Usage:
Wilmette Bed of Sheboygan Member of Lake Michigan Formation (IL*,MI*,WI*)
Geologic age:
Quaternary*
Pleistocene*
Wisconsinan*
Type section, locality, area and/or origin of name:
Type section (subsurface): depth-interval 152 to 174 cm, water depth 119 m, Core 143, Lake Michigan, 51 km east of Waukegan, Lat. 42 deg. 21.8 min. N., Long. 87 deg. 10.8 min. W., Lake Co., IL. Named from Wilmette, Cook Co., IL (Lineback and others, 1970).
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 ([ ]).