Usage:
Wissahickon Formation of Glenarm Group (DE*,DC*,MD*,NJ*,PA*,VA*)
Wissahickon Formation (DE)
Wissahickon Schist of Glenarm Group (MD)
Wissahickon Group (VA)
Subunits:
Marburg Schist Member of Wissahickon Formation (PA).
Geologic age:
Neoproterozoic to Ordovician*
Type section, locality, area and/or origin of name:
Not designated. Named from Wissahickon Creek, in Philadelphia, PA.
AAPG geologic province:
Piedmont-Blue Ridge province*
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 ([ ]).