KKW rOBX BTAT1 MUSEUM 



'■■ matter. Whether or not clay underlies the marl is not 



All. 



Marl also occurs on the laud of J. C. Austin, 2 miles north of 



q<3 about a foot of it u exposed in the ditch in J. D. 



I mile north of town (pi. 43, 44). So far as 



known none of this marl has thus far been utilized. The follow- 



D analysis of the material. 



lea 2.1 



Alumina ) .. ^o 



id ) 



Lime carbonate 87.1 



Magnesium carbonate 2 . 31 



loluble and organic matter 11 



Another deposit of marl is found south of Chittenango Falls. 



Monroe county 1 



The Niagara is the most prominent and extensive limestone in 

 the county, though Clinton, and Onondaga are also known. 

 Quaternary marl is likewise found. 



The Niagara limestone extends across the county as a belt 

 several miles wi<le, its northern edge passing through the towns 

 IVntield, Brighton, Ogden, Gates and Sweden. The upper 

 magne8ian member generally forms the outcrops, and the weath- 

 1 surface of the rock has a peculiar granular and spongy ap- 

 pearance. The upper member, or Guelph limestone, is a grayish 

 brown, finely crystalline limestone containing numerous small 

 = . The rock is very low in silica and has a large amount 

 of mm making it well adapted for refractory linings in 



fun The lower Led-; of Niagara limestone are hard, com- 



erally highly silicious in Monroe county. The Ni- 

 agara - mderlies the Niagara limestone, and the transitional 



sometimes furnish a natural cement rock. 

 Is of this nature outcrop at Shelby falls in the town of Barre. 



i Hall, James. Qeol. I th dist \. V. p. 422. 



