The age of the formation is difficult to determine, because of a lack of diagnostic fossils.
Roughly, the formation dates from the Late Kinderhookian (354.8 to 350.8 million years ago) to the Middle Osagean (347.7 to 344.5 million years ago).
[1] Eight members are recognized, among them the Orangeville Shale, Sharpsville Sandstone, and Meadville Shale.
[2] It preserves fossils dating to the Mississippian subperiod of the Carboniferous period.
This article about a specific stratigraphic formation in Ohio is a stub.