99 



Except the highly useful article just alluded to, the formation 

 described would appear not to present us with materials of much 

 interest, as respects their economical applications. 



Of iron ores, this formation has been found to exhibit very few 

 indications in New Jersey, while of other minerals either useful 

 or curious, it would seem to be equally destitute. 



Some of its less argillaceous sandstone beds appear adapted 

 to the ordinary purposes of a building stone, but care is requisite 

 in the selection, as too large a share of argillaceous matter leads 

 to a dissolution of the rock by the frost. 



The soil over this formation is usually rather meagre and of 

 inferior fertility, yet it is susceptible of remarkable amelioration 

 from the application of lime, which throughout the whole length 

 of the Kittatinny Valley, may be procured at a distance rarely 

 exceeding four or five miles from the remotest parts of the slate 

 districts. 



Gray Sandstone of the Kittatinny Mountain, Formation IV. 



Geographical Range of the Formation. — Resting immediately 

 upon the great slate stratum above described, with a conformable 

 northwestern dip, there is a thick series of hard and n)assive 

 gray sandstones, occasionally having the coarseness of a quartzose 

 conglomerate. These rocks are confined to the long, narrow, and 

 nearly straight mountain ridge, remarkable for its steep flanks 

 and almost perfectly level summit, called the Kittatinny or Blue 

 Mountain, which crosses the counties of Warren and Sussex from 

 the Delaware Water Gap, to near Carpenter's Point, but which, 

 in the form of a nearly continuous mountain, reaches from within 

 a few miles of the Hudson, near Kingston, to Cumberland county, 

 in Pennsylvania. 



Unlike the somewhat gradual transition witnessed between the 

 slate and its subjacent limestone, the passage from the slate, which 

 occupies the lower half of the eastern slope of the mountain, to 

 this overlying sandstone, is abrupt and every where well marked. 

 Cropping out in many places in a bold and rugged escarpment 

 along the upper part of the southeastern side, it forms the rough 

 but level summit of the ridge, and usually about one half of its 

 northwestern slope. 



The relative position of this gray sandstone to the overlying 



