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.
The name was introduced into Arkansas in 1927, replacing part of the, now abandoned, Izard Limestone.
This article about a specific stratigraphic formation in the United States is a stub.