IGNEOUS AND CRYSTALLINE ROCKS. 105 
B. Augite diorite, Mount Fairview, Rosita Hills. Salemose. Contains ausile. 
biotite, labradorite, and accessory orthoclase, olivine, magnetite, and apatite. Sp. 
gr., 2.870, 32°. Olivine a subordinate consituent. P. R. (. 526. 
C. The same as B, but with orthoclase in much larger amount. Akerose. Sp. 
gr., 2.768, 34° Record No. 1091. P. R. (. 529. 
D. Trachyte, Game Ridge. Phlegrose. Contains sanidine, plagioclase, a little 
biotite, magnetite, apatite, and zircon in a groundmass of orthoclase, with a little 
quartz. Sp. gr., 2.592, 29°. P. R.C. 70 and 524. 
E. Trachyte, dark-colored dike. Pulaskose. Contains more magnetite than D, 
but otherwise the two are practically identical. Sp. gr., 2.621, 24° P. R. C. 589. 
F. Andesite, Pringle Hill. Pulaskose. Contains plagioclase, orthoclase, quartz, 
biotite, augite, magnetite, and apatite, with sometimes a little hornblende. Sp. gr., 
2.651, 17.8°. Record No. 1124. P. R. C. 528. 
G. Pringle andesite, dike. Laurvikose. Like F, but often contains sphene. Sp. 
gr., 2.690, 28°. P.R. C. 527. ; 
H. Bunker andesite, Lookout Mountain. <Akerose. Contains plagioclase, ortho- 
clase, augite, biotite, hornblende, quartz, magnetite, and apatite. Sp. gr., 2.699, 
34°. Record No. 1091. 
I. Altered Bunker andesite, Robinson Plateau. Toscanose. Biotite gone, mag- 
netite altered to limonite, feldspars not much attacked. Record No. 1124. Sp. gr., 
2.580, 19.7° 
J. Much-decomposed Bunker andesite, ridge near Knickerbocker Hill. Liparose. 
Augite, hornblende, and biotite all replaced by decomposition products, plagioclase 
much muscovitized. Record No. 1124. P. R. C. 592. 
3. 69 2.21 45 
2. 36 .57 -07 
2. 34 58 ~44 
4,29 2. 03 -55 
4,95 4.19 4.17 
3.72 3. 88 5.28 
2.29 2. 63 2.98 
w2e leg weapon 30 
BO Ns hs trace 
21 | trace trace 
