Usage:
Obryan Member of Princess Formation of Breathitt Group (KY)
Obryan Member of Breathitt Formation (KY*)
Obryan Member of Allegheny Formation (OH*)
Obryan limestone (informal, unranked) in Allegheny Group (OH)
For informal, unranked usage, the lithologic term should not be capitalized.
Geologic age:
Middle Pennsylvanian (Moscovian; Westphalian D; Desmoinesian)*
Type section, locality, area and/or origin of name:
Type locality: power line paralleling U.S. Highway 23, 1.6 km east of Obryan Cemetery, just north of BM 544, Ironton 7.5-minute quadrangle, Greenup Co., northeastern KY (Rice and others, 1994).
Reference section: just above and about 6 m northeast of U.S. Highway 52 in OH just opposite Ashland, KY (Rice and others, 1994).
AAPG geologic province:
Appalachian 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 ([ ]).