Usage:
Delavan Member of Tiskilwa Formation of Wedron Group (IL)
Geologic age:
Quaternary (Pleistocene; Wisconsinan)
Type section, locality, area and/or origin of name:
Type section: roadcuts along Illinois Highway 121, 4 mi [6.4 km] east of Delavan, in SW/4 sec. 16, T. 22 N., R. 3 W., [Emden 7.5-min quadrangle], Tazewell Co., northeastern IL. Named from Delavan, Tazewell Co., northeastern IL (Willman and Frye, 1970).
AAPG geologic province:
Illinois 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 ([ ]).