63 



western dip of its beds on the western side, or between Munroe 

 and the turnpike. Thougiq the stratification is locally much con- 

 torted and disturbed in the valley between Pimple Hill and Ham- 

 burg Mountain, by the violent disrupting igneous agencies, which 

 have so extensively altered the texture of the limestone, yet the 

 general structure of this belt is that of a somewhat irregular 

 synclinal trough, which may be traced past Sparta into the valley 

 of Lubber run, though with many interruptions to the regularity 

 of the synclinal axis. The portion of this valley between Sparta 

 and Lockwood owes the uplifting of its beds, along the north- 

 western side, to an axis occupying longitudinally the narrow 

 primary ridgs which stretches from Sparta to Andover village. 



The dip of the limestone becomes, however, very irregular as 

 we approach the several insulated primary knobs in the vicinity 

 of Lion Pond and Panther Pond, and between these and Stan- 

 hope. Just north of Panther Pond, the little limestone which is 

 visible is seen to dip towards the northwest, evidently thrown off 

 into that position from an axis in one of these knobs. Whether 

 the axis of the Sparta ridge, that of the knob south of the pond, 

 and that traversing the ridge which passes Alamuche, belong to 

 one line of elevation, or whether, more probably, they are discon- 

 tinuous, is a point not readily settled, owing to the obscure expo- 

 sure of the limestone and gneiss, which are here much covered 

 by diluvium, and to the remarkable intricacy of the country be- 

 tween Lockwood and Andover village. 



Between Panther Pond and Lockwood. though there are pro- 

 bably several contiguous short anticlinal axes in the primary 

 knobs, including, no doubt, intervening troughs of the limestone, 

 yet this rock has been subsequently so affected by extensive 

 igneous agency in this quarter, as to show an almost total loss of 

 regularity in its dip. 



Prolonging our observations southwestward, we find in the 

 comparatively broad tract of primary rocks, which lies between 

 Lockwood and Vienna, indications of more than one axis of 

 elevation in the gneiss. The most southeastern of these has up- 

 heaved the limestone rocks of the northwestern side of the 

 Hacketstown Valley, imparting to them their present dip to the 

 southeast. This axis has probably brought to the surface, the 

 narrow tract of gneiss, extending from Hacketstown towards 



5* 



