| Abstract: |
Oxygen isotopes (d18O) derived from archaeological Mercenaria campechiensis shells and Ariopsis felis otoliths potentially provide low latitude paleoclimate data for studying Late Holocene humanclimate interactions in coastal southwest Florida. Specimens analyzed come from the Pineland site complex. Deposits record abrupt and subtle environmental changes appearing to have been climate-related and to have impacted the sedentary human residents. One archaeological shell-otolith set dates to 2nd/3rd century A.D. within the Roman Optimum (RO) climatic episode. A second set dates to 13th/14th century A.D. within the Little Ice Age (LIA). A modern shellotolith set was analyzed for comparison. d18OARAGONITE of modern and LIA shells suggest similar seasonal conditions. RO shell is 1% more positive during summer, suggesting higher estuarine salinity than in modern and LIA times. Modern and LIA otoliths also have similar d18OARAGONITE. Estimated Winter temperatures are within measured instrument records. Summer temperatures are overestimated reflecting Summer migration into less-saline water. Estimated Summer temperatures for RO otolith are similar to todays, suggesting elevated estuarine salinity and diminished rainy season, consistent with similar aged zooarchaeological assemblages. Comparisons of two taxa aid in interpreting archaeological d18O data
however, early results are mixed with expected profiles for RO specimens and unexpected profiles for LIA specimens.
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