USGS Visual Identifier
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Geologic Unit: Cobourg

Cobourg Limestone (NY*)

Ordovician, Middle*
Geologic Province:
Appalachian basin

Areal Extent:

Type Locality: (See Canadian Lexicon)
Cobourg, Northumberland Co., Ontario, Canada (Raymond, 1921).

Unit Name History:
Named (Raymond, 1921).
Extended into NY; Revised (Kay, 1933).
Revised (Kay, 1937, 1943).
Revised (Fisher, 1961, 1962).
Revised; Age modified (Fisher and others, 1968).
Not used (Kay, 1968).
Age modified (Isachsen, 1970; Johnson, 1970; Ross, 1970; Rickard, 1973).
Not used, restricted to Canada (Fisher, 1977).
Overview (Frey, 1995).

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