Usage:
Blue River Group (IN*)
Blue River Group of /Mammoth Cave megagroup [informal] (IN)
["Megagroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). Considered informal and should not be capitalized.]
Subunits:
(alphabetical) --all in IN*: Paoli Limestone, St. Louis Limestone, Ste. Genevieve Limestone.
Geologic age:
Middle Mississippian (Visean; early Chesterian)*
Type section, locality, area and/or origin of name:
Notable exposures along banks of Blue River which drains parts of Washington, Harrison, and Crawford Cos., south-central IN (Gray and others, 1960).
AAPG geologic province:
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 ([ ]).