Berwick Formation of Merrimack Group (ME*,MA*,NH*)
Ordovician(?)*
Silurian(?)*
Named from development at Berwick, York Co., ME (Katz, 1917).
Reference section: in Salmon Falls River between Berwick, ME, and Somersworth, NH (Hussey, 1985).
New England 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 ([ ]).