Ammonoosuc Volcanics (CT*,ME*,MA*,NH*,VT*)
latest Middle to earliest Late Ordovician*
Type locality: in district bounded on north by Slate Ledge School and Partridge Lake, and on south by Youngs Pond (Ogontz Lake) and Tinkerville, Grafton Co., northern NH. Named from Ammonoosuc River (Billings, 1935).
New England province*
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 ([ ]).