CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
83 
L. Garnetiferous gabbro, Granite Falls. Described by W. S. Bayley 
in Bull. 150. p. 282. Contains plagioclase, augite^ garnet, magnetite, 
a little hornblende, some quartz grains, and apatite. Analysis by 
H. N. Stokes, record No. 1296. Sp. gr. 3.105. P. R. C. 109. 
M. Gabbro-diorite, Minnesota Falls. Described by Bayley in Bull. 
150, p. 369. Essentially plagioclase and hornblende, with some kaolin, 
augite, and biotite. Analysis by Stokes, No. 1296. Sp. gr. 2.935. 
P. R. C. 144. 
N. Quartz-norite-gneiss, Odessa. Described by Bayley in Bull. 15G, 
p. 358. Contains quartz, plagioclase, pyroxene, biotite, garnet, mag- 
netite, and sulphide of iron. Analysis by Stokes, No. 1296. Sp. gr. 
2.770. 
O. Mica-schist, bed of Cross River, near Gunflint Lake. Descrip- 
tion furnished by C. R. Van Hise. Contains biotite, quartz, feld- 
spar (?), and pyrites. Analysis by T. M. Chatard, record No. 896. 
P. Actinolite-magnetite-schist, SE. i of SE. \ of sec. 34, T. 61 N., 
R. 12 W. Described by Bayley in Amer. Journ. Sci. , 3d series, vol. 46, 
p. 178. Mainly actinolite and magnetite. Analysis by W. H. Melville, 
record No. 1403. 
Q. Magnetite rock near the preceding, also described with P by 
Bayley. Analysis by Melville, No. 1403. 
L. 
M. 
N. 
O. 
p. 
Q. 
Si0 2 
52.31 
18.35 
5.90 
11.06 
1.00 
7.33 
2.90 
.49 
| .35 
48.29 
20. 87 
1.13 
4.93 
7.54 
14. 32 
1.77 
.38 
| .89 
61.04 
16.97 
64.77 
14. 45 
1.84 
4.54 
2. 34 
2. 33 
1.37 
5.03 
.07 
1.92 
.60 
.20 
.11 
.60 
.41 
12. 35 
.10 
58.68 
21.34 
4.08 
1.91 
trace 
1.16 
1.81 
69. 08 
27. 10 
.25 
.53 
A1 2 3 
Fe.,Oo 
FeO 
5.58 
3.62 
5.99 
1.96 
.55 
} ■« 
MgO 
CaO 
Na 2 
K 2 
H 2 Oatl05°.„ 
H 2 above 105° 
Ti0 2 .. 
} ■» 
.12 
.25 
1.22 
none 
.06 
.33 
P 9 0, 
MnO 
S0 3 
co 2 
FeS . 
a 3. 73 
99.69 
100. 12 
99.87 
100. 58 
100.24 
100. 32 
a Probably pyrrhotite. 
