354 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



shales, sandstones, and conglomerates (counties of Herkimer, Stark, 

 &c). The shales are the most persistent, being present everywhere, 

 east and west. The last is crowned with a top layer of limestone. 



The above statement being true in the general, still this group is 

 continually varying. Its extremities, eastern and western, within the 

 limits of New York, scarcely show a detail in common, mineral or 

 fossil (Hall, Pal. ii.). The easiest way, therefore, of communicating 

 an idea of the true nature of this group will be by a series of sec- 

 tions, — the first exhibiting the Clinton in its most complete form, 

 and the others its diversities from east to west. 



Section I. 

 Above the Lower Falls of the Genessee. (In ascending order.) 



1. Green shale, resting on the grey band of the Medina Sandstone. 



2. Oolitic iron-ore, with concretions, bits of shells, corals, &c. 



3. Pentamerus-limestone, with sandy layers or chert. 



4. Green shale, paler than No. 1, with bands of limestone {Atrypa herni- 



sphcerica and Graptolites). 



5. A second iron- ore bed. 



6. Limestone similar to the more calcareous parts of No. 3. (Crinoidea.) 



Section II. 

 James Hall's most easterly section is from the town of Canojoharie, Montgo- 

 mery County, beyond the eastern limits of the Medina Sandstone and of the 

 Niagara group. 



It is as follows (from above) : — 



1. Drab-coloured layers of the Onondaga-Salt-group. 

 r 2. Coarse red sandstone, with pebbles, and containing much iron- 

 ore. 



3. A space occupied by shales. 



4. Greyish sandstone, conglomeratic below ; darker coloured and 

 ^ laminated above. 



5. Oneida Conglomerate. 

 7. Shales of the Hudson-River-group. 



Section III. 

 At Vanhornville. (From above.) 



1. Onondaga-Salt group. 



f 2. Red, coarsely-laminated, friable sandstone, with much iron-ore, 

 and not in distinct beds. 



3. Green shale, with fossils. 



4. Red, diagonally laminated sandstone. 



5. Greyish sandstone and conglomerate, with thin layers of green 

 ^ shale. 



6. Oneida Conglomerate. 



7. Shales and sandstones of the Hudson-River-group. 



Section IV. 

 In Stark Township, Montgomery County. (From above.) 



1. Onondaga-Salt group. 



2. Quartzose sandstone and conglomerate, forming the top of the Clinton 

 group. 



3. Thin-bedded sandstones, with fucoids, alternating with green shale. 



4. Red sandstone, diagonally laminated. 



5. White sandstone with pebbles, and green shale. 



6. Oneida Conglomerate. 



7. Shales of the Hudson-River-group. 



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