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National Geologic Map Database

Geologic Unit: Stephens Forest

Usage:

Stephens Forest Formation of Marmaton Group (IA)


Subunits:

(alphabetical): Higginsville Limestone Member, Houx Limestone Member, Little Osage Shale Member.


Geologic age:

Middle Pennsylvanian (Desmoinesian)


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

In NW/4 sec. 18, T. 72 N., R. 22 W., Lucas Co., IA (Ravn and others, 1984).


AAPG geologic province:

Iowa shelf


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 ([ ]).