ANALYSES OF EOCKS, U. S. GEOLOGICAL SURVEY. 
[bull. 168. 
F. Quartz-mica-diorite. Contains biotite, hornblende, augite, hyper- 
sthene, plagioclase, orthoclase, and quartz. Analysis by Whitfield, No. 
921. 
G. Quartz-mica-diorite. Contains biotite, hornblende, plagioclase, 
pyroxene, quartz, and orthoclase. Analysis by Whitfield, No. 921. 
H, I, J. Quartz-mica-diorites. Contain hornblende, biotite, plagio- 
clase, orthoclase, and quartz. Analyses by Whitfield, Nos. 921 and 
830. 
Si0 2 . 
A1A 
Fe 2 3 
FeO. 
MgO 
CaO. 
Na 2 
K 2 . 
H 2 0. 
Ti0 2 . 
PA. 
MnO 
Li 2 0. 
so 3 .. 
CI... 
65.11 
16.21 
1.06 
3.19 
2.57 
3.97 
4.00 
2.51 
.94 
.71 
.02 
none 
.04 
trace 
none 
100. 33 
65.60 
17.61 
.95 
2.76 
1.49 
3.72 
4.36 
2.36 
.59 
.75 
.16 
none 
.03 
trace 
none 
100. 38 
64.85 
16.57 
2.10 
2.15 
2.14 
4.01 
3.71 
3.10 
.35 
.91 
.14 
none 
none 
trace 
none 
100. 03 
66. 05 
16.96 
2.59 
1.38 
2.08 
3.37 
4.20 
2.53 
.69 
.34 
trace 
none 
none 
.03 
trace 
100. 22 
67.54 
17.02 
2.97 
.34 
.13 
3.36 
4.62 
2.28 
.55 
.80 
trace 
trace 
.03 
.26 
.15 
100. 05 
