Plate I 



Upper figure. Photomicrograph; enlargement 30 diameters, nicols crossed. 

 Typical Grenville limestone, purer phase. Calcite grains show abundant 

 twinning lamellae or pressure bands ; subordinate megascopic coccolite and 

 graphite, and microscopic scapolite. 



Stevens's quarry, 3.5 miles south of Canton village bench mark. 



Lower figure. Photomicrograph ; enlargement 30 diameters, nicols crossed. 

 Typical Grenville limestone, silicate phase. Calcite subordinate ; phlogopite 

 and feldspar predominant. 



Crary Mills, south corner of Potsdam township. 



