112 
ANALYSES OF KOCKS, U. S. GEOLOGICAL SURVEY. [no. 228. 
3. ISHAWOOA INTRUSIVES. 
Descriptions, hitherto unpublished, supplied by Arnold Hague and 
T. A. Jaggar, jr. Analyses A and B by H. N. Stokes, record No. 
1804; C and D by W. F. Hillebrand, No. 1765. 
A. Granite-porphyry, base of Crater Mountain. Yellowstoriose. 
Contains oligoclase, orthoclase, biotite, and quartz. 
B. Diorite-porphyry, Cabin Creek. Tonalose. Contains plagioclase, 
orthoclase, quartz, and abundant hornblende. This rock is inter- 
mediate between granite-porphyry and diorite-pophyry, but nearer to 
the latter. 
C. Diorite, base of Needle Mountain. Yellowstonose. Contains 
plagioclase, quartz, biotite, with subordinate hornblende and ortho- 
clase. Structure granitic. 
D. Diabase, entrance to Shoshone Canyon. Andose. Contains 
plagioclase, augite, and chlorite. 
Si0 2 .. 
ALA- 
Fe 2 3 
FeO.. 
MgO. 
CaO.. 
Na 2 0. 
K,0.. 
H 2 above 110° 
Ti0 2 
PA - 
NiO 
MnO 
SrO 
BaO 
Li 2 
C0 2 
CI 
s 
FeS, 
A. 
64.23 
16.34 
1.07 
1.58 
2.47 
3.07 
3. 49 
2. 59 
.47 
1.76 
.50 
. IS 
none 
trace 
. 06 
.19 
trace 
.30 
1.61 
99.91 
60.00 
16. 37 
2.28 
2.46 
3.81 
4.96 
3.73 
2.70 
.61 
1.42 
.59 
. 35 
none 
.05 
.11 
.26 
trace 
.17 
63. 76 
16.01 
2.22 
1.96 
2.43 
4.55 
3.98 
2.84 
.28 
.57 
.52 
.25 
none 
.09 
.09 
17 
trace 
.23 
trace 
(?) 
99. 87 99. 95 
52.18 
18.19 
3. 31 
4.36 
4.69 
6.51 
4.58 
1.88 
.75 
2.00 
.99 
.29 
trace 
.14 
.06 
.11 
trace 
none 
trace 
none 
100. 04 
