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, 

 but is displayed conspicuously in the water-lime above, 

 and it has been seen in the 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. 



