Cummingsville Formation

Cummingsville Formation
Stratigraphic range: Ordovician
Cummingsville Formation in Decorah, Iowa. The Cummingsville is the brown upper unit; the Decorah Shale is below.
TypeFormation
OverliesDecorah Shale
Location
CountryUnited States
ExtentIowa and Minnesota

The Cummingsville Formation is a geologic formation in Iowa and Minnesota. It preserves fossils dating back to the Ordovician period.