:larke.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
123 
R. Elaeolite-syenite, Peaked Butte, northeast side of the mountains. 
Described by Wolff and Tarr, I. c. Contains anorthoclase, augite, 
occasionally sodalite, a3girine, apatite, magnetite, and some interstitial 
nephelite. Analysis by W. H. Melville, record No. 1291. 
Ra. Anorthoclase from R. Analysis by W. F. Hillebrand, record 
No. 1297. 
S. Tinguaite, var. solvsbergite, intrusive sheet north of Shields 
River. 
T. Tinguaite, var. solvsbergite, dike north part of mountains. 
U. Tinguaite, var. solvsbergite, dike at head of Sixteenmile Creek. 
S, T, and U are the rocks described by Wolff and Tarr in their 
paper upon "Acmite-Trachyte." Mineral composition the same as 
under R. Analyses by W. H. Melville, record No. 1291. 
R. 
Ra. 
s. 
T. 
u. 
Si0 2 
59.66 
16.97 
3.18 
1.15 
.80 
2.32 
8.38 
4.17 
.07 
2.53 
trace 
.14 
.19 
62.31 
22.63 
58.70 
19.26 
3.37 
.58 
.76 
1.41 
8.55 
4.53 
.07 
2.57 
trace 
.10 
.10 
62.17 
18.58 
2.15 
1.05 
.73 
1.57 
7.56 
3.88 
.07 
1.63 
trace 
.11 
trace 
64.33 
17.52 
3.06 
.94 
.34 
.56 
7.30 
4.28 
.04 
.95 
trace 
trace 
.35 
A1 2 3 
Fe 2 3 
FeO 
MgO 
CaO 
.63 
7.68 
4.79 
.16 
.72 
Na 2 
K 2 
H 2 at 105° 
H 2 above 105° 
Ti0 2 
P 2 5 
MnO 
SrO 
.57 
.77 
BaO 
99.67 
99.56 
100. 26 
100. 00 
99.50 
V. Theralite, Gordons Butte. Contains green augite, asgirine, bio- 
tite, olivine, nephelite, sodalite, and a feldspar, partly sanidine, con- 
taining K, Na, Ba, Sr, and Ca; also accessory apatite, magnetite, and 
sphene. 
W. Theralite, Gordons Butte; another sample. Analysis by E. A. 
Schneider, record No. 1281. 
X. Theralite, north of Alabaugh Creek. Descrided by Wolff for 
the Educational Series. Contains augite, aegirine, biotite, olivine, mag- 
netite, apatite, nephelite partly zeolitized, a mineral of the sodalite 
group, sanidine, and analcite. Analysis by Schneider, No. 1281. 
Rocks V, W, and X are described by Wolff in Bull. 150, pp. 197, 199. 
