CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
103 
YELLOWSTONE NATIONAL PARK AND THE ABSAROKA RANGE. 
1. ELECTRIC PEAK. 
Rocks described by Iddings in 12th Ann. , p. 577. Also in Bull. Phil. 
Soc. Washing-ton, vol. 11, p. 2(H). For analyses O, P, see Mon. XXXII, 
Pt. II. 
A. Pyroxene-mica-diorite. Tonalose. Contains augite, hyper- 
sthene, plagioclase, quartz, biotite, hornblende, magnetite, and apatite. 
Analysis by J. E. Whitfield, record No. 830. P. R. C. 94. 
B. Pyroxene-mica-diorite. Andose. Same minerals as under A. 
Analysis by Whitfield, No. 921. 
C. Pyroxene-mica-diorite. Tonalose. Like A and B. Analysis by 
W. H. Melville, record No. 1231. 
D. Pyroxene-porphyry. Andose. Contains augite, hypersthene, 
biotite, magnetite, plagioclase, and quartz. Analysis by Whitfield, 
No. 830. 
E. Quartz- pyroxene-mica-diorite. Tonalose. Contains biotite, horn- 
blende, augite, hypersthene, magnetite, plagioclase, orthoclase, and 
quartz. Analysis by Melville, No. 1231. 
Si0 2 
A1A 
FeA 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 Oatl00°. 
Ti0 2 . 
j?A- 
MnO 
NiO. 
Li 2 0. 
po 3 .. 
Cl... 
A. 
56. 
14. 
4. 
4. 
6. 
7. 
2. 
1. 
28 
23 
69 
05 
37 
94 
98 
23 
93 
84 
40 
Hi 
.01 
trace 
.17 
100. 28 
58. 05 
18.00 
2.49 
4.56 
3. 55 
6.17 
3.64 
2.18 
.86 
1.05 
.17 
none 
C. 
none 
.07 
trace 
100. 79 
61.22 
16.14 
3.01 
2.58 
4.21 
5.46 
4.48 
1.87 
.04 
.40 
.61 
.25 
trace 
.09 
100. 36 
57.38 
16.86 
2.49 
5.17 
5.51 
7.32 
3. 33 
1.45 
.42 
trace 
trace 
trace 
.39 
.21 
.17 
100. 70 
64. 07 
15.82 
3. 40 
1.44 
3. 39 
4.43 
4.06 
2.27 
.10 
.42 
.45 
.18 
trace 
.05 
100. 08 
