Our new study tests whether Mg/Ca ratios measured with laser-induced breakdown spectroscopy (LIBS) can reveal when Indigenous communities in ancient Tampa Bay, Florida, harvested their oysters. Working with 20 archaeological eastern oysters (Crassostrea virginica) from shell mounds and middens in Bishop Harbor, we compared rapid LIBS elemental maps with traditional oxygen isotope (δ18O) analysis of the same shells.
Our new study delivers the most extensive calibration to date of Patella caerulea (the Mediterranean limpet) as a recorder of sea surface temperatures (SSTs) across the Central and Eastern Mediterranean. The study combined laser-induced breakdown spectroscopy (LIBS) for measuring Mg/Ca ratios with isotope ratio mass spectrometry (IRMS) to analyse oxygen isotope values (δ18O). By analysing 131 modern shells from 22 sites, we explored the relationship between magnesium-to-calcium (Mg/Ca) ratios and oxygen isotope values as palaeotemperature proxies.
This study presents a comprehensive calibration of the Patella caerulea as a palaeotemperature archive across the Central and Eastern Mediterranean, focusing on Mg/Ca ratios and δ^18^O values.