Radiocarbon Dates
Radiocarbon dating provides a way to determine the age of archaeological deposits and associated artifacts. Carbon samples, most often charcoal or burnt encrustations on ceramic vessels, are carefully collected from an excavation. The amount of radioactive Carbon 14 isotope present in the sample is measured to calibrate how much time has gone by since the material was burnt.
Carbon is found in every living organism and is absorbed from the atmosphere. When a plant or animal dies, the amount of carbon isotopes begin to decay at a known and constant rate. By measuring the radioactive Carbon14 (C14) concentrations, the time of the organism's death can be estimated. For a more in-depth explanation of how radiocarbon dating works, you may want to visit the websites listed below.
While creating this webpage on Maryland's diagnostic artifacts, we compiled a database of radiocarbon dates that have been produced over the last 30 years in Maryland and surrounding states. Newer methods of processing samples and calibrating the dates have brought many previously-run dates into question. Some of these dates may be inaccurate due to the length of time since they were processed and the integrity of the data concerning associated artifacts, for example, shell is sometimes used as a sample for radiocarbon dating, and these dates are often less reliable than those run on burnt wood.
For these tables, we have attempted to present only the most reliable, emphasizing those most recently obtained, in actual association with the ceramic wares and from Maryland sites. We plan to continue to refine these tables and to add new information as it becomes available.
Marcey Creek / Dames Quarter / Selden Island / Accokeek / Wolfe Neck / Popes Creek / Coulbourn / Watson / Mockley / Clemson Island / Page / Shepard / Townsend / Sullivan Cove / Moyaone / Potomac Creek / Keyser / Yeocomico
| Marcey Creek | ||||
|---|---|---|---|---|
| Date | Sample No. | Site | Feature | Reference |
| 2900 ± 95; 950 B.C. | I-5091 | Monocacy (18FR100) | Zone 5 | Ayers 1972 |
| 2495 ± 95; 545 B.C. | I-5090 | Monocacy (18FR100) | Zone 5 | Ayers 1972 |
| Dames Quarter | ||||
|---|---|---|---|---|
| Date | Sample No. | Site | Association | Reference |
| 2955 ± 90; 1005 B.C. | UGa-5376 | Clyde Farm, DE | Dames Quarter ceramics | Custer, Watson and DeSantis 1986 |
| Selden Island | |||
|---|---|---|---|
| Date | Sample No. | Site | Reference |
| 2955 ± 90; 1005 B.C. | UGa-5376 | Clyde Farm, DE | Custer, Watson and DeSantis 1986 |
| Clemson Island | |||||
|---|---|---|---|---|---|
| Date | Sample No. | Site | Feature | Associated Material | Reference |
| 940 ± 65; AD 1010 | SI-6447 | Paw Paw (18AG144) | Feature 3 | Crushed rock/chert/mixed temper pottery | Kavanagh 1984 |
| Potomac Creek | |||||
|---|---|---|---|---|---|
| Date | Sample No. | Site | Feature | Associated Material | Reference |
| 350 ± 30; A.D. 1520/1570/1630 | Beta-104595 | Potomac Creek (44ST2) | Potomac Creek | Blanton et al. 1999 | |
| 410 ± 50; A.D. 1460 (intercept date) | Beta-102324 | Potomac Creek (44ST2) | Potomac Creek | Blanton et al. 1999 | |
| 540 ± 60; A.D. 1415 (intercept date) | Beta-102323 | Potomac Creek (44ST2) | Potomac Creek | Blanton et al. 1999 | |
| 670 ± 60; A.D. 1300 (intercept date) | Beta-102325 | Potomac Creek (44ST2) | Potomac Creek | Blanton et al. 1999 | |
| 375 ± 90; A.D. 1575 | Data-13560 | IH-35 (18CH281) | Dent 1995: 246 | ||
References
1976 An Overview of the proposed ceramic sequence for southern Delaware. Maryland Archeology 12 (2): 1-15.
1972 The Archaeology of the Susquehanna Tradition in the Potomac Valley. Doctoral dissertation, Department of Anthropology, The Catholic University of America at Washington, D.C. University Microfilms International, Ann Arbor, MI.
1975 Preliminary Notes on the Results of the Fifth Annual Maryland Archeological Field Session. Archeological Society of Maryland, Inc., Newsletter 21 (6): 2-4.
1999 The Potomac Creek Site (44ST2) Revisited. Virginia Department of Historic Resources Research Report Series No. 10. Prepared by the William and Mary Center for Archaeological Research, The College of William and Mary, Williamsburg.
1966 University of Michigan Radiocarbon Dates XI. Radiocarbon 8: 256-285.
1991 The Middle to Late Woodland Transition in Maryland. North American Archaeologist 12 (1):2-28.
1993 A New Radiocarbon Date for Popes Creek Ware. Maryland Archeology 29 (1 and 2):31-42.
1986 Archaeological Investigation of the Churchman’s Marsh Area. University of Delaware Center for Archeological Research Monograph No. 5. Newark, Delaware.
1995 Chesapeake Prehistory: Old Traditions New Directions. Plenum Press, New York.
1990 Preliminary Report of Archaeological Investigations at the Hughes Site. Potomac River Archaeological Survey, Department of Anthropology, American University, Washington, D.C.
1982 Prehistoric Ceramics in Delaware (An Overview). Archaeology of Eastern North America 10: 46-68.
1977 Middle Woodland Ceramics from Wolfe Neck, Sussex County, Delaware. The Archeolog 28 (1): 1-28.
1974 The Middle Woodland in the Middle Atlantic: Chronology, Adaptation, and Continuity. Paper presented at the 5th Middle Atlantica Archaeological Conference, Baltimore.
1984 Phase II Archeological Investigations at the Paw Paw Site (18AG144) Allegany County, Maryland. Maryland Geological Survey, Division of Archeology Field Report No. 183.
1986 Technical Report of the Archeological Investigations for the Solomons Island/Appeal Sewage Treatment Project, Calvert County, Maryland. Prepared for Calvert County Department of Public Facilities and Services.
1996 Archaeological Survey Work on Maryland's Eastern Shore During the 1996 Field Season. Report on file at the Maryland Historical Trust, Crownsville.
1991 Phase III Archaeological Investigation of the 522 Bridge Site 44WR329 Warren County, Virginia. Virginia Commonwealth Archaeological Research Center, Richmond, VA.
1985 Excavations on Locust Neck: The Search for the Historic Indian Settlement in the Choptank Indian Reservation. Journal of Middle Atlantic Archaeology, 1: 87-95.
1978 Preliminary Test Excavations at the Waveland Farm Site (18AN17), Anne Arundel County, Maryland. Maryland Archeology, 14 (1-2): 17-23.
1982 An analysis of Chicacoan settlement patterns. Dissertation. University of North Carolina, Chapel Hill.
1983 Archaeological Investigations at the Moore Village Site. National Park Services, Denver Service Center.
1989 A Preliminary Archaeological Data Base for the Maryland Coal Region. Maryland Historical Trust, Crownsville.
1993a Phase III Data Recovery Excavations: Sites 18AG167 and 18AG168. Prepared for the Federal Bureau of Prisons by Louis Berger and Associates, Inc.
1993b Stratigraphy and Sequence in the South Branch of the Upper Potomac Valley, Moorefield and Petersburg, West Virginia. Journal of Middle Atlantic Archaeology 9: 49-66.
2001 Late Woodland Ceramics and Native Populations of the Upper Potomac Valley. Journal of Middle Atlantic Archaeology 17:15-37.
1982 Shellfish Gathering and Shell Midden Archaeology. Doctoral dissertation, Department of Anthropology, University of North Carolina at Greensboro, North Carolina. University Microfilms International, Ann Arbor, MI.
1973 The Piscataway Site: A Stratified Woodland Site in Tidewater Maryland (18PR7) Prince George’s County, MD. Manuscript on file, Maryland Historical Trust, Crownsville, MD.