52 



tion in the Kittatinny Valley, we commence with that axis, or 

 rather, probably, that chain of axes, which we find ranging in the 

 prolongation of the Pochuck Mountain. 



That the oval-shaped primary hill, called the Pochuck Moun- 

 tain, owes a part at least of its present altitude, to an axis of 

 elevation passing through it longitudinally from north-northeast, 

 to south-southwest, is rendered sufficiently apparent by the anti- 

 clinal posture of the limestone reposing at its base ; that which 

 flanks it on the southeast dipping towards the Pochuck Valley ; 

 while that at its northwest foot has an inclination towards the 

 valley of the Wallkill, in the opposite direction. The valley of 

 Black and Warwick creeks, which I here call the Pochuck 

 Valley, contains the limestone in a trough, considerably disturbed, 

 however, from a symmetrical synclinal structure by a series of 

 igneous dikes of mineral matter, ranging at broken intervals, at 

 a nearly straight line from Amity, in New York, to a point a 

 httle south of Hamburg, which either locally derange, or alto- 

 gether obliterate the dip of the limestone by fusion and recrystal- 

 lization. The prolongation past Hamburg of this synclinal axis, 

 is not cbarly traceable, in consequence, most probably, of the 

 close approach of the uptilting primary rocks of the Hamburg 

 Mountain to those of the Pochuck Mountain ; at this vicinity the 

 upheaving influence of the former countervailing, for a limited 

 space, the anticlinal axis of the Pochuck Mountain, causing all 

 in the tract immediately southwest of Hamburg to dip along a 

 certain distance towards the northwest. But tracing what ought 

 to be the line of the Pochuck axis, a little further towards the 

 southwest, we find distinct evidence throughout a belt having a 

 somewhat confused anticlinal dip, of its prolongation under the 

 limestone between Hamburg and Munroe. It would seem not to 

 extend as far as the turnpike, south of ihe village of Lafayette ; 

 for though the limestone displays a northwestern dip along the 

 margin of the slate, both at Munroe and on the turnpike, we can- 

 not find in the proper places any corresponding dip to the south- 

 east, which might give proof of a continuation of the axis so far 

 towards the southwest. 



Another axis of elevation is traceable in Pimple Hill, for the 

 limestone at its southeastern base is seen dipping from the hill, or 

 towards the southeast; and we have already recorded the north- 



