139 



cliice mineral water. Fourth, in the western edge of the area, where the 

 limestone is under cover of the Chester formation, except in the deeper 

 valleys, the rock-water is artesian, and more or less highly impregnated 

 with mineral salts, as in the case of the water of the French Lick Val- 

 ley. In this part of the area mineral water is constantly making its way 

 from considerable depths to the surface, along the joints of the soluble 

 limestone, and consequently mineral springs abound, and even shallow 

 wells produce mineral water. 



Except in the valleys of White, Blue and Ohio rivers, the limestone 

 area contains, so far as known, no coarse deposits of alluvium, from whicli 

 water can be obtained, as in the Knobstone region. The larger valleys of 

 the area, with the exceptions already mentioned, are of two types. One 

 of these is represented by the headwaters of Indian Creek in Monroe 

 County, and by Lost River in Orange County, and Indian Creek in Har- 

 rison County. These creeks flow in broad shallow valleys on the lime- 

 stone upland, and have lost many of their tributaries and much of their 

 v.-ater by underground piracy to the deeper valleys on the east and west 

 Their floors are leaky, and their deposits of alluvium are thin and very 

 fine grained. The other type of valley is exemplified by Richland Creek 

 in Monroe and Greene Counties an.d by the lower course of Indian Creek 

 in Lawrence County, and by French Lick Creek. These valleys are deeply 

 intrenched, having cut through the Mansfield and Chester formations into 

 the top of the Mitchell limestone. They are broad, conspicuously terraced, 

 and have well-developed alluvial deposits; but the character and water- 

 bearing qualities of these deposits have not been carefully investigated. 



IV. 



Similar to the Knobstone region in topography, but differing consider- 

 jably in type of geological formation, is the area occupied by the Chester 

 find Mansfield formations. The Chester (Huron) formation consists of a 

 •series of limestones, shales and sandstones, varying from place to place in 

 ;the thickness of its members, and in the details of its lithology, but pre- 

 senting everywhere the following general sequence, in the ascending order : 

 (a) Lower sandstone, l to 12 feet thick; (b) Lower limestone, thin-bedded, 

 oolitic or lithographic, 2 to 5 feet; (c) Middle sandstone and shale, argil- 

 laceous or arenaceous shale and cross-bedded, soft sandstone, 45 to 62 feet 

 thick; (d) Middle limestone, crystalline, generally light colored, occasipti- 



