CLARKE. J 
IGNEOUS AND CRYSTALLINE ROCKS. 
83 
2. LOWER QUINNESEC FALLS, MENOMINEE RIVER. 
Described by Williams, Bull. 62, pp. 89, 91. 
A. Gabbro-diorite, shore below falls, Wisconsin side. Aiwergnose. 
Contains saussurite, hornblende, and ilmenite. Some calcite in the 
saussurite. Hornblende partly altered to chlorite, and ilmenite to 
leucoxene. 
B. The same, schistose form. Contains less saussurite. Hornblende 
and ilmenite completely altered into chlorite and leucoxene. Calcite 
present, and also porphyritic feldspar. 
C. Silvery schist, adjoining B, and derived from gabbro. Resembles 
B in general, without the feldspar crystals. Calcite and sericite are 
present, and rutile in place of leucoxene. 
D. Dark, massive greenstone. Contains hornblende, chlorite, epi- 
dote, quartz, leucoxene, with some ilmenite and traces of original 
feldspar. 
E. Dark, schistose greenstone, forming a band in D. Chlorite 
entirely replaces hornblende, and rutile replaces leucoxene. Some 
feldspar, quartz, and calcite. 
Analyses by R. B. Riggs, record Nos. 384, 385, 386, 387, 388. Mate- 
rial dried at 105°. 
Si0 2 . 
A1 2 3 
Fe 2 3 
FeO. 
MgO 
CaO. 
Na 2 
K 2 0. 
H 2 0. 
C0. 2 . 
47.96 
16.85 
4.33 
4.17 
9.15 
13. 25 
1.25 
.30 
2.89 
.08 
100. 23 
B. 
49. 19 
18.71 
5.03 
4.04 
7.98 
5.92 
1.44 
.77. 
5.05 
1.82 
99. 95 
46.21 
18.38 
3.30 
3.90 
7.03 
6.28 
2.14 
.35 
3.82 
8.32 
7:; 
43.80 
16.08 
9.47 
10.50 
6.54 
7.81 
1.96 
.34 
3.99 
.08 
]•;. 
44.49 
16.37 
5.07 
5. 50 
7.50 
7.94 
2.59 
.56 
4.99 
5.38 
100.57 100.39 
