THE MINING AND QUARRY INDUSTRY 147 



Rome. From here the group extends northwest into Lewis and 

 Jefferson counties and then again southwest into Oswego county 

 where the formation terminates at the east end of Lake Ontario. 



The strata of this group consist of fine grained grayish 

 sandstone. They occur in even layers and most of the quarries 

 show well defined jointed structure. To the east of Schenectady 

 county, the rocks of this group are often involved in a complex series 

 of folds and faults, but to the west of the county, folds are not 

 important and the rocks of this group have a dip to the south which, 

 however, is modified by the presence of several fault planes. The 

 great extent of the group, the comparative ease with which the 

 stone may be quarried and the exceptional transportation facilities 

 have resulted in the opening of a large number of quarries. Most 

 of the quarries produce stone for local use only, while the larger 

 quarries produce stone mainly for rubble and common masonry 

 work. At present none of the large quarries are in steady operation. 



Medina sandstone. The Medina formation occupies a belt 

 averaging nearly lo miles w^ide, which extends along the southern 

 shore of Lake Ontario and projects into the Mohawk valley, where 

 the formation is represented by coarse beds of sedimentation repre- 

 senting the upper portion of the Medina and known in this section 

 of the State as the Oneida conglomerate. The conglomerate is 

 coarsest at the base and becomes more like the typical Medina sand- 

 s^tone with diagonal laminations as we pass higher in the formation. 

 In this section of the State, the passage of this formation into the 

 Clinton appears to be gradual and the division line between the 

 two formations has been as yet not clearly drawn. There are 

 quarries in the Oneida conglomerate which produce stone for local 

 use. 



In western New York, the Medina formation is 1200 feet thick. 

 All the quarries which are operated between the Niagara and the 

 Genesee rivers are in the upper 150 feet of the formation, and 

 usually but a short distance north from the Niagaran escarpment. 



The quarries operated in western New York are mostly in Orleans 

 county. The other quarries outside of this county are at Lockport 

 and Lewiston in Niagara county and at Brockport and Rochester 

 in Monroe county. In Orleans county, most of the quarries are 

 located near the banks of the Erie canal. This, together with the 

 nearness of the railroad, offers excellent shipping facilities. Some 

 of the quarries have the advantage of being located between the 

 canal and the railroad and practically occupy all the space between 

 them. 



