248 
[Assembly 
vial land on its north, east and west border. The solidity of the ore 
appears to be the cause of its not having been swept away with its 
original associates and its superincumbent masses. 
From all observations made, it is certain, that there are two distinct 
beds of red oxide of iron in the protean group, arranged in lines parallel 
to each other, extending from Herkimer to the Genesee river. These 
beds are about 25 feet from each other, and from 1 to 21 feet in thick- 
ness. They are not always present in every locality, for sometimes the 
one and sometimes the other, and even both, are wanting. A circum- 
stance readily conceivable over so great an extent, with masses compa- 
ratively thin, where opposing currents both general and partial may 
have existed, and w^here the surface over which the iron was floated may 
not have been level. 
It has happened, no doubt, frequently, that the surface over which 
the iron was floated admitted of its fine particles to escape, that is, to 
be absorbed by the floor upon which it was deposited. In this way we 
can explain the stains of iron upon the shales of Little Sodus bay, and 
of the mill at Martville, &c. &c. A whole bed could not disappear un- 
less passing over coarse sand, for the grains of which the greater part of 
the ore consists, must have been formed at the point of Thermal action. 
The concretionary limestone and its blue shale, as was made known 
in the second report, terminate this group. The limestone is first met 
with on the farms of Mr. Hood and Capt. Adams, south of Donnelly's 
ore bed. The shale and a more compact kind of limestone, were thrown 
out in digging a well between Donnelly's and the concretionary rock. 
Near to Joscelin's corners, on the farm of Enos Hubbard, it is burned 
for lime; so also in most of the towns of the Third District through 
which it passes. This limestone is readily known by its well defined 
characters, and is readily traced by its numerous quarries opened in the 
towns of Cicero, Lysander, Ira and Victory, all which are arranged in 
nearly an east and west line. 
In some of the quarries of the limestone there are small geodes whose 
sides are lined with crystals of carbonate of lime as at Lockport; in 
others, but more rarely, the limestone encloses globuliforra masses of 
pure white gypsum, and in others we find^ that singular concretionary 
rock which forms the upper part of the Lockport and Niagara limestone, 
being the terminal mass in the Third District, and from which its name 
was in part derived. In the upper part of the concretionary limestone, 
oolite is often found, showing that some of its particles w^ere subjected 
