| Plattin Limestone | |
|---|---|
| Stratigraphic range: Ordovician | |
| Type | Formation |
| Unit of | Black River Group |
| Underlies | Kimmswick Limestone, Kope Formation, Lexington Limestone, and Trenton Limestone |
| Overlies | Joachim Dolomite and Pecatonica Formation |
| Thickness | up to 250 feet in Arkansas[1] |
| Lithology | |
| Primary | Limestone |
| Location | |
| Region | Arkansas, Illinois, Missouri |
| Country | United States |
| Type section | |
| Named for | Plattin Creek, Jefferson County, Missouri |
| Named by | Edward Oscar Ulrich[2] |
The Plattin Limestone is a Middle Ordovician geologic formation in Arkansas, Illinois, and Missouri.[1] The name was first introduced in 1904 by Edward Oscar Ulrich in his study of the geology of Missouri.[2] A type locality was designated at the mouth of the Plattin Creek in Jefferson County, Missouri, however a stratotype was not assigned. As of 2017, a reference section has not been designated. The name was introduced into Arkansas in 1927, replacing part of the, now abandoned, Izard Limestone.[3]