Shales in the Devonian of Ohio, USA.

This outcrop in central Ohio consists of dark-colored, chippy-weathering, marine mudshales of the Late Devonian-aged Ohio Shale. The formation has been subdivided into three parts (in ascending order): Huron Shale Member, Chagrin Shale Member, and Cleveland Shale Member. The outcrop appearances of the three different members are best developed in northeastern Ohio, in the Cleveland area. The Huron and Cleveland are black shales and the Chagrin is gray shale. In central Ohio, the Chagrin Shale lithofacies occurs in a relatively thin, poorly developed interval - it is referred to as the Three Lick Bed. The Three Lick consists of interbedded gray and black shales.

These black shales were deposited in a moderately deep, anoxic seafloor environment. This was a widespread lithofacies during the Late Devonian. The Ohio Shale is equivalent to the Chattanooga Shale, the Antrim Shale, and the New Albany Shale in surrounding states.

Stratigraphy: Ohio Shale, Famennian Stage, upper Upper Devonian