File:Cuyahoga Formation (Lower Mississippian; South Fork of the Licking River, Heath, Ohio, USA) (44443930484).jpg

Sandstones over gray shales in the Mississippian of Ohio, USA. (photo by James Cheshire)

The Cuyahoga Formation is a marine, mixed-siliciclastics succession in the Lower Mississippian of eastern Ohio. Many members and submembers have been named, based on whether the dominant lithology is shale or sandstone. In the lower and middle portions of the river cut shown here, gray shale dominates. This is the Raccoon Shale Member, named after Raccoon Creek, which runs from Alexandria to Granville to Newark, Ohio. The lighter-colored beds at the top of the cut are sandstones, traditionally identified as the Black Hand Sandstone Member of the Cuyahoga Formation. These sandstones are genetically and temporally unrelated to the true Black Hand Sandstone (see: <a href="https://www.flickr.com/photos/jsjgeology/albums/72157669040737430">www.flickr.com/photos/jsjgeology/albums/72157669040737430</a>). The sandstones seen here are part of an unnamed member here nicknamed the "Dugway Member", in reference to their presence at the Dugway Outcrop at the Route 16-Granville Road confluence in the western part of Newark, Ohio.

Stratigraphy: Raccoon Shale Member, Cuyahoga Formation, Kinderhookian Stage, lower Lower Mississippian