Usage:
Petersburg Formation of Carbondale Group (IN*)
Subunits:
(alphabetical) --all in IN*: Folsomville Member, Houchin Creek Coal Member, Springfield Coal Member, Stendal Limestone Member.
Geologic age:
Middle Pennsylvanian (Moscovian; Westphalian; Desmoinesian)*
Type section, locality, area and/or origin of name:
Petersburg, Pike Co., southwestern IN (Fuller and Ashley, 1902).
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 ([ ]).