SANDSTONES 385 



These quarries have a local market and do not supply much, 

 if any, stone to distant points. Nearly all of the stone is used in 

 foundation and common wall work. 



Oneida Conglomerate. 



This formation is developed to its greatest thickness in the 

 Shawangunk mountain in Orange and Ulster counties. 



It is recognized in the Belle vale and Skunnemunk mountains, ■ 

 also, in Orange county. In the central part of the State.it is 

 traced westward in a narrow belt from Herkimer county into 

 Oneida county. The prevailing rocks are gray and reddish-gray, 

 silicious conglomerates and sandstones, which are noted for their 

 hardness and durability. The cementing material is silicious. 

 The jagged edges and angular blocks and the polished and 

 grooved surfaces of the glaciated ledges, so common on the 

 Shawangunk range, afford the best proof of the durable nature 

 of these rocks. The bottom beds, near the slate, contain some 

 pyrite. No attempt has been made to open quarries for stone, 

 excepting at a few localities for occasional use in common wall 

 work. The grit rock is quarried near Esopus Creek for mill- 

 stones. 



The accessibility of the outcrops to the New York, Lake Erie ' 

 and Western railroad, the New York, Ontario and Western rail- 

 road, the West Shore railroad and the Delaware and Hudson 

 Canal lines is an advantage, as well as the comparative nearness 

 to New York. And no other formation in the State exhibits in 

 its outcrops better evidence of ability to resist weathering agents- 



Medina Sandstone. 



The Medina sandstone is next above the Oneida conglomerate. 

 It is recognized in the red and gray sandstones and the red and 

 mottled (red and green) shales of the Shawangunk and Skunne- 

 munk mountains in Orange county. A large amount of the red 

 sandstone has been quarried on the north end of the Skunnemunk 

 range, in the town of Cornwall, for bridge work on the railroads 

 which cross the range near the quarry. 



The red sandstone is seen exposed in the cuts of the Erie rail- 

 way northeast of Port Jervis. This formation reappears in 



