Holocene Paleoclimate Reconstruction from δ18O Isotopes of Neocyclotus Opercula a Morphometric Analysis of Variation at the Archaic Site of San Jacinto1 Colombia

Summary

Neocyclotus snails produce opercula, a calcified plate attached to the foot of the gastropod serving as a protection mechanism from predators, and dehydration. Opercula are rarely found in the archaeological record, and have only been recovered from few archaeological contexts. Excavations at the Archaic site of San Jacinto, Colombia have facilitated the unprecedented recovery of 3,542 opercula a presence that has not been recorded previously in the neotropics. These calcified plates form calcareous layers, which halt growth during yearly dry seasons, and are useful as markers for seasonality of deposition. The isotopic data from opercula samples is superior to that of shells as they display less natural variability, and preserve intra-crystalline proteins due to the greater stability of calcite. The particular characteristics in opercula make these structures ideal for analysis of stable isotope variability (δ18O) to infer seasonal variation. A random sample of the San Jacinto opercula was analyzed to determine spatial attributes, taxonomy, morphometrics, and human-modifications. Said analyses allow us to infer the opercula’s function at the site, and determine the variation as well as the conservation of opercula samples for a future stable isotope analysis as a proxy for Paleoclimatic variation in Northern Colombia during the middle Holocene.

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This Resource is Part of the Following Collections

• Society for American Archaeology 80th Annual Meeting, San Francisco, CA (2015)   •
• Recent Doctoral Research on Colombian Archaeology

Keywords

Spatial Coverage