USGS Visual Identifier
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Geologic Unit: Cobble Mountain

Cobble Mountain Formation (MA*,CT*)

Ordovician, Middle*

Geologic Province:
New England province*

Areal Extent:

Type Locality:
Type area: along and near southeast shores of Cobble Mountain Reservoir, including outcrops along Cobble Mountain Road and point of land that extends northward into Reservoir 2.3 km west of southeast corner of Blandford quadrangle, Hampden Co., southwestern MA (Hatch and Stanley, 1973).

Unit Name History:
Named (Hatch and Stanley, 1973).
Revised, Extended into CT (Stanley and others, 1980).
MA State Geol. Map usage (Zen and others, 1983).
Revised, age discussed (Stanley and Hatch, 1988).

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