a eS hULlULlmUmlUlUlmlmLlULLULlUllee 
J. L. Campbell— Geology of Virginia. 443 
from a bed twelve or thirteen feet thick, interstratified with 
shales and other beds of impure limestone. It dips steeply to 
the northwest, and again crops out at the base of Salling’s 
Mountain, on the west side of the little valley in which the two 
rivers meet. Over it lies a part of the Quebec (80), that has 
escaped the denuding agencies that have operated so exten- 
sively over the whole of the Great Valley. It crops out at a 
number of points along the James River near the cement quar- 
ries, and along the base of Salling’s Mountain. We have thus 
asynclinal trough of limestone resting upon the Primordial 
X shales and sandstones, which we find rising again on the west 
side and forming the mass of the bordering mountain. 
na depression of Salling’s Mountain, about half-a-mile to 
the right of the point cut by the section, and where the turn- 
pike leading from Balcony Falls to the Natural Bridge crosses, 
we find the shales-and thin beds of sandstone of 2ad, 7, extend- 
ing to the top of the ridge, but where the mountain is more 
elevated, the heavy y beds of Scolithus sandstones (2ab, 6), form 
the core of the ridge, all dipping steeply to the southeast: 
while beyond, the mountain shales of 7 again appear, dipping 
toward the mountain and apparently beneath the sandstone 
which elsewhere underlies them. Then as we descend into the 
ing been pressed out and subsequently swept off. This part of 
the section will be readily understood from simple inspection. 
Salling’s Mountain will serve as a type of a considerable 
number of nearly parallel outliers of the main Blue Ridge 
