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National Geologic Map Database

Geologic Unit: Franconia

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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).