GREENE COUNTY. 691 



There are three prominent horizons of springs jn the strata of Greene 

 county. The lowermost of these marks the junction of the Lower and 

 Upper Silurian formations. All the conditions that favor the existence 

 of numerous and generous springs are found here. The Clinton limestone 

 furnishes a porous and fractured cap of considerable thickness, and the 

 terminal shales of the Cincinnati group supply the impervious stratum 

 which must turn the water outwards. It must also be remembered that 

 this horizon is shown only along the sides of valleys which in themselves 

 tempt the outflow of subterranean water. This whole geological bound- 

 ary is marked as a water-bearer. The fine spring at Goe's Station, which 

 has been used as a source of railroad supply, may be taken as a represent- 

 ative of the class. . The head spring of Ludlow Creek, on the line of the 

 Xenia and Fairfield pike, is another that belongs to this belt. They are 

 found by hundreds within the county. Occasionally springs issue from 

 some point in the Clinton formation where its base is not exposed. There 

 can be no doubt that in many such instances they have the same real 

 source as those already named. Several fine springs near Grinnell's Mill 

 belong to this category. 



At a point about seventy-five feet higher in the scale the second of 

 these water-bearing horizons is found. The summit of the Niagara 

 shales is here reached, and throughout their whole extent in southern 

 Ohio they make an important contribution to the natural water-supply. 

 The springs issuing from this source are confined to two townships in 

 Greene county, viz., Miami and Cedarville. Here, however, they are 

 both numerous and important. Characteristic examples of them can be 

 seen on the Water-cure grounds at Yellow Springs,-now the farm of A. V. 

 Sizer, Esq., along the gorge of the Little Miami from Grinnell's Mill to 

 Clifton, and in the valley of Massie's Creek for two miles below Cedar- 



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ville. 



The third and last of these water-bearing beds is found from twenty to 

 thirty feet above the one last named, in a shaly seam in the Springfield 

 division of the Niagara series. It is of much less importance than either 

 of the others in every way. The seam of shale is too thin to make an 

 effective stop to the descending water. Many fine springs, however, 

 especially in the vicinity of the village of Yellow Springs, must be re- 

 ferred to this horizon. The most remarkable of all, that from which the 

 village of Yellow Springs derives its name, appears to issue from this 

 level There is good reason, however, for believing that its source lies 

 deeper, and that its outlet is obstructed at its true horizon In other 

 words, it is probably derived from the greater belt of shales below Its 

 temperature varies but little with the change of seasons, and its volume 



