Usage:
Girardeau Limestone (IL*,MO*)
Girardeau Limestone of Maquoketa Group (IL*,MO*)
Geologic age:
Ordovician, Late*
Cincinnatian*
Type section, locality, area and/or origin of name:
Named from exposures 1.5 to 2 mi above Cape Girardeau, Cape Girardeau Co., eastern MO (Swallow, 1855).
AAPG geologic province:
Ozark uplift*
Illinois basin*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"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 conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).