Differential Pollen Preservation in a Seventeenth-Century Refuse Pit, Jamestown Island, Virginia

Pollen that falls on soil surfaces is moved down through the deposit by percolating groundwater. As it moves, the pollen is progressively destroyed by oxygen in the groundwater and by aerobic fungi. In the Chesapeake Bay region, the deepest pollen in unsheltered archaeological site profiles is about 100 years old. A comparative study of a stratigraphic pollen profile exposed to the elements at the surface and a series of pollen samples sheltered by artifacts was conducted with materials from a 17th-century refuse pit at Jamestown, Virginia. Pollen was recovered both from under rocks and artifacts lying flat or concave side down and from around iron objects. The shallowest pollen spectrum recovered from under an artifact was 25 cm below the deepest pollen preserved in the exposed stratigraphic profile. No pollen was found in unsheltered pollen samples at the same depths as the artifacts. The distributions demonstrate that the pollen associated with the 17th-century artifacts is contemporaneous with those artifacts; it did not percolate down from later deposits. The artifact pollen spectra were arranged by depth into an artificial profile and appear to record a series of edaphic changes in the pit and a land-clearance episode in the Jamestown area.