20 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. [bull. 168. 
E. Diabase (basaltic glass), Mars Hill. Not resolvable into minerals. 
F. Rh^olite, Haystack Mountain. Contains quartz in a groundmass 
of orthoclase. 
G. Volcanic tuff, southeast base of Castle Hill. Contains fragments 
of trachyte, andesite, devitrified glass, and lapilli. 
H. Diabase, Aroostook Falls, near Maine boundary line. Dike. 
Contains plagioclase, pyroxene, and pyrite. 
Si0 2 
AlA 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 Oatl05°... 
H 2 above 105 
Ti0 2 
PA 
Zr0 2 
Cr 2 8 
VA 
FeS 2 
NiO 
MnO 
SrO 
BaO 
C0 2 
42.25 
16.87 
5.24 
10.72 
6.91 
3.33 
3.96 
.77 
.43 
5.58 
2.93 
.34 
none 
.03 
.07 
trace 
.01 
.40 
none 
trace ? 
none 
99.84 
75.98 
12.34 
.85 
.93 
.15 
.13 
4.02 
4.44 
.24 
.64 
.17 
.03 
.03 
(?) 
(?) 
none 
none 
trace ? 
trace ? 
.07 
none 
100. 02 
31.42 
11.57 
2.37 
7.48 
5.32 
16.71 
2.26 
.74 
.76 
4.17 
2.30 
.46 
none 
trace 
.06 
.16 
trace 
.38 
none 
.64 
13.13 
99.93 
49.64 
15. 07 
1.66 
8.82 
5.43 
7.23 
4.19 
.89 
.45 
2.81 
2.32 
.29 
none 
trace 
.04 
.79 
trace 
.25 
.05 
.02 
.32 
100. 27 
Traces of lithia present in all. CI and F not looked for. 
