LIME AND CEMENT INDUSTRIES 807 



* 



become argillaceous. Cherty layers are sometimes common in the 

 upper part of the formation. 



The chief value of the Corniferous is as a building stone, 

 though many portions of it are adapted to the manufacture of 

 lime. Many quarries have been opened in it, and the largest 

 now in operation is at the Indian reservation in the Onondaga 

 valley. 



The Onondaga group of limestones has a total thickness of 60 

 feet at the eastern edge and 70 feet at the western edge. The 

 Corniferous is usually found at the top of the Helderberg escarp- 

 ment. At Green lakes, 2 miles north of Jamesville, 25 feet of 

 Onondaga stone is exposed. At the Splitrock quarries about 12 

 feet of Corniferous is exposed in the southwest corner, and in 

 A. E. Alvord's quarry, \ mile east of Manlius, 17 feet 6 inches is 

 exposed. Maylie's quarry, \ mile southeast of Marcellus, shows 

 the upper layers of the Corniferous, and they are also to be seen 

 in John Clancy's and M. Hogan's quarry near there. Maylie's 

 stone is used in part for lime. 



Marl abounds 1 in many of the small lakes around Dewitt and 

 Manlius. Cicero swamp is underlain by an extensive deposit, and 

 the marshes near Dewitt and Manlius also contain it. Other beds 

 are in Camillus, Elbridge and southern part of Van Buren near 

 the Erie canal. 



Two important Portland cement plants, the one at Jordan, the 

 other at Warner utilize this material. 



They are described in another portion of the report. 



Ontario county 2 



The Lower and Upper Helderberg cross the county, the north- 

 ern boundary of the belt coinciding approximately with the 



1 Luther, D. D. Economic geology of Onondaga county, (see 15th an. rep't 

 N. Y. state geol. p. 237) 



2 Clarke, J. M. Brief outline of the geological succession in Ontario county, 

 N". Y. {see 4th an. rep't N. Y. state geol.) 



Hall, James. Geol. 4th dist. N. Y. p. 453. 



