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Geologic Unit: Beekmantown

Beekmantown Dolomite (NY*,PA*,VA*,WV)
Beekmantown Limestone (MD*,PA*,NY*,VA*)
Beekmantown Shale (NY*,VT*)
Beekmantown Formation (VA)
Beekmantown Dolomite of Knox Group (VA*,WV)
Beekmantown Group (MD*,PA*,NJ*,VA*,VT*,WV*,NY*,OH*)
Beekmantown Group of Kittatinny Supergroup (NJ*,PA*)
Beekmantown Group of Knox Supergroup (OH)
Beekmantown Formation of Knox Group (VA)

Cambrian, Late
Ordovician, Early*
Ordovician, Middle*

Geologic Province:
New England province*
Appalachian basin*

Areal Extent:

Type Locality:
Exposures at Beekmantown, Clinton Co., northeastern NY (Clark and Schuchert, 1899).
Reference section: begins at top of group in Potomac River bluff, about 1000 ft west of intersection with southwest face of Pinesburg Station quarry, and continues westward along C&O Canal for 1 mi, Washington Co., MD (Sando, 1956).

GROUP STATUS (alphabetical): Axemann Limestone (PA*), Axemann Formation (PA), Bascom Formation (VT*), Beldens Formation (VT*), Bellefonte Dolomite (PA*), Bellefonte Formation (PA), Bridport Dolomite (NY), Chepultepec Dolomite (TN, OH, KY), Chipman Formation (VT*), Chuctanunda Creek (NY), Cutting Dolomite (VT*), Cutting Formation (VT), Epler Formation (PA*,NJ*), Fort Ann Formation NY), Fort Cassin Formation (VT,NY), Great Meadow Formation (NY), Hastings Creek Limestone (VT), Highgate Formation (VT), Larke Dolomite (PA*,NY), Larke Formation (PA,WV), Luke Hill Limestone (VT), Morgan Corners Formation (VT), Naylor Ledge Limestone (VT), Nittany Dolomite (PA*,MD*), Ogdensburg Dolomite (NY), Ontelaunee Formation (PA*), Pinesburg Station Dolomite (MD*,VA*,WV*), Pinesburg Station Formation (PA*), Potsdam Sandstone (NY), Providence Island Dolomite (VT), Rickenbach Dolomite (NJ*,PA*), Rickenbach Formation (NJ,PA), Rockdale Run Formation (MD*,PA*,VA*,WV*), Rose Run Sandstone (OH), Shelburne Formation (VT*), Spellman Formation (NY), Stonehenge Limestone (PA*,MD*,VA*,WV*,NJ*,NY*), Stonehenge Formation (PA*,NJ*,NY*), Stoufferstown Formation (PA), Strites Pond Formation (VT), Tribes Hill Formation (NY), Wallace Creek Formation (VT), Whitehall Formation (NY,VT), Whitehall Dolostone (VT).

FORMATION STATUS (alphabetical): Chepultepec Dolomite Member (VA), Kingsport Dolomite Member (VA), Longview Dolomite Member (VA), Mascot Dolomite Member (VA).

Unit Name History:
Named Beekmantown Limestone (Clark and Schuchert, 1899).
Revised in NY (Cushing, 1908).
Revised (Grabau, 1909).
Revised in NY (Kemp and Ruedemann, 1910).
Revised (Ulrich and Cushing, 1910).
Overview (Butts, 1940, 1945; Swartz, 1948).
Extended into WV (Woodward, 1951).
Revised (Sando, 1956).
Revised in PA (Hobson, 1957).
Overview (Welby, 1959; Cady and Zen, 1960; Doll, 1961).
Extended into OH (Calvert, 1962).
Revised in VA (Milici, 1963).
Extended into NJ (Stevens, 1963).
Overview (Drake, 1965).
Revised in NY (Shaw, 1968).
Revised in VA (Miller and Meissner, 1977).
Age modified (Harris and Harris, 1978).
Revised in PA and NJ (Drake and Lyttle, 1980).
Overview (Fisher, 1984).
Revised in WV (Sweeney, 1986).
Revised to formation of Knox Group (Kulander and Dean, 1986).
Overview (Coogan and Maki, 1988).
Revised in VT (Washington and Chisick, 1988).
Overview (Thompson, 1990).
Revised (Ryder, 1992).
Age modified in OH (de Witt, 1993).

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