278 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[BULL. 168. 
SPATES AND SHALES. 
VERMONT. 
Samples A to I, inclusive, are described by T. Nelson Dale in 19th 
Ann., Part III. Analyses by W. F. Hillebrand, record Nos. 1567, 
1656. Roofing slates of Cambrian age. 
A. McCarty quarry, South Poultney. 
B. Unfading green, Eureka quarry, Poultney. 
C. Sea green, Griffith and Nathaniel quarry, South Poultney. 
D. Sea green, Rising and Nelson's quarry, Pawlet. 
E. Sea green, Brownell quarry, Pawlet. 
F. Black, American Black Slate Company, Benson. 
A. 
B. 
c. 
D. 
E. 
F. 
Si0 2 
61.63 
16.33 
4.10 
2.71 
2.92 
.50 
1.26 
5.54 
.31 
3.24 
.68 
.16 
.09 
.06 
.41 
.04 
none 
59. 27 
18.81 
1.12 
6.58 
2.21 
.42 
1.88 
3.75 
.32 
3.98 
.99 
.11 
.13 
.05 
.21 
.15 
none 
62.37 
15.43 
1.34 
5.34 
3.14 
.77 
1.14 
4.20 
.34 
3.71 
.74 
.06 
. 22 
.07 
.87 
.06 
trace 
67.76 
14.12 
.81 
4.71 
2.38 
.63 
1.39 
3.52 
.23 
2.98 
.71 
.07 
.10 
.04 
.40 
.22 
none 
59.84 
15.02 
1.23 
4.73 
3.41 
2.20 
1.12 
4.48 
.41 
3.44 
.74 
.09 
.34 
.09 
2.98 
.05 
trace? 
59. 70 
16. 98 
.52 
4.88 
3.23 
1.27 
1.35 
3.77 
.30 
3.82 
.79 
.16 
.16 
.08 
1.40 
1.18 
.46 
ALO., 
FeA 
FeO 
MgO 
CaO.. 
Na 2 
K 2 
H 2 at 100° . . . 
H 2 above 100° 
Ti0. 2 
PA 
MnO . . 
BaO 
CO, 
FeS 2 
C 
99.98 
99.98 
99.80 
100. 07 
100. 17 
100. 05 
All six contain traces of lithia, of sulphates, and of nickel or cobalt. 
