Plattin Limestone

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]

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]

See also

• Paleontology portal

• List of fossiliferous stratigraphic units in Arkansas
• Paleontology in Arkansas