A SEDIMENT ANALYSIS OF THE THREE DOG SITE (SS21), SAN SALVADOR ISLAND, COMMONWEALTH OF THE BAHAMAS

The Three Dogs Site (SS21) is the oldest known archaeological site within the Commonwealth of the Bahamas. The site, located on San Salvador Island, was excavated from 1984-1994. During excavation, soil samples were collected from the overburden, cultural, and subcultural layers of each excavation unit. The excavation revealed four distinct activity areas within the Three Dog Site: a midden, an “activity area,” a low density area, and a “house structure” (Berman et al. 1999, Latin American Antiquity). A full sediment analysis was conducted using these soil samples, to examine both physical and chemical variations within the site. The relatively pure calcium carbonate nature of the Bahamas presents this study with a unique opportunity to compare the concentrations of trace elements across the archaeological site.

Samples were analyzed for grain size, color, and for trace element concentrations. The concentrations of Al, Fe, Ni, Mg, P, Sr, and Ta were analyzed by ICP-MS. Using these data, we are able to isolate potential activity-specific anthropogenic signals within the archeological site. In order to distinguish between the signatures of the various horizons and activity areas, elemental concentrations were statistically discriminated using ANOVA. Elemental phosphorous, which is commonly associated with human activity, occurred at higher concentrations within the cultural horizons than the subculture horizons. Phosphorous within the cultural stratum showed elevated levels within the midden and activity area. Concentrations of Fe, Ni, and Al, which are most likely attributable to either the creation or usage of low-fired clay-based pottery, varied across the site. Al concentrations were found to be highest within the house structure. Fe concentrations were found to be highest in the midden. Higher quantities of Ni were found in the cultural unit than in the overburden and subculture. These data on the chemical anomalies, combined with the knowledge of the physical excavation of the site, will help develop a protocol for potential future chemical mapping of other archaeological sites within the Commonwealth of the Bahamas.