Usage:
Glenarm Group (DE*,DC*,MD*,NJ*,PA*,VA*)
Glenarm Supergroup (MD,PA)
Subunits:
GROUP STATUS (alphabetical): Cardiff Metaconglomerate (MD*,PA*), Chopawamsic Formation (VA*), Cockeysville Marble (DE*,MD*,PA*), James Run Formation (DE*,MD*), Peach Bottom Slate (MD*,PA*), Setters Formation (DE*,MD*,PA*), Wissahickon Formation (DE*,DC*,MD*,NJ*, PA*,VA*).
SUPERGROUP STATUS (alphabetical): Cockeysville Marble (MD,PA), Peach Bottom Slate (PA), Setters Formation (MD,PA), Wissahickon Group (MD,PA).
Geologic age:
Neoproterozoic to Ordovician
Type section, locality, area and/or origin of name:
Not designated. Named from typical development near Glenarm, 13 mi northeast of Baltimore, MD (Knopf and Jonas, 1922).
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 ([ ]).