GREENE COUNTY. 69] 
There are three prominent horizons of springs in 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 ef 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 te 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 peint 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, lisq., 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- 
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 
