244 
[Assembly 
in its turn cedes its place in like manner in part to the " millstone 
grit " and the protean group, causing these two latter masses to occu- 
py the southern half of the area. Whilst the green shale is extending 
itself through Oneida, other rocks appear which have no existence in 
Herkimer. These rocks commence between Utica and Rome, and co- 
ver the northern side of the area. They appear from under the " mill- 
stone grit," and from above the green shale of Herkimer, and of the 
same rock in the creek to the east of Utica, or in other words, from be- 
tween the two rocks. These rocks are the shales and green sandstone 
of Salmon river, and the red sandstone of Oswego; they cover a consi- 
derable portion of the north part of Oneida, the greater part of Oswego, 
and the red sandstone forms the triangle in the northern part of Stirling, 
in Cayuga, appearing immediately under the " grit." 
The further progress of the elevation causes in Madison, another 
change; the red shale which rests upon the protean group, adds another 
member to the area. With the exception of the curve from Rome, the 
entire length of the Erie canal in that county is excavated in the red 
shale. And the final progression of the elevation in the Third District , 
causes portions of the gypseous hills of Onondaga and Cayuga, they be- 
ing the equivalents of the water limes east of Oneida creek, to form as it 
were portions of the same plain. With the Third District, our observa- 
tions should end; but a general idea of the whole elevation is required, in 
order that the report of the salines of Onondaga should be fully under- 
stood, and all doubts as to the superposition of the rocks should be re- 
moved, which could not be, unless the whole range should be given. 
Besides it may be said, that no part of the geology of New-York, judg- 
ing from what has been written, is more obscure than the part we are 
treating, and its importance requires all the light that can be thrown 
upon it. 
Near the Cayuga lake, the rocks are at their point of greatest depres- 
sion, and from thence rise, going west. The effect of which is to cause 
all those rocks which underlie or compose the area or depression to 
again reappear as an elevation. 
Thus the red sandstone of Oswego which covers the triangle in Stir- 
ling, Cayuga, which cannot be over 15 feet above Lake Ontario, forms 
the low^er falls of Rochester, rising nearly 100 feet above that level. 
The red sandstone is followed by the gray sandstone, quarried near the 
line of the county, between Martville and Hannibal ville, and of Hulme's 
quarry in Stirling, being the " millstone grit" of Oneida, and the gray 
