CONTENTS 



Page 



I. Classification and arrangement 197-201 



II. Geological POSITION and geographical distribution.. . 202-227 



I. Crystalline rocks 202-213 



Granites, gneisses, syenites, norites, trap 202-207 



Limestones and marbles 207-214 



Calciferous sandrock 210 



Trenton limestone 210-2 1 1 



Niagara limestone 21 1-2 1 2 



Lower Helderberg limestone 212 



Upper Helderberg limestone 21 2-2 1 3 



Tully limestone 213 



II. Fragmental rocks — sandstones 214-227 



Potsdam sandstone 21 7-2 1 8 



Hudson river group 218 



Oneida conglomerate 218-219 



Medina sandstone 219-2*21 



Clinton group. 221 



Oriskany sandstone 221 



Caudi Galli grit and Schoharie grit 221 



Marcellus shale and Hamilton group 221-223 



Portage group 223-224 



Chemung group 224 



Catskill group 224 



Triassic formation 225-226 



