76 



Description of the Champlain group, and characteristic 



fossils. 



Description of the Potsdam Sandstone. 

 " " Calciferous Sandstone. 



" " Isle La Motte Limestone. 



" " Trenton Limestone. 



" " Black Shales. 



" Dove-Colored Limestone. 



" " Red Sand-Rock Series. 



Taconic Rocks : 



Sparry Limestone, 



Taconic Slates, 



Magnesian Slates, 



Stockbridge Limestone, 



Granular Quartz. 

 Brown Iron Ore Series : 



Silicious Limestone, 



Quartz, 



Kaolin, 



Lignite. 

 Green Mountain Rocks : 



Talcose Slate, 



Clay Slate, 



Chlorite Slate, 



Green Mountain Gneiss, 



Mica Slate, 



Steatite, 



Serpentine. 

 Calcareo-Mica Slate Formation : 



Clay Slate, 



Silicious Limestone, 



Mica Slate, 



Hornblende Slate, 



Silicious Slate, 



Gneiss. 

 Igneous Rocks : 



Granite, 



Trap, 



Porphyry, 



Feldspar, 



Quartz. 



