Highly-resolved radiocarbon measurements on shells from Kalba, UAE, using carbonate handling system and gas ion source with MICADAS

The Mini Carbon Dating System (MICADAS) represents a flexible AMS system for measuring radiocarbon samples either in the form of graphite or CO2 gas. We used the possibility to attach a carbonate handling system (CHS) to the gas ion source (GIS) to measure smaller amounts of carbonates ( 3) are used to clean the system. We tested the CHS-GIS combination on heated and unheated archaeological shells of Anadara uropigimelana from Kalba, Sharjah Emirate, United Arab Emirates (UAE). Even though the amount of carbon in the samples was small (4–22 µg C) the performance of the CO2 dating system permits the comparison of trends in the 14C data to stable isotope measurements (δ18O and δ13C). With 10–20 µg C, however, our sample sizes were too small, suffering from cross-contamination and elevated blanks, and our blank samples prior to the small samples were not enough. Hence, an interpretation in combination with the stable isotope data was not possible beyond comparison of trends.