2l8 BULLETIN OF THE NEW YORK STATE MUSEUM 



The Hammond quarries produce a gray to red stone, 

 nearly all of whose output is cut into paving blocks and 

 street material. 



Hudson River Group 



The rocks of this group crop out in Orange county, 

 north-west of the Highlands and in the valley of the Hud- 

 son river northward to the Champlain valley in Washing- 

 ton county. From the Hudson westward the Mohawk 

 valley is partly occupied by them. The belt increases in 

 breadth, thence in a north-west course across Oneida, 

 Oswego and Lewis counties, and continues to Lake Ontario. 



The rocks consist of shales and slates, sandstones and 

 siliceous conglomerates. The slates are noticed under the 

 heading slates, and in the notes on quarry districts. 



The sandstones are generally fine-grained and of light 

 gray or greenish-gray color. They are often argillaceous and 

 not adapted for building purposes. But the even-bedded 

 and well-marked jointed structure makes the quarrying 

 comparatively easy, and the nearness to lines of transporta- 

 tion, and to the cities of the Hudson and Mohawk valleys 

 have stimulated the opening of quarries at many points. 



For common rubble work* and for local uses the quarries 

 in this formation have furnished a large amount of stone. 

 The more important quarrying centers are now at Rhine- 

 cliff on the Hudson, New Baltimore and Troy, in the 

 Hudson valley ; at Aqueduct, Schenectady and Duanes- 

 burgh, Schenectady county; Frankfort Hill, Oneida county; 

 and in the town of Orwell, Otsego county. 



These quarries have a local market and do not supply 

 much, if any, stone, to distant points. And 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. 



*Prof. Amos Eaton gave the name- of "rubble stone " to the sandstone in the upper 

 part of the formation. ♦ 



