MINERAL RESOURCES OF THE STATE OF NEW YORK 



267 



measures 60 feet in places. In the vicinity of Syracuse the lower 

 pure beds, locally known as the " gray limestone," have a thickness 

 of 10 to 30 feet; it is extensively worked for building stone, and is 

 recognized as a strong, durable material of attractive appearance. 

 The Split Rock quarries near Syracuse which formerly supplied the 

 limestone used by the Solvay Process Co. partly lie in this layer. 

 The principal building stone quarries in the gray limestone are on 

 the Onondaga reservation, 6 miles south of Syracuse. The Onon- 

 daga limestone as exposed in Albany and Greene counties is repre- 

 sented chiefly by the cherty member and is not quarried to any 

 extent. In Ulster county, southwest of Kingston, are a number 

 of quarries which have employed the stone for lime manufacture. 



The Tully limestone is confined to the central part of the State. 

 It seldom measures more than 20 feet thick, but has considerable 

 importance for quarry purposes, as it is the only available limestone 

 in the particular section in which it outcrops. Its western limit is 

 in the town of Gorham, Ontario county, whence it follows a winding 

 course southeast to Seneca lake under the depression of which it 

 makes a long loop to the south. It crosses Seneca county to the 

 vicinity of Cayuga lake, of which it parallels the shore for 15 miles 

 on either side, passing under the lake just north of Ithaca. The 

 outcrop then continues across the south end of Owasco lake and 

 of Skaneateles lake, runs across southern Onondaga county and 

 comes to an end in the town of Smyrna, Chenango county. The 

 limestone is low in magnesia, but contains considerable argillaceous 

 matter. It is the basis of portland cement manufacture at Portland 

 Point on Cayuga lake and is employed for local needs of crushed 

 stone and foundation stone at various places along the outcrop. 



Analyses of Devonian limestones 



Si02... 

 AI2O3 . . 

 FejOs. . 

 MgO. . . 

 MgCOs 

 CaO . . . 

 CaCOs. 

 CO2... 



3-87 

 1.07 



1-34 



tr 



5411 

 40.6 



71 

 2.5 

 1,65 



tr 



45.22 

 39-1 



2-75 



1-5 



1.6 



53 I 

 42. 1 



4 



34 





54 



I 



03 





19 



52 



13 







2.52 



} .98 



■37 

 53 23 



2.67 



1 .23 



.96 



53-26 



I 



51 



84 

 63 



82 

 23 



40 



512 



1-45 



•74 



2.93 



48.34 

 41 .22 



