CLAYS or NEW YOEK 675 



Ontario east of Lewiston; on Oashaqua creek^ deposits of tenacious 

 clay due to tlie crumbling of the argillaceous green shales. In 

 Magara co.^ beds of clay are said to occur in every town, but 

 they often contain a considerable amount of lime. 



A bed of blue and red clay is being worked at Brighton near 

 Eochester. This deposit lies near the head of Irondequoit bay 

 and was deposited by some stream flowing into it. To the southeast 

 of Rochester is a large eskar which extends in a northeast direction 

 to near Brighton. Mr Upham, who has described this eskar, con- 

 siders that it was formed by a river which flowed between walls of 

 ice and deposited the bed of clay above mentioned.^ 



Clays are also found at several points in the valley of the Oswego 

 river from Syracuse to Oswego, an important one being at Three 

 Kiver point. 



An extensive bed of red and gray clay, 20 acres in extent and 

 horizontally stratified, occurs at Watertown. The deposit is 20 feet 

 thick and rests on Trenton limestone. 



Another deposit of considerable size is being worked at Ogdens- 

 burg. The clay is blue and has a depth of 60 feet. 



At Madrid, in St Lawrence co., is a small deposit, probably the 

 remnant of a formerly extensive one. The section is: 



Yellow stratified sand , , 3 feet 



Blue clay with shells 1 " 



Blue clay 20 " 



Total thickness 24 " 



The shells are probably M a c o m a f u s c a Adams 



Turning our attention to the southern portion of the state we 

 find clays in abundance, in all the valleys and lowlands, the exten- 



1 Oeol. New York, 4th district. 1843. p. 227. 



2 " p. 444. 

 s Roch. acad. sci. proc, 2: 181. 



