140 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [no. 228. 
R. Elseolite-syenite, Peaked Butte, northeast side of the mountains. 
Umptekose. Described by Wolff and Tarr, loc. cit. Contains anortho- 
clase, augite, occasionally sodalite, segirine, 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. Nord- 
marhose. 
U. Tinguaite, var. solvsbergite, dike at head of Sixteenmile Creek. 
Nordmarkose. 
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 bv W. H. Melville, record No. 1291. 
R. 
Ra. 
s. 
T. 
IT. 
Si0 2 
59. (>() 
16.97 
3.18 
1.15 
.80 
2.32 
8.38 
4.17 
.07 
2.53 
trace 
.14 
.19 
62. 31 
22. 63 
.63 
7.68 
4.79 
.16 
.72 
.57 
.77 
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 
ALO, 
17.52 
Fe 2 3 
3. 06 
FeO 
.94 
MgO 
.34 
CaO 
.56 
Na 2 
7.30 
K 2 , 
4.28 
H 2 at 1(1.")° 
.04 
H 2 above 105° 
.95 
Ti0 2 
trace 
P„0* 
trace 
MnO 
.35 
SrO 
BaO 
99. 56 
100. 26 
100. 00 
99. 50 
99.67 
V. Theralite, Gordons Butte. Malignose. Contains green augite, 
segirine, biotite, olivine, nephelite, sodalite, and a feldspar, partly sani- 
dine, containing K, Na, Ba, Sr, and Ca; also accessory apatite, magnet- 
ite, and sphene. 
W. Theralite, Gordons Butte; another sample. Kamerunose. Anal- 
ysis by E. A. Schneider, record No. 1281. P. R. C. 75. 
X. Theralite, north of Alabaugh Creek. Essexose. Described by 
Wolff for the Educational Series (Bull. 150). Contains augite, aagirine, 
biotite, olivine, magnetite, apatite, nephelite partly zeolitized, a mineral 
of the sodalite group, sanidine, and analcite. Analysis by Schneider, 
No. 1281. P. R. C. 76. 
