USGS Visual Identifier
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Geologic Unit: Hounsfield

Hounsfield Bentonite [Bed] of Selby Member of Rockland Formation (NY)
Hounsfield Metabentonite [Bed] of Selby Formation (NY)

Ordovician, Middle
Geologic Province:
Appalachian basin

Areal Extent:

Type Locality:
Type section: in small quarry just north of Dexter-Brownville Road at foot of west slope of hill, 2 mi east of Dexter, Jefferson Co., NY. [Named from adjacent Hounsfield Twp.] (Kay, 1930).

Unit Name History:
Named (Kay, 1930).
Areal limits (Kay, 1931).
Revised (Kay, 1937).
Areal limits (Conkin, 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
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Last modified: 15-Jan-2013