USGS Visual Identifier
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Geologic Unit: Plainfield

Plainfield Formation (CT*,MA*,RI*)

Proterozoic, Late*

Geologic Province:
New England province*

Areal Extent:

Type Locality:
Type area: Plainfield Twp., eastern CT. Named from town of Plainfield, Windham Co., CT (Gregory, 1906).

Unit Name History:
Named Plainfield quartz schist (Gregory, 1906).
Revised to Plainfield quartz schist member of Putnam series (Foye, 1949).
Revised to Plainfield Formation (Lundgren, 1962).
Extended into RI (Feininger, 1965).
Extended into MA; Age modified (Barosh, 1976).
Age modified (Goldsmith, 1980).
Age modified; Areal limits (Goldsmith and others, 1982).
MA State Geol. Map usage (Zen and others, 1983).
Correlation discussed (Rankin, 1983).
Overview (Skehan and Rast, 1990).
Overview; Areal limits (Goldsmith, 1991).

Note: If you need more information, please contact Nancy Stamm (
Asterisks (*) indicate usage by the U.S. Geological Survey. Other usages by state geological surveys.

"No current usage" implies that a name has been abandoned or that it has fallen into disuse. Former usage and, if known, replacement name given in parentheses ().

Slashes (/) indicate unit name usage violates the 1983 North American Stratigraphic Code. This violation may be explained within brackets ([ ]).

U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA
Database project personnel
Last modified: 15-Jan-2013