SHELBY COUNTY. . 4G5 



ity of Piqua, are here abundantly seen — Halysites catenulata, Stroma- 

 topora, Asyringipora, and some species of Favosiies. These were exposed 

 on the surface. No fossil shells were to be seen. Fragments of crinoid 

 stems seemed to compose a considerable portion of the rock, and several 

 species of Fenestella abounded. This formation has never been quarried 

 here, apparently, for any economical purpose. It is in the neighborhood 

 of an excellent limestone belonging higher up, and which furnishes 

 lime of the first quality. The Clinton formation furnishes no good 

 building stone in this part of the State, and, while it makes the strongest 

 kind of lime, it is hard to burn, and heats greatly in slacking, and sets 

 rapidly when mixed. It is highly esteemed in paper-mills, where a 

 strong lime is desired, as it more readily softens the material used in the 

 manufacture of paper. 



The next formation ascending, is that known as the Niagara. It is 

 not seen here in actual contact with the preceding, as the exposure is 

 not continuous ; but within about a mile of the river, an out-crop of 

 stone is observed on and near the banks of the river. A casual exam- 

 ination shows that a great change has taken place in the character of 

 the stone. We have not only passed to a new formation, but into the 

 upper strata of it. The stone is neither well stratified nor compact, and 

 not suitable 'for building purposes. It is porous, comparatively soft, and 

 very fossiliferous, and of a light blue color. It is burned here into an 

 excellent lime, known locally as the Pontiac lime. The strata of the Niag- 

 ara, so much prized for building purposes, found at Piqua, and also those 

 found at Covington, Miami county, belong below this horizon. The su- 

 perposition of this quality of stone upon that of the Covington quarries, is 

 ocularly demonstrated on the Stillwater. This river rises gradually up 

 to the level of and above the stone of the Covington quarries above Cov- 

 ington. At the village of Clayton, on the Stillwater, about two miles 

 north of Covington, the banks of the river are formed of the same strata 

 as those from which the Pontiac lime is made, within about a mile of 

 the last exposure of the Clinton, on the Great Miami. The last exposure 

 of the Clinton on the Stillwater, is several miles south of Covington; 

 and a familiar example of the Clinton stone maybe given in the falls of 

 the Panther Creek. It will be seen that all that thickness of building 

 stone about the town of Covington, and exhibited so well at the falls of 

 Greenville Creek, as well as that of the Piqua quarries, belongs above 

 the Clinton and below the strata which first appear above it on the 

 Miami, near where the " Pontiac " lime-kilns are situated. The infer- 

 ence follows, that if there is any good building stone within Shelby 



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