Usage:
Charter Member of Mount Simon Formation (IL-subsurface)
Geologic age:
Late Cambrian
Type section, locality, area and/or origin of name:
Type section (subsurface): depth-interval 1,381 to 1,648 feet, McQueen No. 1 (well 6), in SW/4 NE/4 NE/4 sec. 27, T. 42 N., R. 3 E., DeKalb Co., northern IL. Named from Charter Oak School, 3.5 mi north of type well (Templeton, 1950).
AAPG geologic province:
Wisconsin arch
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 ([ ]).