Dubuque Formation

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Dubuque Formation
Stratigraphic range: Ordovician
Type Formation
Underlies Maquoketa Formation
Overlies Galena Group
Location
Region Illinois, Minnesota
Country United States

The Dubuque Formation is a geologic formation in Illinois, Iowa, Wisconsin and Minnesota. It preserves fossils dating back to the Ordovician period. [1] It comprises carbonate and argillaceous rocks that are between 35 and 45 feet deep. [2]

See also

References

  1. Burr, J. H., Jr.; Swain, F. M. (1965). Ostracoda of the Dubuque and Maquoketa Formations of Minnesota and Northern Iowa. Minneapolis: University Of Minnesota. p. 1-3.{{cite book}}: CS1 maint: multiple names: authors list (link)
  2. Levorson, C.; Gerk, A.; Broadhead, Thomas (1 January 1979). "Stratigraphy of the Dubuque Formation (Upper Ordovician) in Iowa". Proceedings of the Iowa Academy of Science. 86 (2): 57–65. ISSN   0085-2236 . Retrieved 11 June 2025.