BIG SPRING PRAIRIE. 9 
-quarries varies from a gentle dip of 5° to as high as 18°. 
The ridges are perforated with numerous sink-holes 
and subterranean water channels, from one of which 
the Carey Water Works obtains its supply for the town. 
The dip of the strata and the subterranean water 
‘supply have considerable bearing upon past and pres- 
ent conditions of prairie, as will be explained later. In 
the Ohio Geological report the following theory to ac- 
count for those ridges occurs: “It would seem as if 
the conditions of the ocean’s bed in which the Niagara 
was formed were not uniform. While regular strata 
were being deposited in a wide area, including portions 
-of Seneca and Hancock Counties, without disturbance 
or contortions, a concretionary and crystallizing force 
sprang up into operation in the northwest corner of 
Wyandot County which in working from below, caused 
the even beds of deposition to swell upward over the 
growing mass or masses. In some cases it aided in the 
preservation of fossil remains. In others it hastened 
their absorption into the mass of rock. ‘This is a pecu- 
liarity of the rock formation not confined to the Niagara, 
butis displayed conspicuously in the water-lime above, 
and it has been seen inthe corniferous. When the lapse 
of time brings such hardened masses into contact with 
the erosions of ice and water, they cause the prominent 
features of the landscape by the removal of the more 
destructible parts about them. Such may be the ex- 
planation of the remarkable ridges about Carey, the 
even friable beds seen in the quarries about their flanks 
having once been continuous over their summits, but 
unable to resist the forces of the glacial epoch were de- 
nuded down to the more enduring rock.”’ 
Thus the summits of the ridges, which are com- 
paratively narrow for the greater part of their extent 
consist of a very hard Niagara Limestone, while there 
is a gradual transition in hardness along the sides to 
the rather friable strata along or near the bases. 
