Akah Substage of Four Corners Stage (AZ,CO,NM,UT)
Akah production interval (informal) of Paradox Member of Hermosa Formation (CO,UT)
Akah zone (informal)
For informal usage, the rank or lithologic term should not be capitalized.
Middle Pennsylvanian (Desmoinesian)
["Type section"] (subsurface): depth-interval approx. 5,700 to 6,950 ft, Shell No. 1 Hovenweep well, in sec. 5, T. 40 S., R. 26 E., San Juan Co., UT (Baars and others, 1967).
Paradox basin
Black Mesa basin
San Juan 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 ([ ]).