92 
ANALYSES OF ROCKS, V. S. GEOLOGICAL SURVEY. 
[no. 228. 
P. Red granitic rock resembling D, but with more dark spots, found 
in contact with the purplish slate, N. Liparose. Consists mainly of 
red feldspar, quartz, and chlorite. Analysis by J. E. Whitfield, record 
No. 519. Dried at 104°. P. R. C. 1014. 
Q. Groundmass of red mottled quartzite. Analysis by W. F. Hille- 
brand, record No. 499. P. R. C. 1022. 
R. Green mottlings from Q. Mostly quartz and sericite. Analysis 
by Hillebrand, record No. 498. 
S. Another sample of the green mottlings, selected with especial 
care. Analysis by L. G. Eakins, record No. 1058. 
T. Brilliantly red vitreous quartzite. Analysis by R. B. Riggs, 
record No. 574. Dried at 105°. P. R. C. 1008. 
Si0 2 ... 
A1 2 3 - 
FeA 
FeO.. 
MgO . 
CaO.. 
K 2 0. 
H 2 0. 
Ti0 2 
PA- 
Zr0 2 
MnO 
SrO. 
BaO. 
Li 2 
so 3 . 
p. 
Q. 
68.36 
76.57 
13. 76 
9.21 
2.65 
1.67 
2.75 
3. 94 
.68 
1.51 
.70 
.73 
3.56 
3.07 
4.48 
1.02 
.98 
1.89 
1.57 
.42 
.33 
trace 
R. 
trace 
undet. 
undet. 
none 
.66 
100. 48 
none 
.05 
trace? 
none 
trace 
100. 08 
77.70 
7.67 
3. 55 
3.29 
1.83 
.26 
1.96 
1.04 
"2.36 
.30 
none 
.04 
(?) 
none 
trace 
s. 
83.27 
7.81 
1.99 
1.81 
1.59 
. 20 
1. 1L 
2.32 
trace 
trace 
100. 00 
100. 29 
83.69 
7.50 
1.81 
.38 
.35 
.39 
2.46 
2.61 
.72 
trace? 
trace 
undet. 
undet. 
99.91 
« Determined by difference. 
