Usage:
Franconia Sandstone (IL*,IN*,IA*,MI*,MN*,OH*,WI*)
Franconia Formation (IL*,IN*,MN*,MO*)
Franconia Formation of Knox Group (IL-notably in southern part)
Franconia Formation of Munising Group (IN,MI)
Franconia Sandstone Member of Munising Formation (MI)
Subunits:
(alphabetical): Birkmose Member (MO), Davis Member (IL), Derby-Doe Run Member (IL), Ironton Member (IL*,WI*,MI*), Mazomanie Member (WI*), Reno Member (MO,MN*,WI*), Tomah Member (MO).
Geologic age:
Late Cambrian*
Type section, locality, area and/or origin of name:
Type area: exposures in vicinity of Franconia, Chisago Co., MN (Berkey, 1897).
AAPG geologic province:
Sioux uplift*
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 ([ ]).