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National Geologic Map Database

Geologic Unit: Baldwin

Usage:

Baldwin Formation (IL)


Geologic age:

Middle Mississippian (Visean; early Chesterian)


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

Named from town on east side of Kaskaskia River in Randolph Co., southwestern IL. Outcrops extend from near Baldwin to Fort George and thence along Missisippi bluff to mouth of Marys River (Weller, 1939).


AAPG geologic province:

Illinois basin


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 ([ ]).