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National Geologic Map Database

Geologic Unit: Loyalhanna

Usage:

Loyalhanna Formation (PA)
Loyalhanna Limestone (MD*,PA*)
Loyalhanna Limestone Member of Greenbrier Formation (MD*)
Loyalhanna Limestone Member of Mauch Chunk Formation (PA)
Loyalhanna Member of Greenbrier Limestone (WV,MD)


Geologic age:

Middle Mississippian (Visean; early Chesterian)*


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

Named from exposures in gorge in which Loyalhanna Creek flows across Chestnut Ridge in Westmoreland Co., PA (Butts, 1904).


AAPG geologic province:

Appalachian basin*


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 ([ ]).