Usage:
/Petersburg Silt (IL)
[Preoccupied. Name previously applied to Pennsylvanian Petersburg Formation by Fuller and Ashley (1902) in IN.]
Geologic age:
Quaternary
Pleistocene
Illinoian
Type section, locality, area and/or origin of name:
Type section: Roadcut south of Petersburg, in NW/4 NW/4 NE/4 sec. 23, T. 18 N., R. 7 W., Menard Co., central IL (Glass and Frye, 1963).
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 ([ ]).