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National Geologic Map Database

Geologic Unit: Obryan

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