824 NEW YOEK STATE MUSEUM 



There are two cement beds in tlie Whiteport-E-osendale region. 

 The lower one of these averages 21 feet in thickness, and the 

 other averages 12 feet in thickness, with an intervening mem- 

 ber of 12 or 15 feet of Avaterlime beds, but these thicknesses are 

 very variable. At High falls the upper bed is 15 feet thick, the 

 lower bed 5 feet thick with 3 feet of intervening beds of water- 

 lime rock. The High falls are over the thicker beds. 



Darton also states that ^' cement may be looked for in the 



upper Rondont valley, from Port Jackson to Ellenville, but, 



owing to the absence of outcrops, this should only be regarded a3 



V 



a suggestion. 



Around Rosendale the cement industry is developed to an 

 enormous extent, many thousand barrels of cement being 

 produced annually. Detailed mention of the cement manufacture 

 is made in another chapter of the report. 



^N^othing more will be said in this part of the report concern- 

 ing the Eosendale cement rock, as it is mentioned more fully iu 

 the chapter on natural cements. 



Coralline or [N^iagara limestone forms a thin bed underlying 

 the cement at Rondout. It is a dark gray limestone of variable 

 thickness. Under the cement at Rondout it is 7 feet, but at the 

 entrance to the Becraft limestone quarries 1 mile north of East 

 Kingston it is only 5 inches. 



Warren county^ 



Both the Oalciferous and Trenton are known in this county. 

 The former is not of very great importance except for building 

 purposes, but the latter is very prominent. 



At Glens Falls, the Trenton limestone (pi. 72) has been quarried 

 for a number of years for lime manufacture, and the product 

 bears an excellent reputation. There are four companies operating 

 lime quarries, but the rock in all of them is very much the same. 

 The section in the quarry beginning at the top consists of: 



Feet 



Thin bedded, impure black limestone 12-15 



Massive black limestone 2-3 



Fine grained, black, crystalline limestone 15 



1 Emmons, Ebenezer. Geol. 2d dist. N. Y. 1842. p. 170. 



