90 



order and dipping almost uniformly to the east, occupy nearly all 

 the space west from this to the commencement of the sandstones of 

 the ridges subordinate to the North mountain. Layers of a very 

 silicious limestone, and bands of sandstone, occasionally occur. 

 Between Harper's Ferry and Winchester, two alternations of the 

 slate and limestone may be observed ; the most eastern bed, com- 

 posed of slate, dipping east at an angle of 30° into the valley of the 

 Shenandoah, succeeded by a broad range of limestone of a dark 

 blue aspect, and but little veined, dipping in the same direction, next 

 to which is another bed of slate followed by one of limestone, both 

 dipping as before. 



Approaching the northern extremity of the Massanutten moun- 

 tain, the belt of limestone presents interesting peculiarities, some of 

 which may with great probability be referred to the proximity of 

 that lofty range. It is here traversed by large veins of calcareous 

 spar, in general running across the direction of the edges at a con- 

 siderable angle, and it is thrown off from the flank of the mountain 

 with a reversed or western dip. The veined condition of the rock 

 distinctly pointing to a period during which it was subjected to 

 violent actions, cleaving it into countless fissures, subsequently filled 

 by infiltration with the pure material of the rock, taken in con- 

 nexion with its inverted dip along the mountain flank, gives great 

 probability to the idea that the upheave of this range took place 

 subsequently to the formation of the rocks of the valley, and that 

 thus the fissured structure and changed direction of the adjacent 

 rocks, were merely consequences of the elevation of this enormous 

 mass. In connexion with this curious point of inquiry, the in- 

 vestigation of the materials and structure prevailing in the Massa- 

 nutten mountain, cannot fail to prove interesting to the geology of 

 the state. Such an examination, moreover, promises more than any 

 other to reveal the geological relations of the valley with the regions 

 bounding it on either side, and thus to solve some of the most 

 curious problems with which the student of our geology at pre- 

 sent cannot fail to be embarrassed. 



In the valleys of this mountain slates and limestones occur, and 

 rumour intimates that coal even has been found. Beds of a coarse 

 conglomerate of very peculiar structure, constitute an important 

 portion of its mass, and furnish the material of mill-stones, now much 

 in use. Limestone is said to occur on the summit of the Peaked 



