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Ionia Formation
Stratigraphic range: Jurassic
Type	Formation
Underlies	Glacial drift
Overlies	Grand River Formation
Location
Region	Michigan
Country	United States

The Ionia Formation is a geologic formation in Michigan. It preserves fossils dating back to the Jurassic period.

References

• Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 25 March 2022. Retrieved 17 December 2021.^{[ shallow reference ]}

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