USGS Visual Identifier
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Geologic Unit: Antietam

Antietam Formation of Chilhowee Group (VA*,MD,PA,WV)
Antietam Quartzite of Chilhowee Group (MD*,PA*,VA*,WV*)
Antietam Schist of Chilhowee Group (MD*,PA*)
Antietam Sandstone of Chilhowee Group (MD*,PA*,VA*)

Cambrian, Early*

Geologic Province:
Appalachian basin*

Areal Extent:

Type Locality:
Exposures near Antietam Creek, north of Potomac River, Washington Co., western MD (Keith, 1893).

Unit Name History:
Named Antietam Sandstone (Keith, 1893).
Overview as Antietam Quartzite (Stose and Stose, 1946).
Described in WV (Woodward, 1949).
Described in VA; Revised (King, 1950).
Described in PA (Chapman, 1950).
Areal limits (Cloos, 1951).
Areal limits; Overview (Scotford, 1951).
PA Geol. Survey usage (Gray and others, 1960).
Age modified (Hack, 1982).

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