Pennington Formation

The Pennington Formation is a geologic formation named for Pennington Gap, Virginia. It is the uppermost of the Mississippian formations. According to general usage among geologists, the Pennington Formation is limited to the carbonate rocks and marine shales located above the highest massive limestone bed of the Newman Formation.

It preserves fossils dating back to the Carboniferous period, between 360 and 300 million years ago.