22 



NEW YORK STATE MUSEUM 



Fig. 3 Outline map of the Canton quadrangle to illustrate possible distribu- 

 tion of the Potsdam sandstones 



CCOOOo 



Ogdensburg 

 oolomite; 



led Potsdan 

 sandstone ; 



Heuvelton 



oolomite; I ■■■'■•■ ■"-I sandstone; lii^ 



Red Potsdam | ~~| Possible limit 

 I of Theresa; 



" White Potsdam " 

 sandstone ; 



Limit of known 

 Precambrian 



outcrops ; 



Limit of abundant Precambrian exposures 



Between these two limits there may be extensive concealed areas of the 

 Potsdam sandstones 



