In northeastern Ohio the Ohio black shale of early reports was divided by Dr. Newberry into the Huron, Erie, and Cleveland shales,2 of which the Erie was later renamed the Chagrin by Professor Prosser,3 the entire succession up to the Berea thus becoming :
in which the type Huron may be largely contemporaneous with the Chagrin4 and only partly identical with the “Huron” beneath the Chagrin, in the well logs. More recently these strata of northeastern Ohio have been most carefully described by Prosser,5 whose work furnishes the foundation for the present writing.
Cleveland black shale
Huron black shale
In northwestern Pennsylvania Dr. I. C. White described the following succession in Erie and Crawford counties, adjacent to Ohio and western New York :6
Oil Lake group
The relations . . .