Usage:
Calvert Formation of Chesapeake Group (DE*,MD*,VA*)
Subunits:
(alphabetical): Alloway Clay Member (DE*,MD*), Calvert Beach Member (MD*,VA*), Fairhaven Member (MD*,VA*), Plum Point Marl Member (MD*), Popes Creek Sand Member (DE*,MD*,VA*).
Geologic age:
late Tertiary (early to middle Miocene)*
Type section, locality, area and/or origin of name:
Calvert Co., especially Calvert Cliffs, southern MD (Shattuck, 1902).
AAPG geologic province:
Atlantic Coast 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 ([ ]).