78 AN INTERESTING GEOLOGICAL LOCALITY. 



up with the ore in the same condition. The limestone 

 makes but indifferent lime. The distinctive fossil of 

 this rock is the encrinite, although it contains many 

 others." (Horton's Kept., 1839, p. 151.) 



Prof. Mather, (Geol. Kept, first district of N. Y., p. 

 362,) says of the red sandstone of Cold Hill, "Prof. H. 

 D. Rogers is doubtful about the geological age of this 

 formation, but he inclines to the opinion that it is equiva- 

 lent to the sandstones of the middle secondary, (new red 

 or triassic sandstone) which are associated with the trap- 

 pea n rocks in New Jersey and New York. The observa- 

 tions on the geological survey of the first district of New 

 York do not quite demonstrate the age of this rock, but 

 if the red slates and grits on the east side of the Hudson, 

 which are the same as those of Pine Hill in Cornwall, 

 Orange county, are the same as those of the Bellvale 

 mountain near Long Pond, and the Green Pond moun- 

 tain, which they strongly resemble, and of which they 

 appear to be an extension, they are older than the mid- 

 dle secondary sandstone (new red sandstone) of New 

 Jersey, to which Prof. Rogers refers them, and are 

 probably the geological equivalents of, and, in fact, iden- 

 tical with, the red rocks overlying and interstratified 

 with the upper part of the Shawangunk grit. 



At Townsend's iron mine in Cornwall, the decomposed 

 "delthyris shales," (Catskill shaly limestone,) "with 

 their characteristic fossils, (one of the members of the 

 Helderberg division,) are seen, and the red slates of the 

 formation under consideration adjacent, and a coarse 

 pebble rock, sometimes white, sometimes red like the 

 Shawangunk grit, also near at hand in a nearly vertical 

 position. This locality is a mile or two northeast of the 

 the northeast point of Skunnemunk mountain in Corn- 

 wall, Orange county." 



Here Prof. Mather speaks of the uniform, nearly ver- 

 tical dip of all these red and grit rocks in the counties of 



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