Usage:
Marshall Formation (MI*)
Marshall Sandstone (MI*)
Subunits:
Napoleon Member (MI*)
Geologic age:
Mississippian, Early*
Type section, locality, area and/or origin of name:
Named from exposures in vicinity of Marshall, Calhoun Co., southern MI (US geologic names lexicon, USGS Bull. 1200).
AAPG geologic province:
Michigan 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 ([ ]).