84 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [no. 228. 
3. UPPER QUINNESEC FALLS, MENOMINEE RIVER. 
Described by Williams, Bull. 62, pp. 104, 113, 114, 121. 
A. Light greenstone. Auvergnose. Contains hornblende, feldspar 
much altered to saussurite, ilmenite with leucoxene border, and some 
secondary quartz. 
B. Mica-diorite-porphyry. I. 5. 3. )+. Mainly andesitic feldspar 
and biotite, with apatite, zircon, sphene, and some calcite. 
C. Biotite-gneiss, Michigan side. Contains biotite, soda orthoclase, 
and quartz. Sphene common, zircon and apatite present. 
D. Schistose quartz-porphyry. Toscanose. Contains quartz, feld- 
spar, sericite, some chlorite, anatase, and tourmaline, with zircon and 
apatite sparingly. A, B, and D are from the Wisconsin side of the 
river. 
Analyses by R. B. Riggs, record Nos. 392, 393, 394, 395. Material 
dried at 105°. 
Si0 2 . 
A1 2 3 
Fe 2 ? 
FeO. 
MgO 
CaO. 
Na 2 
K 2 0. 
H 2 0. 
C0 9 . 
48. 35 
15. 40 
4.04 
4.63 
11. 61 
10.38 
1.87 
.35 
3.60 
100. 31 
i',. 
54. 83 
25. 49 
1.61 
1.65 
1.96 
6.08 
5.69 
1.87 
1.18 
.18 
100. 54 
67.77 
16.61 
2.06 
1.96 
1.26 
1.87 
4.35 
2.35 
1.69 
.19 
100. 11 
66.69 
16.69 
2.06 
.93 
1.15 
1.40 
2.46 
5.23 
1.70 
1.421 
). 73 
4. SCHIST FROM THE ARAGON IRON MINE. 
Described by Bayley in Mon. XLVI, p. 122. Consists of quartz 
and micaceous minerals, either talc or kaolin and serpentine. Some 
limonite is present. Analysis by George Steiger, record No. 1835. 
Si0 2 49. 56 
A1 2 3 10. 12 
Fe 2 3 5. 87 
FeO 13 
MgO 20. 53 
CaO 72 
Alkalies none 
H 2 at 1 10° 4. 5( 
H 2 above 110° 7.6 
Ti0 2 6 
PA o 
MnO trac 
CO., non 
