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National Geologic Map Database

Geologic Unit: Prairie du Chien

Usage:

Prairie du Chien Group (IL*,IN*,IA*,MI*,MN*,OH*,WI*)
Prairie du Chien Group of Knox Supergroup (IN)


Subunits:

(alphabetical): Foster Formation (MI), Gunter Sandstone (IL), Oneota Dolomite/Formation (IN,IA*,IL*,MI*,MN*,WI*), Shakopee Dolomite/Formation (IN,IA*,IL*,MI*,MN*,WI).


Geologic age:

Ordovician, Early*
Ordovician, Middle


Type section, locality, area and/or origin of name:

Type area: exposures in vicinity of Prairie du Chien, WI (Bain, 1906).


AAPG geologic province:

Wisconsin arch*
Michigan basin*
Iowa shelf*
Cincinnati arch*


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).