58 
IRON ORES OF IRON SPRINGS DISTRICT, UTAH. 
Analyst's of igneous rocks from Iron Springs district. 
CHEMICAL COMPOSITION. 
A. 
B. 
C. 
D. 
E. 
E'. 
F. 
G. 
Si0 2 . 
65. 29 
11.57 
2.10 
2.67 
2.87 
4.85 
2.10 
5.18 
2.32 
.22 
63.63 
15.64 
3.59 
.93 
2.32 
4.46 
1.70 
5.22 
2.10 
.15 
64.83 
16.68 
3.74 
1.22 
.79 
2.85 
.86 
7.56 
.92 
.35 
58.04 
18.96 
5.88 
1.33 
1.11 
6.12 
2.26 
4.08 
2.05 
.34 
66.38 
13.72 
2.23 
.80 
.54 
5.49 
2.50 
5.20 
.92 
.08 
2.52 
.11 
70.03 
14.47 
2.35 
.84 
.57 
s 2.42 
2.64 
5.48 
.97 
.08 
73.17 
13. 34 
1.35 
.76 
.81 
1.32 
1.80 
7.10 
.54 
.07 
61.05 
AI2O3 
16.03 
Fe 2 Oi... 
5.42 
FeO 
.98 
MgO 
3.03 
CaO 
5.40 
Na 2 
1.43 
K 2 
5. 58 
H 2 0+.. 
.81 
P2O5... 
.30 
C0 2 
BaO 
.17 
.05 
.11 
.04 
.11- 
.10 
.08 
99.34 
99.79 
99. 91 
100. 21 
100. 49 
99. 96 
100.36 
100. 11 
MINERAL COMPOSITION DETERMINED FROM THIN SECTIONS. 
A. 
B. 
('. 
D. 
E. 
F. 
G. 
Some . . . 
Some. .. 
Much . . . 
Some. .. 
Some . . . 
Little... 
Little... 
Some . . . 
Much . . . 
Much 
Little... 
Some . . . 
Some. .. 
Some . . . 
Little... 
Some. .. 
Some . . . 
Much.. . 
Some. .. 
Little... 
Some . . . 
Little... 
Little... 
Some . . . 
Much 
Little... 
Some. 
Little... 
Little... 
Little... 
Little... 
Little... 
Little... 
Little... 
Little. 
MINKRAL COMPOSITION CALCULATED FROM CHEMICAL COMPOSITION. 
A. 
B. 
C. 
D. 
E. 
F. 
G. 
Quartz 
23.52 
28.35 
14. 67 
5.84 
5.08 
22.26 
27.80 
13.10 
15.29 
4.63 
22.02 
43.37 
7.34 
11.12 
3.81 
15.06 
22. 79 
18. 86 
25.85 
3.71 
27.60 
28.35 
20.96 
10.56 
3.70 
33.12 
39. 47 
15.19 
5.56 
2.70 
1.62 
19.38 
Orthoclase 
28.35 
Albite 
12.05 
Anorthite 
15.84 
Biotiteo 
2.70 
Phlogopite a 
4. 16 
Hornblende" 
5.89 
6.03 
1.39 
.31 
1.99 
4.32 
1.16 
.31 
2.24 
Diopside 
Magnetite 
.86 
1.85 
.62 
.75 
1.28 
2. 16 
2.78 
.62 
4.11 
7.12 
1.62 
.31 
.56 
.92 
.31 
.75 
1.85 
Apatite 
.62 
Limonite 
.75 
Hematite 
3.52 
Calcite 
5.70 
Kaolin 
3.78 
1.84 
.90 
5.16 
3.09 
3. 61 
Serpentine 
2.48 
1.90 
Water 
"'i.'45' 
.97 
.76 
.34 
Sillimanite 
Wollastonite 
3.48 
98.94 
99.62 
99.63 
100.00 
100. 12 
99. 98 
99.95 
a Composition based on average of analyses in Dana's Manual of Mineralogy. 
A. Specimen 46612. Fresh intrusive andesite east of Granite Mountain. Analysis by R. D. Hall, 
University of Wisconsin. 
B. Specimen 46377. Slightly weathered intrusive andesite from Desert Mound. Analysis by R. D. 
Hall, University of Wisconsin. 
C. Specimen 46533. Fresh early trachyte from Antelope Range (No. 1 of flows). Analysis by R. D. 
Hall, University of Wisconsin. 
D. Specimen 46584. Andesite from same formation as specimen C north of Stoddard Mountain. 
Analysis by R. D. Hall, University of Wisconsin. 
E. Specimen 46521. Early rhyolite from Eightmile Hills (No. 2 of flows). Analysis by R. D. Hall, 
University of Wisconsin. 
E'. Specimen 46521. Early rhyolite. Recalculated on the basis of 100 percent after removing CaO 
and C0 2 of the infiltrated calcite. 
F. Specimen 40557. Latest trachyte from Antelope Hills (No. 5 of flows). Analysis by R. D. Hall, 
University of Wisconsin. 
G. Specimen 46586a. Dacite from Swett Hills (No. 7 of flows). Analysis by R. D. Hall, University 
of Wisconsin. 
