Usage:
Ionia Sandstone Member of Grand River Formation (MI)
Ionia Sandstone Member of Saginaw Formation (MI*)
Geologic age:
Pennsylvanian, Middle*
Type section, locality, area and/or origin of name:
Not stated. Probably named from exposures in abandoned quarries near Grand River between Lyons and Ionia, Ionia Co., southern MI (Kelly, 1936).
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 ([ ]).