Usage:
Knobs Supergroup (KY)
Knobs Group (IL)
Subunits:
GROUP STATUS (alphabetical) --all in IL: Borden Siltstone, Chouteau Limestone, Meppen Limestone, New Albany Shale, Springville Shale; [interpreted from Kolata (2005) and Willman and others (1975, p. 127)].
Geologic age:
Devonian to
Mississippian
Type section, locality, area and/or origin of name:
Not designated. Named from "The Knobs," a narrow band of highly dissected terrain developed on Late Devonian and Early Mississippian shales that partially surrounds Bluegrass region and lies in front of Highland Rim, Muldraugh, or Knobstone Escarpment of KY (Swann and Willman, 1961).
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 ([ ]).