Usage:
Irons Fork Mountain Formation of Jackfork Group (AR)
Geologic age:
Pennsylvanian, Early
Morrowan
Type section, locality, area and/or origin of name:
In secs. 21 through 24, 27, and 28, T. 1 S., R. 28 W., Polk Co., AR. Named from Irons Fork Mountain along U.S. Forest Service Road 216, (Morris, 1971).
Reference section: 50 mi east in Forked Mountain area, Little Cedar Creek anticline, from NW/4 sec. 4, T. 2 N., R. 19 W., to SW/4 sec. 33, T. 3 N., R. 19 W.; Saline Co. into adjoining Perry Co., AR (Morris, 1971).
AAPG geologic province:
Ouachita folded belt
Arkoma 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 ([ ]).