CUR - The Council on Undergraduate Research

Radiocarbon Dating a Shipwreck

Marissa Agerton, Dr. John Bratten, Department of Anthropology, University of West Florida, 11000 University Parkway Pensacola, FL 32514

The Emanuel Point ship sank in 1559 along with five other ships in the Pensacola Bay area due to a hurricane. These ships were part of Don Tristán de Luna y Arellano‘s Spanish fleet that colonized Pensacola, Florida. This is the earliest known multi-year European settlement in the United States. The wreck was discovered in 1992 by the state of Florida and excavated by the University of West Florida (UWF) archaeology students until 1998. A wood sample collected from the shipwreck will undergo conservation and documentation before being radiocarbon dating. To stabilize the artifact, it will be freeze-dried to remove all water, allowing for a more accurate Carbon-14 result. By sending a sample, we will be able to determine if wood that has been waterlogged for more than 450 years is datable. It is possible that organic debris associated with the bay water may have contaminated the sample and may alter test results because they have their own Carbon-14 isotope ratios. Because the artifact is wood, the sample that is chosen for testing may have been harvested from a very old tree; therefore it may also be affected by a factor known as the “old wood effect.” Another possible factor is that carbon emission did not stop at the time the wood was cut so the radiocarbon age of “death” cannot be assumed to be zero like most other materials that undergo radiocarbon dating. Only after completing the radiocarbon test will we be able to answer whether or not these scenarios affect the results and to what degree. This data will be able to provide future comparison to other sites that are radiocarbon dated such as the other two shipwrecks that have been associated with this fleet and its colony site. 

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