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National Geologic Map Database

Geologic Unit: Karnak

Usage:

Karnak Limestone Member of Ste. Genevieve Formation (KY)
Karnak Member of Ste. Genevieve Limestone (IL,IN*)


Subunits:

Bryantsville Breccia Bed (IN)


Geologic age:

Middle Mississippian (Visean; early Chesterian)*


Type section, locality, area and/or origin of name:

Type section: exposures 4 mi northwest of Karnak, in SW/4 SW/4 SW/4 sec. 32, T. 13 S., R. 2 E., and NW/4 NW/4 NW/4 sec. 5, T. 14 S., R. 2 E., Dongola quadrangle, Johnson Co., IL (Swann, 1963).


AAPG geologic province:

Illinois basin*


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).