Milwaukee Formation

Milwaukee Formation
Stratigraphic range:
Givetian
One meter vertical section of Milwaukee Formation at its type locality in Estabrook Park, Milwaukee County, Wisconsin. Vegetation is seen at disconformity between the Lindwurm and Berthelet Members.
TypeGeological formation
Sub-unitsAscending: Berthelet Member, Lindwurm Member, North Point Member
Thickness17-21 meters
Lithology
PrimaryArgillaceous dolomite and shale
Location
CoordinatesType locality: 43.0985° N, 87.9057° W
RegionNorthern Milwaukee County, Wisconsin
CountryUnited States
Type section
Named forMilwaukee, Wisconsin
Named byW. C. Alden, 1906

The Milwaukee Formation is a fossil-bearing geological formation of Middle Devonian age in Milwaukee County, Wisconsin. It stands out for the exceptional diversity of its fossil biota. Included are many kinds of marine protists, invertebrates, and fishes, as well as early trees and giant fungi.[1]

Once a prolific source of fossils, the Milwaukee Formation exposures are now mostly buried, inaccessible, on private property, or located in areas where collecting is prohibited. Most of these exposures are or were located along the Milwaukee River and Lake Michigan shore.[1]

  1. ^ a b Gass, Kenneth C.; Kluessendorf, Joanne; Mikulic, Donald G.; Brett, Carlton E. (2019). Fossils of the Milwaukee Formation: A Diverse Middle Devonian Biota from Wisconsin, USA. Manchester, UK: Siri Scientific Press. ISBN 978-0-9957496-7-2.