysis by Eakins, record No. 819. P. R. C. 965. 
G. Basalt (?), Bear Creek. Lamarose. Resembles A, but with a more crystalline 
groundmass. Contains plagioclase, possibly sanidine, augite, olivine, and iron oxides. 
Analysis by Chatard, record No. 1154. P. R. C. 967. 
H. Lamprophyre, between South Boulder and Antelope creeks. Kentallenose. 
Contains porphyritic augite and olivine in a feldspathic groundmass, with apatite, 
augite, grains of iron oxide, and shreds of brown mica. Sp. gr., 2.96. Analysis by 
Eakins, record No. 1266. P.R. C. 966. 
I. Lamprophyre, hills east of South Boulder Creek. Near auvergnose. Nodules 
from a decomposed mass. Shows sanidine, plagioclase, brown mica, and altered 
olivine. 
s 
wr 
B82 3 RSESr8aS 
a 
S NPNSONS 
2 
HaO at 110°... . 
HO above 110° 
TiO 
J. Hornblende picrite, North Meadow Creek. Wehrlose. Contains hornblende, 
abundant fresh olivine, grains of pleonaste and iron oxides, and occasionally hyper- 
sthene. Sp. gr., 3.35. P. R. C. 973. 
K. Pyroxenite, divide between Meadow and Granite creeks. Cookose. Contains 
hornblende and hypersthene, with grains of iron oxide. P. R. C. 972. 
