Logan Formation


The Logan Formation is the name given to a Lower Carboniferous siltstone, sandstone and conglomeratic unit exposed in east-central Ohio and parts of western West Virginia, USA.

Stratigraphy and paleoenvironment

The Logan Formation was named by Andrews and originally described as a "buff-colored, fine-grained sandstone" above the Waverly Formation and below the Maxville Limestone. Bork and Malcuit concluded that the Logan Formation was deposited on a shallow marine shelf in a generally transgressing sea. The age of the Logan Formation has been established as early Osagean by the occurrences of brachiopods, ammonoids, conodonts and miospores.