Geographical Distribution. 17 



from this formation in the southern part of Herkimer county, and at 

 Clinton and at Higginsville in Oneida county. 



Oriskany Sandstone, 



This sandstone is generally too friable to make a good building 

 stone ; and no quarries of importance are known in it. 



The sandstones of the Cauda Galli and of the Schoharie 

 Grits are either argillaceous, and therefore not durable, or too porous 

 and loosely cemented to make good building material. No doubt, 

 localities could be found where some of the beds may be compact and 

 solid, and may be quarried profitably for local use. The Marcellus 

 Shale, a more shaly formation than either of them, has furnished 

 stone for building at Chapinville in Ontario county. 



Hamilton and Portage Groups. 



The rocks of these geological groups are shales, slates and sand- 

 stones. But there is so great a range in composition and texture that 

 there are many varieties under each of these heads and an almost in- 

 finite gradation from one to another ; and no sharp lines of demarca- 

 tion or division can be drawn. And the notes on the sandstones of 

 the Hudson River group apply here also.* 



In the Hamilton group, and above it, in the Oneonta sandstone 

 in the eastern part of the State, there is a great development of 

 gray, hard, compactly aggregated sandstone, which is thin-bedded 

 or can be split on planes parallel to the bedding, and which is 

 known as flagstone. This variety predominates in the upper part 

 of the Hamilton formation, and continues into the Portage, or its 

 equivalent here — the Oneonta sandstone. In the central part of the 

 State, where this group is recognized, in a belt south of the Mohawk 

 valley, in Otsego, Chenango, Madison, Cortland, Cayuga and Seneca 

 counties, the sandstone is more or less mixed with shale and slate in 

 irregularly alternating strata. And olive, greenish and yellowish 

 shades of color prevail. In the western part of the State — that is, in 

 the belt, stretching from Seneca lake to Lake Erie — through Ontario, 

 Livingston, Genesee and Erie counties, the olive and bluish-gray shales 

 predominate, and the sandstone is not abundant nor of the best quality 

 for a building stone. 



The Portage rocks in the western part of the State have been 

 divided into shales at the base ; then shales and flagstones ; and the 

 Portage sandstone at the top. In the last division thick beds with 



*See pages 15 and 16. 



