MEDINA SANDSTONE. 
143 
Again, in Cayuga county, the Medina sandstone appears in the north part. At Stirling 
centre, the exposed rock is about twenty-five feet thick. It appears at Martville, where 
it is of two kinds : a hard and variegated mass, with diagonal cleavage planes ; and a 
coarse friable rock, of a color darker than the preceding. 
In Wayne county, at Wolcott furnace, and on Salmon creek about two miles northeast 
of the furnace, this rock appears in a ravine. It is also quarried on Beard’s and Little 
Red creeks, for building and for hearth-stones. Still farther west, in Monroe county, it 
appears on the lake shore in the town of Penfield. At the lower falls of the Genesee 
river, it is exposed for more than one hundred feet. At Medina, on Oakorchard creek, 
the rock is still better exposed and characterized than at any of the places which I have 
named. It is better, not because it is thicker, but because there is a better exposure of its 
fossils than elsewhere. 
From Medina to Lockport, the harder part of this rock crops out near the line of the 
canal, or in a terrace which is formed by its protrusion. At the latter place, about one 
mile below the village, on Eigliteen-mile creek, it exhibits the same characters as at the 
former place. Proceeding from Lockport to Lewiston, it is found forming a part of the 
slope of the terrace, and contributes principally to its height by the resistance which the 
hard middle portion has offered to the weather ; while the lower portion, hy its rapid 
change when exposed to the weather, and consequently by its destructibility, gives a more 
depressed surface to the country under which it lies. At Lewiston, it forms the banks of 
Niagara river, where it is exposed for two hundred feet. It extends towards the lake, but 
gradually slopes to its level, and disappears beneath the superincumbent clay. 
Thickness. This rock is thin in Oswego and Lewis counties, but thicker as it extends 
westward, as we have already observed. It swells to the thickness of two hundred feet 
upon the banks of the Niagara river. On this river, too, it is more expanded than to the 
eastward. The entire thickness of the rock, as determined by the survey of Mr. Hall, 
upon this river, is not less than three hundred and fifty feet. The increase in thickness at 
Lockport and Niagara, over that of Oswego, is due to additions which were made to the 
inferior and softer portion of the rock. At Oswego and vicinity the rock is generally 
hard, and destitute of those softer and argillaceous parts which are so important in the 
western districts just referred to. 
Agricultural characters of the Medina sandstone. The softer parts of this rock decompose, 
and form an excellent wheat soil ; but its peculiar properties will be given in another part 
of this treatise. It is only west of Oswego county, where the rock is adapted by its nature 
to form a soil suitable to the growth of this grain. 
Surface of the country over which this rock prevails. Two causes conspire to create a level 
country, through which this rock passes : 1, a freedom from igneous action ; and, 2, even¬ 
ness of composition in the rock itself, which secures a uniformity of action so far as at¬ 
mospheric agents are concerned. The hard belt of reddish gray sandstone between Medina 
and Niagara forms an elevated platform, but the country is by no means broken into 
