34 
ANALYSES OF EOCKS, U. S. GEOLOGICAL SUKVEY. [no. 228. 
2. AMPHIBOLITE. 
Rocks A to G are described by Emerson in Mon. XXIX. 
A. Amphibolite, Bernardston. A black, heavy, massive horn- 
blende rock. Analysis by L. G. Eakins, record No. 1327. 
B. Porphyritic amphibolite, Heath. Analysis by Eakins, record 
No. 1325. 
G. Amphibolite, New Salem. Analysis by Eakins, record No. 1325. 
D. Amphibolite, Whitmans Ferry, Sunderland. Thin, shaly, apha- 
nitic. Analysis by Eakins, record No. 1325. 
Si0 2 .. 
A1 2 3 - 
Fe 2 3 . 
FeO.. 
MgO. 
CaO.. 
Na 2 0. 
K 2 0.. 
H 2 0.. 
Ti0 2 .. 
PA- 
Cr 2 3 . 
MnO. 
BaO.. 
C0 2 . . 
51.72 
16.51 
1.72 
9.56 
6.58 
8.89 
2.74 
.34 
.51 
1.39 
.23 
trace 
trace 
100. 19 
B. 
51.38 
18.01 
3.30 
8.53 
5.08 
6.27 
5.34 
.18 
.56 
•1.07 
.18 
.19 
trace 
100. 09 
45.48 
19.43 
.13 
6.58 
11.08 
10.66 
2.28 
.11 
3.17 
.77 
.14 
trace 
trace 
.01 
.20 
100. 04 
49.86 
15.50 
2.99 
8.01 
7.79 
8.89 
3.26 
.72 
1.51 
1.58 
.11 
•0,7 
trace 
100. 29 
