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NEW YORK STATE MUSEUM 



however, to restrict the market for Potsdam sandstone notwith- 

 standing its excellent qualities. 



Hudson river sandstone. The Hudson river series which was 

 once assigned a definite position in the geologic scale is now recog- 

 nized to be a complex of beds ranging from middle Trenton to 

 Lorraine age. Inasmuch as the various horizons have not been 

 delimited yet on the map, the name may be conveniently retained 

 in its former areal significance. 



The rocksTbelonging to this group are found in the Hudson river 

 valley from the Highlands northward to Glens Falls and along 

 the Mohawk to Oneida county whence they extend around the 

 western Adirondacks through Lewis into Jefferson and Oswego 

 counties. Shales, slates, sandstones and conglomerates are repre- 

 sented. The sandstones are usually thinly bedded, argillaceous 

 and of grayish color. They have little importance except for local 

 markets and their use is mostly limited to rubble and common 

 masonry work. No large quarries supplying this stone are in 

 steady operation at present. 



Medina sandstone. The Medina formation comprises a great 

 thickness of sandstones extending in a wide belt from the central part 

 of Oneida county westward along the border of Lake Ontario to 

 Niagara river. A smaller area outcrops in Orange and Ulster 

 counties. The stone is usually gray, red or mottled in color with 

 medium to coarse texture. It shows fair crushing strength and is 

 an attractive building stone. The quartz grains are partially 

 replaced at times by decomposed feldspar but seldom in such an 

 amount as to injure the quality of the stone. 



The flat, even bedding and the regular jointing which usually 

 characterize the Medina, facilitate its working, while its occurrence 

 in a populous district has promoted the growth of a large quarrying 

 industry. The most productive field of operations lies on the 

 southern edge of the belt and extends from Brockport, Monroe co., 

 through Holley, Hulberton, Hindsburg, Albion, Eagle Harbor, 

 Medina and Shelby Basin, Orleans co., to Lockport and Lewiston, 

 Niagara co. Albion, Hulberton and Medina are the chief quarrying 

 centers at present. The quarries are well equipped and their 

 combined capacity largely exceeds the output. There is a wide 

 demand for the stone as .building material, though the market has 

 been curtailed to some extent in recent years by active competition 

 with the Berea sandstone of Ohio. It finds employment also 

 for curbing and flagging and specially for paving blocks for which 

 purpose it takes the place of granite and trap. 



