IGNEOUS AND CRYSTALLINE ROCKS. ~ 61 
F. Quartz-mica diorite. Tonalose. Contains biotite, hornblende, augite, hyper- 
sthene, plagioclase, orthoclase, and quartz. Analysis by Whitfield, No. 921. 
G. Quartz-mica diorite. Yellowstonose. Contains biotite, hornblende, plagioclase, 
pyroxene, quartz, and orthoclase. Analysis by Whitfield, No. 921. 
H, I, J. Quartz-mica diorites. Yellowstonose. Contain hornblende, _ biotite, 
plagioclase, orthoclase, and quartz. Analyses by Whitfield, Nos. 921 and 830. 
F. a. Tl. I. J. 
K. Quartz-mica diorite porphyry. Yellowstonose. Contains biotite, hornblende, 
plagioclase, orthoclase, and quartz. Analysis by Whitfield, No. 830. 
L. Quartz-mica diorite porphyry. Lassenose. Contains quartz, biotite, plagioclase, 
alkali feldspar, and hornblende. Analysis by Whitfield, No. 830. 
M. Hornblende porphyry. Tonalose. Intrusive sheet. Contains hornblende, 
plagioclase, magnetite, and quartz. Analysis by Whitfield, No. 429. 
N. Hornblende-mica porphyry. Yellowstonose. Intrusive sheet. Contains horn- 
blende, plagioclase, biotite, magnetite, and quartz. Analysis by Whitfield, No. 420. 
The Indian Creek laccolith. 
O. Augite andesite porphyry. Monzonose. Intrusive sheet, upper portion. Con- 
tains malacolite, plagioclase, probably orthoclase, magnetite, and little biotite, with 
secondary chlorite or serpentine and actinolite. Analysis by Whitfield, No. 830. 
P. Same sheet as O, lower portion. Kentallenose. Analysis by W. F. Hillebrand, 
record No. 1571. 
K. i, M. N (0) P 
STL Oy ee ene ea eee Cute So RE ee eee 69.24 | 58.49] 61.50] 5210] 50.59 
AlsOa 15.30] 16.70] 17.42] 16.34] 11.49 
Fe,03 1.72] 3.85] 466] 3.84] 1.83 
FeO. -69| 2.37] 109} 682] 7.64 
MgO -95] 3.12} 126] 4.33] 11.97 
CaO. 298] 5.90) 5.33) 473] 8.79 
NazO 4.46] 3.47] 3.99] 402] 2097 
Oe eefnbiednies eaneer ANet ae uence 6 clad 2.52, 159) 129] 420] 233 
Ke 
HO at 110°..-. 
Ho above 110? 2: teacssesseains ne tareceeasereedara 
TiO. 
