PROXIES OF PALEOCLIMATE FROM ARCHAEOLOGICAL MIDDEN SHELLS, ATLANTIC COAST, DOMINICAN REPUBLIC

Geochemical analysis of shell midden materials remains limited for much of the archaeological investigations into the Taíno peoples of the Caribbean. We investigate shells from the historically important El Tamarindo archaeological site in order to initiate the establishment of a time line in which to place data relating to Atlantic Ocean, shallow-water sea surface temperatures of the recent past. The El Tamarindo site contained 29 species of Bivalvia and 42 species of Gastropoda, with 2,242 bivalve and 3,387 gastropod individuals represented. This study utilizes valves of Crassostrea virginica that represented 14.5% of the minimum number of bivalve and gastropod individuals at El Tamarindo. The calibrated ages of three oyster valves from El Tamarindo indicate an average calendar date of 1397 AD and a range from 1361-1454 AD. Stable carbon and oxygen isotope analyses of the Crassostrea virginica valves yield paleoclimate proxies for ambient estuarine waters near the El Tamarindo site. Our paleoclimate data from 22 samples obtained from three valves yield data for two valves that share an average value of -1.8 d18O and the third valve that has an average value of -1.4 d18O. Further investigations into the ancient estuarine conditions from the site require unraveling of the variables that influence the carbon and oxygen isotopic ratios used for paleoclimate proxies. The resulting isotopic record will facilitate inference of important abiotic parameters that controlled growth and reproduction in molluscs and will allow for characterization of paleoclimate patterns on the Atlantic northwestern coast of the Dominican Republic.