IGNEOUS AND CRYSTALLINE ROCKS. 175 
H20 at 110°... 
H20 above 110°. 
2. COPPER RIVER BASIN. 
Andesites, described in P. P.41. Analyses A, B, by W. F. Hillebrand, record No. 
2075. C, D, by George Steiger, record No. 2080. 
A. Dark, vesicular, porphyritic lava, late eruption, Mount Wrangell. Tonalose. 
Contains labradorite, hypersthene, olivine, and magnetite in a brown glassy base. 
Collected by W. C. Mendenhall. 
B. Gray, porphyritic, well-crystallized older lava, Mount Drum. Tonalose. Con- 
tains plagioclase, hornblende, biotite, hypersthene, magnetite, apatite, and zircon 
in a fine gray hypocrystalline base. Collected by W. C. Mendenhall. 
C. Augite andesite, lower north slope of Mount Sanford. Kadlerudose. Contains 
plagioclase, augite, and magnetite in a microcrystalline groundmass of the same min- 
erals. Collected by F. C. Schrader. 
D. Hypersthene andesite from near C. Lassenose. Contains plagioclase, horn- 
blende, hypersthene, and magnetite in a glassy groundmass of mainly plagioclase and 
hypersthene. Collected by F. (. Schrader. 
22 23 .09 08 
36 1.01 45 51 
73 48 .30 51 
01 01 05 05 
18 15 -10 27 
02 01 | none none 
14 ll +15 16 
05 06 06 03 
02 03 | trace trace 
100. 29 | 100.35 | 100.45 | 100.16 
COz and S absent. 
