MADISON COUNTY. 
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sandstone, but variable, which is hard, yellowish, greenish and blackish, with a few of its 
usual fossils. Under the Oriskany sandstone there is a dark fetid limestone, which appears 
to belong to the Pentamerus limestone. It contains fossils, but those obtained were in frag¬ 
ments, and their kind not satisfactorily ascertained. It is quite a thin mass, not much over 
a foot thick. Under it are layers of the Water-lime group, which extend to the bottom of 
the falls. The falls are said to be one hundred and thirty feet in height. At about a third of 
the height from the top, there is a shelf which projects from the base, below which is a 
thick layer with oblique divisions ; under which is a much thicker one, composed of thin 
straight courses, followed by another of like size with irregular divisions ; this latter extends 
to the bottom of the falls. In this lower part the Orthis plicata is quite numerous. 
The creek above the falls flows from the south, through a small handsome valley; its 
lower sides are formed of the Marcellus shales, whilst the top of the hills on both sides con¬ 
sist of the Hamilton group. 
The Onondaga limestone is quarried for door frames, and other hewn work, on the east 
side of the creek below the falls. On the west side much more is exposed, the road passing 
over its surface at the top of the hill, and extending down the creek to near Chittenango. 
Between the creek and the limestone quarry to the south of the village, this rock and the 
Water-lime group show a clilf, which is partly concealed by forest trees. At the quarry are 
the two layers of water-lime, which are burnt for cement. The top of the Water-lime group 
is covered with the Onondaga limestone ; at the bottom of which, in a few points, are some 
grains of sand, and a few black nodules which belong to the Oriskany sandstone, with nothing 
else intervening. As the cliff here can be well examined, it is evident that all the rocks 
which at the east are intermediate to the sandstone and the Water-lime group, have come to 
their end. 
The best exposition of the Marcellus shales, being the mass which rests upon the limestone 
ridge, is at the falls on Oneida creek, extending from Foster’s grist-mill to the saw-mill, 
where are also two excavations for coal. The shale is seen in numerous other places along 
its line, which in a few points approaches near the edge of the limestone ridge. At Sage’s, 
south of Chittenango village, the mass is well seen, but not much of its interior, facing the 
hill upon which the Hamilton group rests, and which extends south: at this place also a 
boring was made for coal. More of the interior of the mass may be seen on the farm of 
Peter Robertson, showing the imperfect layers of the lower part, some of which approach to 
septaria. 
Where the shales rest upon the limestone, between the quarry back of Chittenango and the 
road to Eagle, there is a spring of water about twenty feet over, and of considerable depth; 
the water enters and disappears by unknown cavities, and it appears to be a sink-hole. 
The Hamilton group covers about one half of the county, and, as usual with all those over- 
lying rocks on the south side of the Limestone range, it forms the surface mass of the whole 
of Brookfield, excepting a small projection of the Ithaca group at the southwest end; of all 
Hamilton, Madison, the east half of Lebanon, three-fourths of Eaton, the south part of New- 
