THE CARBONIFEROUS SYSTEM. 89 



division is not so distinctly marked, and the whole mass is generally 

 more homogeneous ; consisting of beds from one to five feet in thickness. 

 At Independence the flagging stone has been mostly removed by glacial 

 erosion, and the section opened in the quarries consists of from 25 to 30 

 feet of massive sandstone. At Chagrin Falls the quarries of Mr. Hamil- 

 ton Goodale are opened in the upper member, while the lower forms 

 the ledge over which the water pours. 



In tracing the Berea grit eastward, it is seen to become less massive, 

 and in the eastern counties the layers of sandstone are intercalated with 

 beds of shale. On Oil Creek, and in other localities of western Pennsyl- 

 vania, the Lower Carboniferous series is more uniform in lithological char- 

 acter, and the Berea grit is hardly distinguishable ; the whole mass there 

 consisting of alternations of sandstone and shale, the upper portion being 

 more arenaceous and the lower more argillaceous than in Ohio. 



In tracing the members of the Waverly group southward toward the 

 central and southern parts of the State, a similar change was remarked, 

 as will be seen by the sections of this formation at various localities 

 given below. Even as far south, however, as the Ohio, the horizon of 

 the Berea grit is marked by an unusual prevalence of sandy matter, 

 and the famous City Ledge, quarried at Waverly and at various other 

 localities in that section of the State, is probably its equivalent. Its 

 greatest development seems to be in the north-western portion of 

 the area which it underlies, as in Lorain county, at Elyria, Amherst, 

 etc. Here the sandstone group has a thickness of sixty feet, and is 

 more massive throughout than any where else within the limits of the 

 State. 



In Michigan this group is apparently represented by the Napoleon 

 sandstone of Winchell, which has a thickness of 107 feet, while the over- 

 lying Cuyahoga shales have, perhaps, as their equivalent, the Michigan 

 Salt group, 184 feet thick. 



From these facts it would seem that this arenaceous material was de- 

 rived from the north-west, and that in the Ohio localities, where the 

 Berea sandstone is exposed, the group is thickest and coarsest where it 

 approaches nearest to the Michigan outcrops. Going east and south 

 from Lorain county — the point of greatest development of this formation 

 within our State — its arenaceous material progressively diminishes, until 

 in Kentucky or Tennessee scarcely any sandstone, properly speaking, 

 is found in the series, and in eastern Ohio and western Pennsylvania 

 argillaceous material, derived from an eastern source, enters into the 

 composition of the beds. At Mansfield the Berea grit is seen to be con- 

 verted into highly colored red and yellow sandstone, much softer than 



