Deer Valley Limestone Member of Greenbrier Formation (MD*)
Deer Valley Limestone Member of Mauch Chunk Formation (MD,PA)
Deer Valley Limestone Tongue of Greenbrier Limestone Member of Mauch Chunk Formation (PA)
Middle Mississippian (Visean; early Chesterian)*
At Keystone Lime Co., quarry, 1.5 mi southwest of Mount Davis, Somerset Co., PA. Extends into Garrett Co., MD (Flint, 1965).
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 ([ ]).