502 
GEOLOGY OF THE FOURTH DISTRICT. 
This conglomerate, which, so far as I could discover, is identical with the outliers of a simi¬ 
lar mass in the southern part of New-York, is the fundamental rock of the great Coal forma¬ 
tion throughout the greater part of the western country, appearing everywhere, either as a 
coarse sandstone or a pebbly mass, and affording an unerring guide to the proximity of coal. 
Some portions of the mass at Cuyahoga falls are destitute of pebbles, and furnish a fine red¬ 
dish or brownish sandstone, used for building. The greater part, however, is composed of 
coarse materials, with white quartz pebbles. This character is exhibited in great perfection 
along the road from Stow to Cuyahoga falls, and in the vicinity of the former village. Just 
below the falls, its junction with the shales and sandstones of the next group is well exhibited. 
In the lower part of the conglomerate, at this place, my friend, Mr. Newberry, has obtained 
a large number of fossil plants, with the fruit of several species. They are imbedded in a 
friable brown sandstone, highly stained by iron, and though mostly casts, are in a state of 
good preservation. I afterwards obtained some similar fossils, from conglomerate near Deer 
creek, below Leavenworth, Indiana. 
Although usually destitute of fossils, this conglomerate possesses some characteristic marks 
which may serve to distinguish it at very distant points. Among these, in New-York, are 
thin seams, often apparently concentric, of hydrated peroxide of iron, crossing the mass at 
various angles, or curved and contorted. Sometimes these appear as small nodules which 
desquamate on exposure, or when struck with the hammer. In such cases the outer portions 
only are composed of the hydrated peroxide, while the inner part is still a carbonate of iron, 
the change having probably been effected by the percolation of water. At Cuyahoga falls, I 
saw some beautiful exhibitions of these iron seams, and this character continues in every locality, 
in greater or less degree, as far as examined westward; the ore frequently forming nodules 
or accretions.* From what I was able to learn from other observers, in Michigan, there is a 
considerable quantity of similar ore in the same situation in that State. 
In the vicinity of Cuyahoga falls, the conglomerate may be seen passing beneath the coal 
which is worked in several places in that neighborhood ; the principal mines which I saw, are 
those on the farm of Henry Newberry, Esq. Below the falls the Chemung group is distinct¬ 
ly characterized, containing, however, few fossils compared with the same further east. I 
obtained enough to convince me of its identity, and I have since received from Mr. Newberry 
several others, which at that time I did not see. The most abundant fossil is a species of 
Strophomena. Beside this, there is an Atrypa, a Cypricardia, an Orbicula, a Lingula, a 
small Crinoid, and one or two undescribed forms. 
At Akron, the rocks of the Chemung group appear beneath the conglomerate, which is 
there in its lower part a coarse grey sandstone. The same fossils as before noticed, occur on 
a small stream by the side of the canal, below this village. 
Passing south from Akron to Greentown, I came to beds of coal, succeeded by a dark- 
colored shaly limestone, which abounds in fossils. Among these were two or three species 
See the description of this rock, chapter vii, pages 287 and 288, of this Report 
