Usage:
Rapid Member of Little Cedar Formation of Cedar Valley Group (IA)
Rapid Member of Cedar Valley Formation (IL)
Geologic age:
late Middle Devonian (Givetian)*
Type section, locality, area and/or origin of name:
Not synopsized to date.
AAPG geologic province:
Iowa shelf
Illinois basin
Wisconsin arch
Lincoln anticline
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 ([ ]).