Notice of Geological Surveys. 135 



Dislocations of a few inches are occasionally seen. The rocks 

 dip very gradually toward the west. " Large quantities of argilla- 

 ceous iron ore and carbonate of iron are associated with the slaty 

 clays of the formation at its eastern border, where are" excel- 

 lent fire clays, potter's clay, furnace hearth-stones, and slates, 

 from which copperas and alum can be manufactured on a large 

 scale. Sandstones for building, for grind and whetstones, are 

 very superior. 



Boring for salt water through the white sandstones at the mar- 

 gin of the coal formation is encouraged, as they are regarded by 

 Dr. Owen as the equivalent of the saliferous formation of the 

 Muskingum and Kenawha. " A brine affording a pound of salt 

 from a gallon of water was procured near the mouth of Coal 

 Creek, in Fountain county," from a boring that passed through 

 the coal beds themselves to the depth of seven hundred feet. 

 Between the " soft, fine-grained, greyish or brownish grey sand- 

 stone of the knobs in Floyd county, and the coal formation" is a 

 series of limestones, the "oolitic" or "encrinital," of Kentucky 

 and of Tennessee, described by Dr. Troost in the iron region of 

 Tennessee. " This limestone formation is the termination of the 

 true carboniferous and saliferous rocks, and is distinguished by 

 the two characteristic fossils, the Pentt'emite and Archimedes, 

 and by its oolitic structure. It constitutes the only remarkable 

 diiference of the rocks of Indiana from those of Ohio, the latter 

 having instead a conglomerate from forty to eighty feet thick 

 succeeding the Waverly sandstone rock, and the former a series 

 of limestone some two hundred or three hundred feet thick, with 

 a great variety of fossil remains." 



The view here presented of the rocks of Indiana and Ohio, in- 

 dicates, we think, 1. That they were once continuous and un- 

 broken, as the blue limestone now is, which is the base of the 

 whole. If this be so — 2. That they were deposited upon a base 

 originally higher at about the junction of the two states, or there 

 has been subsequently a local elevation at this point. 3. The in- 

 clination of the strata as given by Dr. Locke, in a colored map and 

 section of Adams county, would carry the top of the coal strata of 

 Scioto, (the next county east,) if continued to the west line of Ad- 

 ams county, to a height of eleven hundred and sixty feet above it, 

 and if they be continued to the longitude of Cincinnati, say fifty 

 one miles west, " at the rate of one hundred feet in three miles" 



