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Geologic Unit: Cockeysville

Cockeysville Marble (MD)
Cockeysville Marble of Glenarm Group (DE*,MD*,PA*)
Cockeysville Marble of Glenarm Supergroup (DE,MD,PA)

Proterozoic, Late
Geologic Province:
Piedmont-Blue Ridge province*

Areal Extent:

Type Locality:
Not designated. Named from exposures at Cockeysville, Baltimore Co., MD (Williams and Darton, 1892).
Reference section: outcrop in Eastburn's quarry, south of the intersection of Route 72 and Upper Pike Creek Road in Pleasant Hill Valley, Lat. 39 deg. 44 min. 25 sec. N., Long. 75 deg. 43 min. 03 sec. W., Newark East 7.5-min quadrangle, New Castle Co., DE (Plank and others, 2000).

Unit Name History:
Named (Williams and Darton, 1892).
Overview (Mathews, 1904; Miller and others, 1917).
Included in Glenarm series; Extended into PA (Knopf and Jonas, 1923).
Extended into DE (Bascom and Stose, 1932).
Revised (Stose and Stose, 1946).
Overview in DE (Rasmussen and others, 1957).
Age modified in PA (Gray and others, 1960).
Age modified in MD (Southwick and Fisher, 1967).
Age modified (Higgins, 1972).
Revised; Age modified (Crowley, 1976).
Age modified (Berg and others, 1983; Pavlides, 1989).
Revised (Drake and others, 1989; Gates, 1991).
Usage in PA and DE (Alcock, 1994).
Revised (Drake, 1994).
Overview; Reference section (Plank and others, 2000) [Not compiled yet. Publication available online from the Delaware Geological Survey: and].

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