24 
ANALYSES OF KOCKS, U. S. GEOLOGICAL SURVEY. 
[bull. 168. 
VERMONT. 
1. ROCKS OF MOUNT ASCUTNEY. 
Analyses by W. F. Hillebrand, record Nos. 1621, 1657. Samples 
received from T. A. Jaggar, jr. Petrographic data furnished by 
R. A. Daly. 
A. Typical granitite. Contains quartz, orthoclase, plagioclase 
(microperthite), biotite, magnetite, sphene, apatite, and zircon. 
B. Basic segregation in granitite. Contains biotite, hornblende, 
quartz, plagioclase, microperthite, much sphene and apatite, some 
magnetite and zircon. 
C. Another sample of B. 
D. Syenite. Contains hornblende, augite, orthoclase, microperthite, 
plagioclase, biotite, quartz, magnetite, sphene, apatite, and zircon. 
E. Basic segregation in syenite. Contains hornblende, augite, 
microperthite, orthoclase, plagioclase, quartz, magnetite, zircon, and 
apatite. 
F. Syenite-porphyry. Contains orthoclase, quartz, nornoiende, 
magnetite, apatite, and zircon. 
A. 
B. 
c. 
D. 
K. 
F. 
Si0 2 
ALO, 
71.90 
14.12 
1.20 
.86 
.33 
1.13 
4.52 
4.81 
.18 
.42 
.35 
.11 
.04 
.05 
none 
.04 
.21 
.06 
.02 
trace 
56. 01 
al5. 19 
2.34 
4.89 
4.67 
4.85 
5.66 
2.16 
.36 
.90 
1.13 
.53 
59.27 
15. 76 
2.07 
3.57 
3.04 
3.69 
5.63 
3.33 
.23 
.74 
1.12 
.42 
.04 
.37 
trace 
trace? 
.30 
.42 
.03 
.07 
65. 43 
16.11 
1.15 
2.85 
.40 
1.49 
5.00 
5.97 
.19 
.39 
.50 
.13 
.11 
.23 
(?) 
.03 
trace? 
.08 
.05 
.07 
56.51 
16.59 
1.35 
6.59 
2.52 
4.96 
5. 15 
3.05 
.21 
.71 
1.20 
.41 
.04 
.24 
trace? 
.03 
.33 
.24 
.07 
.06 
73.03 
13.43 
..40 
1.49 
.14 
.79 
4.91 
4.54 
.18 
.35 
.30 
.06 
.06 
.15 
(?) 
trace 
trace? 
.08 
.03 
.09 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
Il 2 Oatll0°... 
H 2 above 100° 
Ti0 2 
P 2 5 
Zr0 2 
MnO 
.40 
.03 
trace? 
undet. 
undet. 
undet. 
.09 
(NiCo)O ..... 
BaO 
- CO, 
F 
CI 
FeS 2 . 
Less 
100. 35 
.03 
99.21 
100. 10 
.19 
100. 18 
.04 
100. 26 
.11 
100. 03 
.04 
100. 32 
99.91 
100. 14 
100. 15 
99.99 
a Including Zr0 2 
