The Galena Group or Galena Limestone refers to a sedimentary sequence of
Ordovician limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...
that was deposited atop the
Decorah Shale. It is part of the Ordovician stratigraphy of the Upper Midwestern United States. It was deposited in a calm marine environment, and is fossiliferous.
[Mossler, J. and Benson, S., 1995, 1999, 2006]
Fossil Collecting in the Twin Cities Area
Minnesota at a Glance: Minnesota Geological Survey: University of Minnesota.
References
Geologic groups of Minnesota
Ordovician Minnesota
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