A02_P01

Direct and Indirect Attempts at Diachronic Quantification of the Marine Reservoir Effect

Niedospial J¹, Sevink J², Maurer A, Mazzini I⁴, Arienzo I⁵, Kuijper W⁶, van Hall R², Dee M¹

¹Centre for Isotope Research, University of Groningen, Groningen, Netherlands, ²Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands, ³Groningen Institute of Archaeology, University of Groningen, Groningen, Netherlands, ⁴Institute of Environmental Geology and Geoengineering, National Research Council of Italy, Rome, Italy, ⁵National Institute of Geophysics and Volcanology, Naples, Italy, ⁶Faculty of Archaeology, Leiden University, Leiden, Netherlands

The marine reservoir effect (MRE) is fundamental to understanding the carbon cycle and for correction of radiocarbon dates on samples either partially or wholly derived from marine carbon. Estimates of the offset commonly make use of paired samples of contemporary marine and terrestrial material, with the resultant offset then applied to the time period of interest. Paradoxically, it is widely accepted that the MRE at any one location is likely to have fluctuated over time, calling into question the validity of such retrojections. In this

study, we set out to both calculate the MRE for a specific location and then to understand the dynamics behind its variation over time using an array of geochemical and palaeoecological proxies. Previous research at our study site of Puntone, on the Tyrrhenian Sea, revealed that the area had transitioned between open marine, lagoonal and terrestrial regimes, and hence the local MRE was likely to have altered over time. This expectation was confirmed by the new radiocarbon data we obtained on marine shells and terrestrial plant remains. First attempts at using metal ion and isotope ratios through the core to elucidate, and indeed model, the MRE fluctuations have shown signs of promise but additional research is required to develop these approaches.