These cores were collected during the winter season in August 2017 using Russian-type sampling equipment. Sediment cores were obtained from tidal flats colonized by mangroves (SF-07, SF-08), herbs (SF-09), and ombrophilous forest (SF-10). All samples were combusted in the benzene synthesis line, transformed to CO2 and encapsulated at the 14C Laboratory of CENA. Sedimentation rates were estimated using the sample depths and time intervals. The CO2 samples were analyzed at the AMS Radiocarbon Laboratory (UGAMS), Center for Applied Isotope Studies, University of Georgia, Georgia, USA. Radiocarbon ages were normalized to a δ13C of −25‰ VPDB and reported as calibrated years (cal yr BP) (2σ).