W. M. Fontaine— Vespertine Strata of Virginia. 39 



With this disappearance of the elevated belt of disturbed 

 Devonian strata, the fault which bounded it on the west also 

 vanishes, but is succeeded by a much more important one, 

 which begins some distance to the east of the termination of 

 the Alleghany, in the northeastern edge of Monroe county. 

 The rapid increase in the magnitude of this fault to the south- 

 west soon swallows clown the Devonian beds of the Alleghany, 

 with their overlying bands of Vespertine coal beds, and brings 

 the eastern outcrop of the Vespertine close to Lower Si hi nan 

 strata. This fault, which runs not far to the west of Peters 's ;.ud 

 Ka>t River Mountains, bounds the Vespertine outcrop in that 

 direction. 



Every observer who has examined the structure of the 

 country to the east and west of this fault, in the region extend- 

 ing from Monroe county to the southwest, has been struck with 

 the remarkable difference in the amount of disturbance exhib- 

 ited by the strata on the opposite sides of it. Prof. Lesley has 

 given an excellent account of the condition of the country to 

 the southeast of the fault above mentioned. The entire area here 

 has been fractured, displaced, and folded, showing a truly as- 

 tonishing amount of disturbance. On the northwest, or western 

 side, we find the beds sometimes : turned, but 



they pass into an almost horizontal position in a short distance 

 to the west. This is well shown in Prof. Lesley's section of 

 Stone Mountain, where the conglomerate series is thus affected. 

 Prof. Eogers, in his section of the strata in the northeast corner 

 of Monroe county, gives a good example of this condition of 

 things. Here the" partially overturned beds of the Vespertine 

 and TJmbral, lying in the immediate vicinity of the fault, 

 rapidly come down to nearly a horizontal position. In my ac- 

 count of the section near Greenbrier River, a similar structure 

 will be shown. But here the line of fault separating the dis- 

 turbed from the undisturbed region, is a minor one, developed 

 by the rise of the Devonian belt near the White Sulphur 

 Springs. 



While the direction of this fault is thrown more in a 

 northerly direction, and hence farther to the west than that 

 of the one above described, yet it occupies the same relative 

 position, and performs the same office, viz : that of checking 

 the propagation of the disturbance through the strata to the 

 west of it This fault does not seem to continue far north, 

 certainly not beyond Pocahontas county. 



The country everywhere to the west of these last lines of 

 fault, from Greenbrier county nearly to the Tennessee line, 

 with the exception of a few undulations and disturbances in 

 the vicinity of the fault, shows a prevailing northwest dip, as 

 far as the Ohio River, which, as we go in that direction, brings 



