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National Geologic Map Database

Geologic Unit: Penn Yan

Usage:

Penn Yan Shale Member of Genesee Formation (NY*,PA*)
Penn Yan Tongue of Genesee Formation (NY)
Penn Yan Shale of Genesee Group (NY)


Geologic age:

Devonian, Middle*
Devonian, Late*


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

Outcrops in streams along south side of Keuka Lake outlet near town of Penn Yan, Yates Co., NY. Well exposed in middle gully of three, draining north into outlet at Seneca Mills (Grossman, 1944).


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 ([ ]).