Usage:
DeGraff Coal Member of Modesto Formation (IL)
Possibly spelled De Graff?
Geologic age:
Middle Pennsylvanian
Type section, locality, area and/or origin of name:
In southeast corner of NE/4 SW/4 sec. 21, T. 5 S., R. 4 E., Perry Co., southeastern IL. Named from DeGraff School about 1 mi northeast of exposure (Kosanke and others, 1960).
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 ([ ]).