CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
99 
WYOMING. 
Rocks A to J, inclusive, studied by Whitman Cross. The Leucite 
Hills series is described in Amer. Jour. Sci., 4th ser., vol. 4, p. L15. 
Analysis J is b}^ L. G. Eakins, record No. 1078. The others are by 
W. F. Hillebrand, one made in the Denver laboratory, and record Nos. 
343, 355, 362, 368, 403, 463, 1668, and 1682. 
A. Wyomingite, Boars Tusk, Leucite Hills. Wyomingose. Con- 
tains phlogopite, leucite, diopside, and apatite. Sp. gr., 2.779, 13.5°. 
P. R. C. 567. 
B. Wyomingite, Fifteenmile Spring, Leucite Hills. Orendose. 
Composition like A. Sp. gr., 2.627, 30°. P. R. C. 566. 
C. Portion of B soluble in 2.5 per cent nitric acid. 
D. Phlogopite from.wyomingite. 
E. Madupite, Pilot Butte, Leucite Hills. Madupose. Contains 
predominating diopside and phlogopite, with perofskite and magnetite, 
in a glassy base which has approximately the composition of leucite. 
Sp. gr., 2.857, 22°. P. R. C. 576. 
p.. 
D. 
]•:. 
Si0 2 
A1A 
FeA 
FeO 
MgO 
CaO 
Na 2 
K 2 
iH 2 OatllO°. 
H 2 above 1 
Ti0 2 
PA 
3r 2 ;i 
Di 2 3 , etc. «. 
MnO 
M) 
BaO 
U 2 o 
A---:---. 
:i 
50.23 
11.22 
3.34 
1.84 
7.09 
5.99 
1.37 
9.81 
.93 
1.72 
2.27 
1.89 
.10 
.03 
.05 
.24 
1.23 
trace 
.74 
.03 
.50 
53.70 
11.16 
3.10 
1.21 
6.44 
3.46 
1.67 
11.16 
.80 
2.61 
1.92 
1.75 
.04 
none 
.04 
.19 
.62 
trace 
.06 
.03 
.44 
100. 62 
.22 
100. 40 
.19 
100.40 100.21 
,76 
.91 
.50 
1.51 
2.13 
.28 
1.21 
(?) 
(?) 
.21 
1.54 
42. 56 
12.18 
2.73 
.90 
22.40 
.20 
.44 
10.70 
2.35 
2.09 
.06 
. ::; 
trace 
1.00 
trace 
2.46 
14.70 
100. 80 
1.03 
99. 77 
42.65 
9.14 
5.13 
1.07 
10.89 
12.36 
.90 
7. 99 
2.04 
2.18 
1.64 
1.52 
.07 
.11 
.12 
.33 
.89 
trace 
.58 
.03 
.47 
loo. U 
.20 
90.91 
« Probably contains other rare earths. 
