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the northwest is very gentle, though considerably greater than it 

 seems to be from looking at the face of that precipitous escarp- 

 ment, the line of which is not sufficiently in the direction of 

 the dip to make the full degree of inclination apparent. The chief 

 part of the beds in this portion of the series are apparently arena- 

 ceous enough to furnish a very good sandstone for the ordinary 

 purposes of architecture. 



In other parts of their range, these beds, lying immediately 

 below the conglomerate, are generally of the composition exhi- 

 bited near the Delaware. Near Pompton, however, where the 

 very top only of the series is exposed, the red sandstone and shale 

 occur in somewhat different features. In a quarry near that 

 place, the red sandstone may be seen of its ordinary character, 

 alternating in thin beds with a very heterogeneous fine-grained 

 conglomerate, made up of a great variety of materials, and pre- 

 senting, as it were, a miniature of the variegated conglomerate 

 above it. These sandstones are parted by very thin layers of the 

 soft shale, almost in the state of a compressed red clay. At the 

 dividing surface of the harder and softer layers, may frequently 

 be found organic impressions of a class evidently belonging to 

 some of the older aquatic tribes of the vegetable kingdom, appa- 

 rently fucoides. 



Upon these sandstones there rests a thin bed of a gray siliceous 

 slate, very schistose, though of too coarse a texture to warrant 

 its being usefully applied. Besides the sand in its composition, 

 there is a moderate proportion of mica. Its laminae coincide with 

 the planes of stratification ; the thickness of the whole mass is in- 

 conderable. The variegated conglomerate of this neighbourhood 

 rests in a conformable position upon this slate. All these rocks 

 dip to the northwest. 



Having in the foregoing sketch described the several subordi- 

 nate members of the red sandstone formation, as we find them 

 developed along the valley of the Delaware, both in their ordinary 

 condition and in tlieir more or less altered state as affected by the 

 neighbouring trap, let us in the next place follow some of the 

 more continuous of these, in their range across the State towards 

 the New York line. In consequence of the modification of tex- 

 ture which some of these rocks have received, by the nume- 

 rous outbursts of trap, by which the northwestern half of the 



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