THE MINING AND QUARRY INDUSTRY I9I4 63 



several miles wide, from Niagara Falls east to Onondaga county 

 and then with diminishing width across Madison county. The up- 

 per layers are rather heavy and yield material suitable for building 

 purposes, road metal and lime. There are quarries around Niagara 

 Falls, Lockport and Rochester. It is worked to some extent in 

 Wayne, Onondaga and Madison counties. The Guelph, also a 

 dolomite, occupies a limited area in Monroe and Orleans counties 

 and is worked near Rochester. 



The Cayugan group includes among its members the Cobleskill, 

 Rondout and Manlius limestones, which are economically important. 

 They have furnished large quantities of material for the manufac- 

 ture of natural cement, being the source of the cement rock in the 

 Rosendale district and in Schoharie and Onondaga counties. The 

 cement rock of Erie county is found in the Salina formation. The 

 Manlius limestone is used for portland cement in the eastern part 

 of the State. 



At the base of the Devonic system appears the Helderbergian 

 group which is very important for its calcareous strata. Lime- 

 stones of this age are strongly developed along the Hudson river in 

 Albany, Columbia, Greene and Ulster counties. The Coeymans or 

 lower Pentamerus and the Becraft or upper Pentamerus limestones 

 afford material for building, road metal, lime and portland cement. 

 The limestone for the portland cement works at Hudson and Green- 

 port is obtained from Becraft mountain, an isolated area of lime- 

 stones belonging to the Manlius, Helderbergian and Onondaga 

 formations. The works at Howes Cave use both the Manlius and 

 Coeymans limestones. Extensive quarries are lo:ated also at Cats- 

 kill, Rondout and South Bethlehem. 



The Onondaga limestone, separated from the preceding by the 

 Oriskany sandstone, has a very wide distribution, outcropping al- 

 most continuously from Buffalo, Erie, county, eastward to Oneida 

 county and then southeasterly into Albany county, where the belt 

 curves to the south and continues through Greene, Ulster and 

 Orange counties to the Delaware river. It is in most places a bluish 

 gray, massive limestone with layers and disseminated nodules of 

 chert. The chert is usually more abundant in the upper beds. The 

 limestone finds use as building stone and the less siliceous materials 

 also, for lime-making. Quarries have been opened at Kingston, 

 Split Rock (near Syracuse), Auburn, Waterloo, Seneca Falls, Le 

 Roy, Buffalo and other places. 



The Tully is the uppermost of the important limestone formations 

 and likewise the most southerly one represented in the central part 



