Allegheny Formation (MD*,OH*,PA*,VA*,WV*)
Allegheny Group (OH,PA*)
Glen Richey (PA), Laurel Run (PA), Mineral Springs (PA), Millstone Run (PA), Clearfield Creek (PA); Clarion (OH,MD*,PA,WV), Kittanning (PA*), Freeport (PA*,MD, OH*,WV*); Putnam Hill (OH*,PA*); Vanport (PA*,MD*,OH*,WV*); Butler (MD*,PA*), Worthington (MD*,PA*); Washingtonville (OH,PA,WV), Columbiana (OH).
Named from exposures in valley of Allegheny River, western PA (Rogers, 1840).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.
"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 ([ ]).