CLINTON GROUP. 



15 



CLINTON GROUP. 



'This group presents a very variable assemblage of organic remains ; resulting, as before stated, 

 from the varying conditions under ■which the strata were deposited, and from the sudden transi- 

 tions in the nature of the sedimentary deposits of which it is composed. The totality of its organic 

 Contents in its eastern and central portions, when compared with those of its western extension, 

 offer but little similarity. Marine plants are the predominating fossils of its eastern and central 

 exposures, while scarcely more than a single species of these extends westward beyond the 

 eastern part of Wayne county. The Brachiopoda, so characteristic of its western extension, are 

 rare to the east of Wayne county. The Pentamerus oblongus associated with the iron ore beds is 

 almost the only fossil which continues constant from its eastern development as far as the western 

 part of Monroe county^ These ore beds which are so distinguishing a feature of the group in 

 its eastern localities, form one of its characteristic features as far west as the Genesee liver. 



The following sections show the order of succession, and the nature of the materials of which 

 the group is composed, at different localities, from its more easterly exposures, to the Niagara 

 river : 



The most easterly section I have been able to observe, is one in the town of Canajoharie, 

 Montgomery county ; though the succession is there very obscure, and the whole thickness less 

 than fifty feeti 



1. Drab-colored layers of Onondaga-salt groupj 



2. A red coarse sandstone (forming a terrace) with pebbles, and containing much iron ore. •\ 



3. A space occupied by shales. > Clinton group. 



4. Greyish sandstone, conglomeritic below, and darker colored and laminated above. 5 



5. Oneida conglomerate^ 



Gv Shales of Hudson-river group. 



At Vanhornsville in the town of Stark, Herkimer county, the following section is exposed, 

 though somewhat obscurely. 



1. Onondaga-salt group. 



2. Red, coarsely laminated, friable sandstone, containing much iron ore, but no distinct beds, ' 



3. Green shale with fossils. 



4. Red, diagonally laminated sandstone. ^ Clinton gr. 



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



6. Oneida conglomerate. 



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



Section above Wicks's Store, in the town of StarJc, Montgomery county. 



1. Onondaga-salt group. 



2. Quartzose sandstone & conglomerate, forming the terminating mass of the Clinton group. 1 



3. Thinbedded sandstone with fucoids, alternating with green shale. 



4. Red sandstone, diagonally laminated. }• Clinton or. 



5. White sandstone with pebbles, and green shale.- I 



6. Oneida conglomerate. 



1. Shales of Hudson-river grou'p. 



