Rick J Schulting

RICK J. SCHULTING, University of Oxford, Oxford, United Kingdom, was awarded a grant in October 2016 to aid research on ‘Sourcing the Ancient Canoes of Florida’s Wetlands.’ The project sought to develop a means of sourcing the many prehistoric canoes that have been recovered in Florida’s waterways, using strontium isotope (87Sr/86Sr) analysis. While previous research had suggested the viability of this approach, concerns were raised when initial results obtained on submerged canoes recovered from Newnans Lake, north-central Florida, indicated a persistent influence from strontium deriving from both lake water and the water used in the Florida Natural History Museum’s conservation laboratory. Substantial efforts were therefore directed at experiments designed to test different methods of removing exogenous strontium from submerged woods. To date, the results have yielded only limited success. A second major aim of the project was to better characterize the biologically available strontium values across central and northern Florida, where many of the canoes have been found. The available bedrock maps for Florida guided our sampling strategy. We now have 92 measurements on modern trees from 78 locations, and it is apparent that there is considerably more variability than expected, and that this variability shows only limited spatial patterning. While trees growing close to bedrock near major watercourses have distinct values in or near the anticipated range, those only a few meters (or tens of meters, depending on the local topography) distant can have substantially different values, reflecting the influence of Pliocene to Holocene cover sands. This is an important finding, though it does present a further challenge in terms of sourcing the canoes. Additional experimental research will be undertaken as a legacy of this project, and a strontium isoscape for northern Florida will be created.