50 
ANALYSES OF KOCKS, U. S. GEOLOGICAL SURVEY. 
[BULL. 168. 
4:. MISCELLANEOUS ROCKS. 
A. Typical diabase, Rocky Ridge. Analyzed for J. S. Diller, but 
not described. Analysis by E. A. Schneider, record No. 1370. 
B. Ottrelite-phyllite rock, Liberty, Frederick County. Analyzed 
for S. H. Williams, but not described. 
C. Ottrelite separated from B. Analyses B and C by L. G. Eakins, 
record No. 1349. 
D. Quartz-schist, Shoemaker quarry, near Stevenson Station, Green 
Spring Valley. Described by Bay ley in Bull. 150, p. 302. Contains 
quartz, muscovite, occasional tourmalines, microcline, zircon, and iron 
stains. Analysis by Schneider, No. 1370. P. R. C. 119. 
E. Mica separated from D. Analysis by Schneider, No. 1377. 
F. Sericite-schist, Ladiesburg. Described by Bayley in Bull. 150, 
p. 317. Contains quartz, sericite, chlorite, a mineral thought to be 
kaolin, zircon, iron oxide, and rutile. Analysis by George Steiger, 
record No. 1600. P. R. C. 126. 
G. Another sample of F. Analysis by Schneider, No. 1370. 
A. 
B. 
C. 
D. 
E. 
F. 
G. 
Si0 2 
51.68 
15.87 
1.46 
8.43 
7.84 
11.08 
1.86 
.34 
.16 
.15 
.72 
.12 
.15 
34.92 
32.31 
10.21 
8.46 
1.13 
.36 
2.12 
1.87 
| 5.29 
3.37 
.23 
trace 
23.40 
39.31 
5.14 
21.94 
2.18 
trace 
.20 
.20 
| 6.81 
1.19 
trace 
trace 
91.65 
1.59 
3.57 
.21 
.17 
none 
.07 
1.93 
.60 
.13 
none 
trace 
44. 93 
29.81 
| 6.10 
1.16 
.50 
10.28 
1.38 
4.88 
1.05 
trace 
trace 
.22 
57.24 
23.48 
3.19 
4.87 
.93 
.09 
1.18 
3.55 
.33 
4.65 
.08 
.09 
none 
58. 11 
21.84 
2.62 
5.63 
1.85 
none 
.97 
3.66 
.35 
4.05 
.81 
.21 . 
.19 
A1 2 3 
Fe 2 3 
FeO 
MgO 
CaO 
Na 2 
K 2 
H 2 Oatl00°... 
H 2 above 100° 
Ti0 2 ........ 
P„0* 
MnO 
Li 2 
F 
99.86 
100. 27 
100. 37 
99.92 
100. 31 
99.68 
100. 29 
