A02_P04

Time varying Local Marine Reservoir Effect in Coastal Systems

Macario K¹, Alves E¹, Oliveira F¹, Chanca I², Scheel-Ybert R³, Gaspar M³, Tenorio C³, Dias F¹, Aguilera O¹, Bianchini G³, Vitorino B¹, Cardoso R¹, Anjos R¹, Muniz M¹

¹Universidade Federal Fluminense, Niteroi, Brazil, ²Max Planck Institute, Jena, Germany, ³Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil

The radiocarbon (¹⁴C) Marine Reservoir Effect (MRE) is known to vary with time due to global environmental changes, now better represented by the Marine20 calibration curve. In coastal regions, however, the scenario is considerably more complex and the MRE is influenced by carbon sources that exhibit a wide range of isotopic signatures. Indeed, the complexity of the carbon cycle in coastal systems demands extensive research for an accurate quantification of the MRE and its variability, which has the effect of hindering accurate ¹⁴C chronologies on the coast. The local MRE offset (∆R) in estuaries, is subject of the interplay of the hydrography with factors such as the regional geology, upwelling and sea-level variations. Using paired archaeological samples from the Southeastern coast of Brazil, we show a highly variable MRE and a possible correlation with the sea level regression.