224 BULLETIN OF THE NEW YORK STATE MUSEUM 



Lake Erie.^ And the formation Is capable of supplying 

 an immense amount of good building stone and flagging 

 stone throughout its undeveloped territory. 



Chemung Group 



The rocks of the Chemung group crop out In the southern 

 tier of counties, from Lake Erie eastward to the Susque- 

 hanna. The shales are in excess of the sandstones In many 

 outcrops, and there Is less good building stone than in the 

 Portage horizon. The variation in color and texture Is 

 necessarily great In the extensive area occupied by the Che- 

 mung rocks, but the sandstones can be described as thin- 

 bedded, generally intercalated with shaly strata, and of a 

 light-gray color, often with a tinge of green or olive-colored. 

 The outcropping ledges weather to a brownish color.f 

 Owing to the shaly nature of much of the sandstone of the 

 Chemung group, the selection of stone demands care, and 

 the location of quarries where good stone may be found Is 

 attended with the outlay of time and money, and with great 

 chances of possible failures. Quarries have been opened 

 near towns and where there Is a market for ordinary grades 

 of common wall stone, and also for cut stone, but the larger 

 part of their product is put into retaining walls. At El- 

 mira and Corning good stone has been obtained, which Is 

 expensive to dress, and does not compete for fine work with 

 sandstones from districts outside of the state. The quar- 

 ries at Waverly, Owego, Elmira and Corning, and nearly 

 all of the quarries In Allegany, Cattaraugus and Chautauqua 

 counties are in the Chemung sandstone. 



Catskill Group 



As implied in the name, this formation is developed in 

 the Catskill mountain plateau In the south-eastern part of 

 the state. Sandstones and siliceous conglomerates predom- 



* Report of Prof. Hall above cited, pp. 238-9. 



f Prof. Hall's report on Fourth District (cited above), pp. 251, 252. 



