CONTENTS. 7 



PlOS. 



24. Genesee slate, Black shale of the Report, , 168 



25. Portage or Nunda group, Sherburne flags and shale of the Reports, 168 



Preliminary observations upon the upper part of the Erie division of the New- York System,. 170 



26. Ithaca group, , 174 



27. Chemung group, 179 



28. Catskill group, Montrose and Oneonta sandstone of the Reports, Old redsandstone of 



England, 186 



CHAPTER VI. 



LoKilities of the superposition of the different rocks of the preceding chapters, with the exception 



of some of the upper ones, illustrated by wood-cuts, 195 



CHAPTER Vn. 

 Uplifts in the valley of the Mohawk, and upon East and West Canada creeks, 203 



CHAPTER Vni. 



Quaternary deposits, 212 



Alluvial deposits of clay, etc 212 



— of sand, 220 



— of boulders, 220 



— of boulders of Primary rock, 321 



— of boulders or blocks of the Transition class, 223 



— of lake marl, 224 



Localities of calcareous or lake marl from the rocks,. 225 



The same, but from deposits of alluvial materials, 225 



Calcareous tufa 226 



Ferruginous tufa, 227 



Bog ore or limonite, etc 228 



Peat or muck, 229 



Soil, 231 



Mineral spring, 233 



CHAPTER IX. 



Embracing excavations or denudations, valleys; lakes; scratches upon rocks which have been 



smoothed ; and mounds, 235 



Excavations, valleys, 235 



Lakes, 237 



Otsego lake, • 238 



Schuyler's lake, 238 



Cazenovia lake, 238 



Otisco lake, 238 



Skaneateles lake, 238 



Owasco lake, 239 



