Pecatonica Formation

Pecatonica Formation
Stratigraphic range: Ordovician
TypeFormation
Unit ofBlack River Group
UnderliesPlattin Formation
OverliesJoachim Dolomite
Lithology
PrimaryLimestone
Location
RegionIllinois, Indiana, Iowa and Wisconsin
CountryUnited States

The Pecatonica Formation is a geologic formation in Illinois. It preserves fossils dating back to the Ordovician period.