88 
GEOLOGY OF THE FOURTH DISTRICT. 
In the next town westward, there is a light grey crinoidal limestone, which, from examina¬ 
tions made elsewhere, is found to come in above the dark compact beds on the Genesee, and 
below the concretionary mass (No. 3). It is abundant in loose fragments on the surface, but 
cannot be seen in place except in one or two instances. It is wrought as a fire-stone, and, 
from its porous nature, serves the purpose very well. It becomes more developed farther 
west, forming the beautiful and durable crinoidal limestone of Lockport, and extending to the 
Niagara river. 
In the south part of the town of Sweden, the upper strata of the limestone contain an abun¬ 
dance of coralline fossils, which, from the weathering of the surface, stand out in bold relief, 
exhibiting their structure in a most perfect manner. The best specimens can be obtained 
from the loose fragments, which are strewed over the surface in great profusion. 
In its extension through Orleans county, this limestone forms two distinct terraces ; the 
more northerly one being produced by the lower part of the rock, and the southern one by the 
higher strata. Its northern limit is from the town of Sweden to Clarendon centre ; thence by 
the south side of Jefferson lake, it continues west turning a little southward, and passes two 
miles south of Albion and about the same distance south of Medina. The southern terrace, 
or outcropping of the higher strata, is about two miles farther south. 
In its lithological characters, this rock suffers little change throughout this county. Its 
lower portions retain the character of a siliceous limestone, which continues, though somewhat 
unequally developed, as far as the Niagara river. At Shelby falls, in the town of Barre, it is 
unusually thick, and well exposed. From the former place the stone has been burned, and 
proved a good hydraulic cement. The crinoidal portion of the mass, which is so extensively 
quarried at Lockport, does not appear so well developed in Orleans county, though it exists 
in all localities, having the same characters as in Monroe county. The quarries in this rock 
afford an abundance of good building stone, and lime, and it is easily accessible throughout 
the whole length of the county. In consequence, however, of this range passing from two to 
four miles south of the canal, and all the large villages being along the line of the latter, there 
has been little inducement to open extensive quarries, as stone is more readily supplied from 
other points. 
In Niagara county, this limestone passes through the towns of Royalton, Lockport, Cam¬ 
bria and Lewiston, and extends into the next southern range of towns. Its greatly increased 
thickness has rendered it an efficient protection to the shale beneath ; and this, instead of 
being worn down and spreading out over a broad surface, as in the eastern part of the district, 
forms only the northern slope of this great escarpment, often presenting a width of less than 
one quarter of a mile. This strongly marked feature of the country on the west of the Gene¬ 
see is entirely lost on the east, from the thinning of the limestone. Nearly the whole width 
of the formation in Niagara county is of the limestone ; while at the east, the shale covers the 
greater extent of surface occupied by the group. 
The two sections of Lockport and Niagara, the one an artificial and the other a natural one, 
exhibit not only the limestone, but the whole group to the greatest possible advantage. At 
Lockport the shale, as elsewhere, passes into beds of impure siliceous limestone ; and these, 
