Usage:
[?] /Ishpeming Basic Volcanics (MI)
[?] /Ishpeming formation (informal) (MI*)
According to US geologic names lexicon (USGS Bull. 896), Ishpeming abandoned; is considered an unnecessary name. Bijiki and Goodrich both recognized in the district. [Use of simple lithic terms is preferred and term "Formation" is applied to formal nomenclature (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021).]
Geologic age:
Paleoproterozoic
Type section, locality, area and/or origin of name:
Not designated. Named from typical exposures of the unit that surround and underlie the city of Ishpeming, MI (Lake Superior region) (Van Hise and Bayley, 1895).
AAPG geologic province:
Lake Superior region
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 ([ ]).