USGS Visual Identifier
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Geologic Unit: Ironbound Mountain

Ironbound Mountain Formation of Seboomook Group (ME*,NH*,VT*)

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

Areal Extent:

Type Locality:
Along Pittston Farm-Rockwood Road, beginning at BM 1402, south to next 1402 BM. Named from mountain in Penobscot Lake quadrangle, Somerset Co., west-central ME (Pollock, 1987; Moench and others, 1995).

Grenier Ponds Grit Member (ME*)

Unit Name History:
First used (Marvinney, 1982, 1986; Pollock, 1987).
Overview (Marvinney, 1989; Marvinney, 1994).
Named; Extended into VT (Moench and others, 1995).
NH State Geol. Map usage; Extended into NH (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