J. L. Campbell—Geology of Virginia. 439 
Besides these constituents we find the mass at Balcony Falls 
containing, in some places, considerable quantities of epidote, 
both crystalline and amorphous, giving the rock a green color, 
and in others numerous crystals of garnet. 
The bedded rocks (1, a, 6,) that rest upon the syenite, are 
very much metamorphosed, are gneissoid in character, and di 
toward the southeast. These are succeeded by beds of r 
and brown slates. Then follows a bed of forty or fifty feet of 
conglomerate quartzite, bearing some resemblance to the con- 
Over this again we find another bed of slate. These beds all 
dip towards the southeast, while their upper margins reac 
are entirely unconformable. Such are the Archean roc 
Starting again on the northwest side of the granulite, let us 
briefly sketch the remarkable beds that make up the remainder 
of this massive range. In the Archzean rocks we have just 
described there are no traces of fossil remains, nor do we ni 
any in the lowest beds of what we call Primordial. If organic 
mains have ever been imbedded in them here, they have 
(July No.), the classification of Professor Rogers in his reports 
was employed, and subdivisions of my own introduced. In a 
my main object—the Silurian limestones—a very brief descrip- 
tion of them was deemed sufficient; but now they become = 
prime importance in our discussion, and demand a more ful 
and detailed examination. 
* Professor Rogers himself has partially adopted this system in his “ee 
the Geology of Virginia, ia, in Macfarlane’s Geol. R. R. Guide. 
