Alpena Limestone

{{Short description|Geologic formation in Michigan}}

{{Infobox rockunit

| name = Alpena Formation

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| type = Formation

| age = Middle Devonian

| period = Middle Devonian

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| region = Michigan

| country = United States

| coordinates =

| unitof = Traverse Group

| subunits = Four Mile Dam Member and Newton Creek Member

| underlies = Thunder Bay Limestone

| overlies = Long Lake Limestone

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

{{Portal|Earth sciences|Michigan|Paleontology}}