USGS Visual Identifier
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Geologic Unit: Mount Garfield

/Mount Garfield Porphyritic Quartz Syenite of White Mountain Plutonic-Volcanic Suite (NH*)

Triassic, Late(?)*
Jurassic, Early*
Geologic Province:
New England province*

Areal Extent:

Type Locality:
Type area: From just north of Mount Hale southwest to Hardwood Ridge, Franconia 15-min quadrangle, Grafton Co., northwestern NH. Named from Mount Garfield (Billings and Williams, 1935).

Unit Name History:
Named (Billings and Williams, 1935).
Age modified; Isotopic dating (Lyons, 1964).
Isotopic dating (Eby and others, 1992).
Age modified; Isotopic dating (Moench and others, 1995).
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