W. M. Fontaine — Vespertine Strata of Virginia. 



increasing depth to which they are buried, the Vespertine 

 strata are rarely brought to the surface in that direction by the 



As we go south of Pocahontas the westward thrust which 

 has affected this region, causes an increased elevation and flex- 

 ing of the rocks. The structure of the Alleghany passes from 

 monoclmal to anticlinal, with increasing steepness of dip so 

 that, in the vicinity of the White Sulphur Springs, where pen- 

 etrated by the tunnel for the Chesapeake & Ohio Railroad, the 

 strata stand nearly vertical. 



Lower and lower rocks enter into its composition, in passing 

 southward. As Rogers has shown, in the north, where mono- 

 clinal dips prevail, the lowest rocks seen in the east face of the 

 mountain are those of No. IX or Catskill ?. But near the 

 White Sulphur, the core of the mountain is composed of the 

 lowest Chemung, and, probably, Hamilton strata. 



The development of an anticlinal structure, with increasing 

 steepness of dip in passing southward, has had the effect of 

 causing a belt of Vespertine rocks to be brought down on the 

 east side of the mountain, and caught in a synclinal fold. This 

 gives us the small coal beds seen near the Lewis Tunnel. 

 At the same time the increase in the elevation and flexing of 

 the strata southward from the northern part of Pi 

 county has brought up rocks lower than the Catskill?. not only 

 in the Alleghany but over a belt about ten miles wide to the 

 west, so that the east limit of the unbroken Vespertine is 

 thrown off to the western side of this area. 



This belt shows strata all the way in the series, from the 

 Onskany to the Vespertine. The formei bat. h mi, ,- i th. 

 lowest eroded places, and the latter shows merely small uneroded 

 remnants of its lower portion. In the vidnitv .">f the White Sul- 

 phur Springs, the strata throughout this area seem to be dis- 

 posed in closed and contorted aiitidinals overturned to the 

 westward, which are separated by comparatively broad belts, in 

 which the beds show moderately steep dips. 



This disturbed belt is separated bv a line of fault from the 

 Vespertine strata. Here the transition is verv abrupt, to a 

 region which shows rei n : , (1 „.,.'. | >„ ,;; ] ;., „_,,,,./ 



description of the geology of the eastern corner of Monroe 

 county would seem to show that the elevation of strata lower 

 than the Vespertine in the Alleghany, and the belt to the west 

 of it, is not maintained beyond the northeastern border of this 

 county; for there we find that the eastern outcrop of the Ves- 

 pertine area has closed in upon the Alleghanv. while within 

 the county this mountain chain is continued'in Little Moun- 

 tain, which is composed of upturned Vespertine strata 



