133 



Beneath several feet of alternating bands of lead-coloured and 

 yellowish slate, lies a very extensive bed of compact red shale, 

 in thick and solid layers. This mass has evidently been partially 

 acted on by the elevated temperature of the adjacent trap dike 

 of Long Hill to its west. 



It is traversed by natural joints, generally several feet asunder, 

 extending parallel with each other from northeast to southwest, 

 separating the whole into immense blocks and tabular masses, 

 which are readily cleft into pieces of any desirable size for 

 masonry. In many places the lamina; of the rock are somewhat 

 contorted. Towards the bottom of the quarry the material 

 acquires more of the character of a sandstone. The dip is at an 

 angle of 15° towards the west. On the same side of the Passaic, 

 about a mile above Chatham, near a mill, the sandstone is 

 again exposed to view by the erosive action of a small tributary 

 stream. 



At Lindsay's Mill, three miles southwest from JMadison, denu- 

 dation has exposed the rock in many places. It has the aspect 

 of a thinly laminated shale, with layers of a bluish and yellowish 

 slate, containing cubical crystals oi' sulphuret of iron. A yellowish 

 ferruginous sandstone is also visible in one or two spots. 



The indications at this place imply, that by removing the 

 overlying shale, a good building stone, which is much wanted 

 in this vicinity, might be procured. The dip in some places is 

 slightly irregular, being in certain spots horizontal, and again 

 being directed eastward at an angle of not more than 5°. 



A deep diluvial bed of sand and gravel covers the plain from 

 Morristown to the end of the ridge of trap, which extends north- 

 ward from Green Village by Spring Valley ; but west of this 

 outburst of trap the sandstone appears. In the vicinity of New 

 Vernon the red shale is often exposed, dipping generally at 

 about 8° to the westward. South of the last named village the 

 shale and sandstone display their ordinary features, although 

 they show in some places traces of alteration from their proxi- 

 mity to the trap. The same remarks apply to the vicinity of 

 Basking Ridge. East from this place, and northward from Long 

 Hill and Green Village, there is an extensive level tract called the 

 Great Swamp, consisting chiefly of meadow, the rocks here being 

 covered throughout by a wide deposit of diluvium. 



12 



