USGS Visual Identifier
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Geologic Unit: Madrid

Madrid Formation (ME*,NH*)

Silurian, Late(?)*
Geologic Province:
New England province*

Areal Extent:

Type Locality:
Not designated. Named from exposures in the Anson 15-min quadrangle, west-central ME (Cariani, 1959).

Unit Name History:
Named (Cariani, 1959, unpub. dissert.).
Revised (Moench and Pankiwskyj, 1988).
Revised; Areal limits (Moench, 1990).
Overview; Revised; Age modified; Extended into NH; Areal limits (Moench and others, 1995).
NH State Geol. Map usage (Lyons and others, 1997).

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