USGS Visual Identifier
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Geologic Unit: Quincy

Quincy Granite (MA*)
Quincy Granite of the Blue Hills Complex (MA)

Ordovician, Late*
Silurian, Early*
Geologic Province:
New England province*

Areal Extent:

Type Locality:
Type area: Quincy and Milton, Essex Co., northeastern MA (Emerson, 1917).

Unit Name History:
First used (Crosby, 1880).
Overview (Emerson, 1917).
Revised; Age modified (Toulmin, 1964).
Age modified; Isotopic dating (Zartman, 1977).
MA State Geol. Map usage (Zen and others, 1983).
Areal limits; Revised; Overview (Skehan and Rast, 1990).
Overview; Areal limits; Age modified (Wones and 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