38 
ANALYSES OF ROCKS, U. S. GEOLOGICAL SURVEY. 
[NO. 228. 
E. Massive, coarse, altered diabase, Leverett. Ornose. Contains 
saussuritic feldspar with black hornblende. Analysis hy Eakins, 
record No. 1325. 
F. Tonalite, South Leverett. Andose. Dark green, chloritic. Con- 
tains reddish felspar, dark hornblende, and a network of dark-green 
epidotic quartz veins. Analysis by Eakins, record No. 1320. 
G. Biotite-granite, Moore's quarry, Florence. Lassenoxe. Very 
feldspathic. Quartz rare, with fluid inclusions. Feldspar mostly 
triclinic, orthoclase and microcline present in small quantities. Little 
muscovite, some rutile. Analysis by Eakins, record No. 1-114. 
Rocks E, F, and G, are described by Emerson in Mon. XXIX. 
H. Holyokeite, east foot of Mount Tom, Northampton. Probably 
tuolumnose. Described by Emerson in Journ. Geol., vol. 10, p. 508. 
Contains albite, 70 per cent; orthoclase, 9.-1 per cent; calcite, 16. -1 per 
cent, with minor amounts of ilmenite, dolomite, chalcopyrite, p} T rite, 
and apatite. Analysis by W. F. Hillebrand, record No. 1921. 
Si0 2 . 
A1A 
Fe 2 3 
FeO. 
MgO 
CaO. 
Na,0 
K 2 
H 2 Oatl05°.... 
H 2 above 105° 
Ti0 2 
co 2 
Zr0 2 
PA 
s 
55.51 
16.51 
1.68 
4.57 
(>. 73 
ti. 73 
3.19 
2.46 
/ L53 } 
.91 
73. 27 
15. 51 
.33 
1.14 
.15 
2.74 
4. 79 
1.66 
.68 
.10 
MnO 
BaO. 
Cu_. 
09 
trace 
trace 
trace 
11 
02 
100. 25 100. 12 
trace 
53.83 
16. 36 
.89 
.13 
9. 81 
7.89 
1.58 
.15 
36 
.86 
7.47 
.02 
.11 
.17 
undet. 
(?) 
.14 
100. 37 
99. 
