Shales in the Devonian of Kentucky, USA. (geology hammer for scale)

This is a weathered shale outcrop in southern Kentucky. The Chattanooga Shale of Kentucky and Tennessee consists of dark-colored, chippy-weathering, marine mudshales of Late Devonian age. These black shales were deposited in a moderately deep, anoxic seafloor environment. This was a widespread lithofacies during the Late Devonian's Global Anoxia Event. The Chattanooga Shale is equivalent to the Ohio Shale, the Antrim Shale, and the New Albany Shale in surrounding states.

Stratigraphy: Chattanooga Shale, Upper Devonian