Usage:
Fern Glen Formation (IL*,MO*)
Fern Glen Limestone (IL*,KS*,MO*)
Fern Glen Formation of Mammoth Cave Group (IL-notably southwestern part)
Subunits:
(alphabetical): Meppen Limestone Member (MO), Reeds Spring Limestone Member (KS), St. Joe Limestone Member (KS).
Geologic age:
Mississippian, Early*
Osagean*
Type section, locality, area and/or origin of name:
Named from exposures near Fern Glen Station [Fern Glen], 20 mi west of St. Louis, [southwestern St. Louis Co.], central eastern MO (Weller, 1909).
Type section (composite): two railroad cuts on either side of Fern Glen on north bank of Meramec River, in center SE/4 sec. 14 and NW/4 SW/4 SW/4 sec. 13, T. 44 N., R. 4 E., Manchester 7.5-min quadrangle, St. Louis Co., central eastern MO (Thompson, 1975).
AAPG geologic province:
Ozark uplift*
Forest City basin*
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 ([ ]).