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National Geologic Map Database

Geologic Unit: Egremont

Usage:

Egremont Phyllite (CT,MA*,NY)


Geologic age:

Ordovician, Late*
Ordovician, Middle*


Type section, locality, area and/or origin of name:

Named from its wide extent in Egremont Valley, Berkshire Co., southwestern MA (Hobbs, 1893).
Type locality: town of Egremont, Egremont 7.5-min quadrangle, MA (Zen, 1964, 1966).


AAPG geologic province:

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 ([ ]).