148 
ONTARIO DIVISION. 
within two miles of the lake shore, and where it can not be less than fifteen or twenty 
miles wide. This, too, is the most important part of the series, as the iron ore beds are 
better developed than either east or west. At Rochester, the series is about eight miles 
wide, which width it retains to the Niagara river. It crosses the Genesee below Rochester, 
and forms the little ridge on the north side of the canal, or a low terrace which runs nearly 
parallel with it. The canal soon intersects this ridge, whence it then extends on its south 
side to within eight or nine miles east of Lockport. From Lockport it forms a sort of slope 
or terrace, which extends to Niagara river. 
Oneida lake, and the low marshy grounds in Cicero, are excavated in this group. Its 
distribution, and the width of the formation, together with the course of the southern 
boundary, may be seen by an examination of the map : the belt is colored green. 
Relations of the Clinton group. To the eastward this group is superimposed upon the 
Oneida conglomerate. The disappearance of this mass, as the series extends westward, 
seems to alter or change its relations ; for instead of passing beneath the Medina sand¬ 
stone, which it meets in the northern part of Oneida county, it takes a position superior to 
it, and hence the Medina sandstone becomes the supporting mass or base throughout its 
whole distance to the Niagara river. Superiorly the group is merged in a shaly sandstone, 
which, if it does not coalesce with the more perfect, limestone called the Niagara, still does 
not disappear abruptly and form a strong and well marked line of demarkation with it. 
The relations of this group, then, are by no means obscure on the route I have described. 
We should expect, however, from so perfect a development of a series within this section 
of the State, that it would also appear within its bounds wherever the inferior and superior 
rocks are found ; but this is not the case. Thus in the valley of the Rondout, the Oneida 
conglomerate forms an important rock, and ought to be succeeded by the Clinton group j 
but instead of this being the case, it is wanting. The relations of the rocks of this part of 
the State are represented on PI. XX. Section 3 : see also the same plate, section 2, which 
extends across the valley of the Schoharie creek. The same absence of this group will be 
noticed in the section at Cherryvalley, still farther west, on the main sectional route from 
Albany to Auburn. It is only, therefore, in the direction and vicinity of the Erie canal, 
that we are to look for this series ; parallel with which, it extends across the State, from 
near the eastern bounds of Springfield or Warren in Herkimer county, to the Niagara river. 
Contour of the country over which the Clinton group extends. The most level and unin¬ 
teresting part of the State, is that which is underlaid by the Clinton group. To be satisfied 
of the truth of this statement, it is only necessary to pass over the level and swampy lands 
about Oneida lake, and the Cicero swamps. The long levels of the canals, too, extend 
over this series. There is, however, some interest in the scenery of the deep gorges : 
thus, at Cruger’s in Herkimer county, but especially in the deeper and wider gorges of the 
Genesee and Niagara rivers, the scenery is imposing ; but in consequence of the absence of 
disturbances in this rock, the surface above it is invariably dull and monotonous. If, how¬ 
ever, this section of the State rises at all into ridges, they are not all connected with this 
