VIRGINIA. 



185 



At a distance of 23 miles, in a northwest direction, is the sheet of water called "Mountain Lake," 

 situated near the top of Salt Pond Mountain, at a height of 4,000 feet above tide. Here the Potts 

 and Johns Creek Mountains and the other ridges of 5 a. b. coalesce at their southwest termination, 

 iuto a lofty rugged table-land, overlooking the New River, and commanding wide views. 



21. A few miles south, the Lick Mountain range divides the valley for some miles into two, and 

 in the southern of these belts, on the New River, below the mouth of Cripple Creek, are the 

 Austenville lead mines, in 3 b., near the Primal 2 b. of Poplar Camp Mountain, and about 15 miles 

 distant from Wytheville. 



22. From this point a short branch railroad leads north into the valley of the north fork of the 

 Holston River, bet\yeen Walker's Mountain, 5 a., &c., and Poor Valley ridge. Vespertine 13 c., &c., 

 which flanks the Clinch Mountain on the southeast side. Here, near Saltville, are the remarkable 

 salt wells, which penetrate into a thick mass of rock-salt; and in the same vicinity, and at various 

 points higher up the valley, for a distance of 20 miles, beds of gypsum have been opened and 

 extensively wrought. These deposits are found near and in a line of fault, along which the Siluro- 

 Cambrian 3 c. 4 a., of the southeast side of the valley, has been made to abut against and some- 

 times over-ride the Umbral 13 b., which, with the Vespertine 13 a. of the Poor Valley Mountain, 

 form a belt on the northwest side of the valley. Both deposits are most probably referable to the 

 Subcarboniferous period. The fault here spoken of extends, with some local changes of character 

 and direction, in a west-by-southwest course, from a point in Giles county to the Tennessee line, a 

 distance of 125 miles, and is prolonged many miles into Tennessee. WILLIAM B. ROGERS. 



23. So few details have been published on the geology of Virginia, that no chapter in this 

 volume will be more welcome to geologists than this, which has been wholly and very carefully 

 prepared by Professor William B. Rogers, late State Geologist of Virginia. J. M. 



