338 CONNECTION OF Tin:RI\IAL SPRINGS IN VIRGINIA 



the tliormal, occurs Dibbrcll's Sprins^, a cold alkalino-sulphureous 

 water, such as clutraclerlzes the lower and more calcareous por- 

 tion of these slaty rocks. 



The discharge of water at Wilson's thermal is abundant, but 

 is accompanied by very little gas. The spring contains a small 

 amount of uncombined carbonic acid, together with a considera- 

 ble proportion of saline matter. 



Section VIII. From Bath across the Cacapon Mountain. 



The Cacapon or Capon Mountain, formed by the union of 

 several contiguous parallel axes, which arise at various points 

 within a distance of fifty miles from the Potomac river, attains 

 its greatest altitude and breadth about eighteen miles southwest- 

 ward of the line of our Section, beyond which, in its prolongation 

 towards the river, it gi-adually declines. Where most largely 

 developed, a slight roll of the strata makes its appearance near 

 its southeastern base, which, soon assuming more importance, 

 forms the distinct anticlinal of Warm Spring Ridge. This, in its 

 prolongation towards the northwest, gi-adually loses its anticlinal 

 character by the obliteration of the narrow trough betsveen it and 

 the Cacapon axis, and forms at the Potomac a low flanking hiU 

 of southeast dipping rocks. Where the thermals of Bath arise, 

 the anticlinal flexure is still in part preserved in a sharp but tran- 

 sient change of dip in the rocks a little westward of the Springs. 

 Owing to an eiTor in reducing this Section, the space between the 

 .centre of the Eastern Cacapon axis and the position of the springs, 

 is much too great. Contracting this interval, it will appear that 

 the position of these thermals agrees in all important points with 

 that of the springs on the southeastern flank of the Mill Mountain, 

 Section I, and of the gi'oup in Section IV. 



These copious springs make their appearance near the junc- 

 tion of Fors. VII and VIII, at the southeastern base of the 

 Warm Spring Ridge, here faced by the massive jointed sand- 

 stone of the former. The gas which accompanies the water, 

 though consisting mainly of nitrogen, contains a rather larger 

 proportion of oxygen than is found in the other principal iher- 



