USGS Visual Identifier
National Geologic Map Database logo GEOLEX database

Geologic Unit: Granby

Granby Basaltic Tuff of Newark Supergroup (MA*)

Jurassic, Early*

Geologic Province:
New England province*
Hartford basin*
Areal Extent:

Type Locality:
Exposed 1.25 mi north of cemetery in Granby and 1 mi east of The Notch, Holyoke quadrangle, Hampshire Co., MA (Emerson, 1898).

Unit Name History:
Named Granby tufa (Emerson, 1891).
Redescribed as Granby tuff (Emerson, 1898).
Revised (Balk, 1957).
MA State Geol. Map usage (Zen and others, 1983).
Redescribed as Granby Basaltic Tuff, assigned to Newark Supergroup (Robinson and Luttrell, 1985).

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