USGS Visual Identifier
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Geologic Unit: Mascoma

Mascoma Granite of Oliverian Plutonic Suite (NH*)

Ordovician, Late*
Geologic Province:
New England province*

Areal Extent:

Type Locality:
Central part of Mascoma 15-min quadrangle, west-central NH (Chapman and others, 1938).

Unit Name History:
[Please note: only the Lyons and others (1997) reference includes a synopsis here. The remaining references have yet to be added from the GNC index card files. Until then, feel free to contact us if you would like complete bibliographic citations.]
Named Mascoma Group (Chapman and others, 1938).
Age modified (Bean, 1952; Lyons, 1964).
Revised to Mascoma Granite; Age modified (Lyons and Faul, 1968).
NH State Geol. Map usage; Age modified; Isotopic dating (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