58 Saliferous Rock Formation in the Valley of the Ohio. 



No. Description of strata. Thickness— feet. inch. 



often contains mica between the layers or beds. 

 Near the top of this .formation the beds are thin, 

 varying from two to twelve inches, and increasing to 

 many feet in thickness near its bottom ; the lower 

 strata often contain fossil vegetable remains. Beds 

 of coal are also found at various depths, but gener- 

 ally thin, the thickest being near the base of the hills. 80 



3. A grey colored, fine, argillaceous stone, generally free 



from mica; very compact and heavy, containing 

 geodes of argillaceous iron. This rock is sometimes 

 of a laminated structure, containing many fossil vege- 

 table remains of fern, palm leaves, &c. - - 20 



4. Bituminous coal* — This deposit, with the superin- 



cumbent slate, varies in thickness from three to nine 

 or more feet. Vegetable impressions are common 

 in the slate stone above the coal. The coal is easily- 

 fractured in the course of its horizontal direction, 

 every lamina being divided by a thin layer of pure 

 charcoal, exhibiting the grain and fibre of a woody- 

 structure. Tts vertical fracture is glistening. Large 

 quantities of iron pyrites are found amongst the slate 

 and sometimes in the coal itself. It contains much 

 bitumen, and burns with great freedom, - - 9 



5. Sparry lime rock; eight or ten feet in thickness, with 



•a bed of fine white clay over it, between the coal 

 and limestone ; color light grey, and often containing 

 iron pyrites, in rhombic and many sided crystals, 

 but generally free of fossil shells, from this place to 

 the mouth of the Muskingum. Higher up, in the 

 vicinity of Zanesville the lime rock abounds in 

 fossils. - - - - - 10 



6. Argillaceous sandstone. — Color bluish. The rock in 



which the boring for salt water commences, when 

 exposed to rain and atmospheric influence, it is read- 

 ily decomposed, into a light pulverulent earth. - 53 



* In some places two or three beds of coal are found, between the bottom and the 

 top of the sandstone hills, but generally thin, or only one or two feet thick. 



