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 on our Links page.

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