CLARKE.] 
IGNEOUS AND CRYSTALLINE ROCKS. 
55 
E. Biotite-granite, Dorseys Run, Howard County. Yellowstonose. 
Typical, dark colored. Quartz, feldspar, and biotite, with accessory 
allanite and epidote. (Keyes.) 
F. Same locality, light-colored dikes. Toscanose. 
G. Inclusions in E. &R. 6 2 of tonalase. Derived from gneiss. 
H. The typical gneiss of the Dorseys Run area. Perhaps of sedi- 
mentary origin. 
Descriptions by Keyes. Analyses by Hillebrand. The remarks 
appertaining to B and C apply here also. Record No. 1220. 
Si0 2 . 
A1 2 3 
Fe 2 3 
FeO. 
MgO 
CaO. 
Na 2 
K 2 0. 
H 2 0. 
Li 2 
62.91 
19. 13 
.98 
3.20 
1.69 
4.28 
3.94 
3.38 
.63 
trace 
100. 14 
P. 
70.45 
15.98 
.75 
1.84 
.77 
2.60 
3.83 
3. 59 
.45 
trace 
100. 26 
57.33 
15. 31 
3.39 
8.19 
4.36 
3.95 
1.22 
4.57 
1.80 
trace 
100. 12 
ii. 
48.92 
16.57 
4.21 
9.18 
5.98 
9.69 
2.47 
1.56 
1.68 
trace 
100. 26 
