Usage:
Lacon Formation (IL)
Geologic age:
Quaternary
Pleistocene
Wisconsinan
Holocene
Type section, locality, area and/or origin of name:
Type section: landslip area along base of the bluffs of the Illinois Valley, 2 mi northwest of Lacon, in E/2 sec. 2, T. 12 N., R. 9 E., Marshall Co., north-central IL (Willman and Frye, 1970).
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 ([ ]).