THE CARBONIFEROUS SYSTEM. 95 



greenish shales, containing Leiorkynchus mesacostalis, Spirifera disjuncta, 

 etc., Chemung fossils, characteristic of the upper layers of the Erie shale. 

 Here, then, we have the base of the Lower Carboniferous series. The first 

 of the Chemung fossils occur about sixty feet below the base of the Cleve- 

 land shale, and it is possible that the intervening mass may be an 

 element in the Lower Carboniferous series, up to the present time not 

 sufficiently well known to be identified and described. As has been 

 stated, near the Ohio an interval of 147 feet separates the Cleveland 

 shale from the Huron shale below, and the material filling this interval 

 has similar lithological characters to the upper portion of the Waverly, 

 but no fossils have been obtained from it, and it is therefore impossible 

 at present to say whether it contains any representative of the Erie 

 shale or not. 



The following is a minute section taken at this point by Mr. R. D. 

 Irving, one of the assistants on the Survey : 



SECTION OF THE STKATA BETWEEN THE CLEVELAND AND HTJKON SHALES, SCIOTO 



COUNTY, OHIO. 



Sandstone (City Ledge) 3' 5" 



Blue and drab shales 3' 9" 



Blue clay V 7" 



Black shale (Cleveland shale) 15' 6" 



Sandstone V 4" 



Shales and sandstone 1' 9" 



Sandstone 9" 



Shale, with three layers of sandstone 6' 6" 



Sandstone 1' 4" 



Shale, with three layers of sandstone 6' 9" 



Sandstone 2' 6" 



Shale, with three layers of sandstone 9 / ll" 



Sandstone 1' 2" 



Shale 5" 



Sandstone V 5" 



Shale 3' 9" 



Sandstone 10" 



Shale 3' 1" 



Sandstone 1' 2" 



Shale V 11" 



Sandstone 2' 10" 



Three layers of shale and sandstone 11' 9" 



Sandstone V 4" 



Shale 10" 



Sandstone V 10" 



Shale V 2" 



Sandstone 11" 



Shale Y 2" 



