W. M. Fontaine~—Geology of the Blue Ridge. 10) 
be required. These can best be explained by assuming the 
action of ice through this gap. In passing over the coarse de- 
composing syenites, which form the lower part of the mountain, 
ting them. This, which has all the characters of a true igneous 
substance, has made its exit principally on the west side, in the 
It is composed principally of a peculiar orthoclase of a sea- 
green color, its pl i i 
23 aie bearing on this question. : 
n this article I have devoted most space to the geological 
structure of the two mountain chains and to the massive crys- 
ay rocks, since my object in making the examination was 
; discover whether any igneous rocks existed in them, and, if 
°, to determine the part they played in their structure. 
Morgantown, West Virginia, Oct. 16th. 
