Black shale with burrow from the Mississippian of Ohio, USA. (~7.3 centimeters across at its widest)

The Sunbury Shale is a black mudshale succession in Ohio - it is the oldest fully Mississippian-aged unit in the state. It occurs above the Berea Sandstone and below the Cuyahoga Formation. The Sunbury essentially identical to the older Ohio Shale. Compared with the Ohio Shale, the Sunbury is considerably thinner. Sunbury outcrops are uncommon.

The gray-colored band in this shale sample is a fossil burrow. Such structures are called trace fossils, which are any indirect evidence of ancient life. They refer to features in rocks that do not represent parts of the body of a once-living organism. Traces include footprints, tracks, trails, burrows, borings, and bitemarks. Body fossils provide information about the morphology of ancient organisms, while trace fossils provide information about the behavior of ancient life forms. Interpreting trace fossils and determination of the identity of a trace maker can be straightforward (for example, a dinosaur footprint represents walking behavior) or not. Sediments that have trace fossils are said to be bioturbated. Burrowed textures in sedimentary rocks are referred to as bioturbation. Trace fossils have scientific names assigned to them, in the same style & manner as living organisms or body fossils.

The burrow seen here has a gray mud infilling derived from basal shales of the overlying Cuyahoga Formation.

The tiny whitish specks in the black shale appear to be reflective phyllosilicate grains (mica), plus some pyrite (?).

Stratigraphy: Sunbury Shale, Kinderhookian Stage, lower Lower Mississippian