The data refer to the geochemical and isotopic characterization of sandstones, with carbonate cementation (beach rocks), and hybrid carbonates, formed by algal mats, in the shallow platform of the South Atlantic Ocean, Espírito Santo - Brazil. The determination of 14C activity was performed on 10 samples in Accelerator Mass Spectrometry Dating (AMS), University of California, Irvine (UCL). Sample preparation backgrounds have been subtracted based on measurements of 14C-free calcite. Radiocarbon concentrations were given as fractions of the modern standard, δ14C, and the conventional radiocarbon age followed the convention of Stuiver and Polach (1977). The 14C calibration was performed on the Radiocarbon Calibration Program* CALIB REV7.1.0, Copyright 1986-2018 (Stuiver and Reimer, 1993), with marine13.14C calibration dataset (Reimer et al., 2013). The concentrations of rare earth elements (REEs) and traces were obtained by ICP-MS (PerkinElmer Nexlon300D), after digestion according to the modified EPA Protocol 3052. The quality of data was checked by the analysis of standard reference material (PACS-2 National Research Council, Canada).

The study was carried out between 2017 and 2021 on the coast of Espírito Santo, specifically on the beach of Parati, municipality of Anchieta, in sandstones and hybrid carbonates, with the objective of analyzing the depositional dynamics throughout the Holocene. The occurrence of hybrid sandstones and carbonates in the intertidal zone is uncommon in the region, configuring an excellent proxy for the reconstitution of relative variations in sea level and paleoclimate.Radiocarbon concentrations are given as fractions of the Modern standard, D14C, and conventional radiocarbon age, following the conventions of Stuiver and Polach (Radiocarbon, v. 19, p.355, 1977). Sample preparation backgrounds have been subtracted, based on measurements of 14C-free calcite. All results have been corrected for isotopic fractionation according to the conventions of Stuiver and Polach (1977), with d13C values measured on prepared graphite using the AMS spectrometer. These can differ from d13C of the original material, and are not shown.These samples were leached 50% with dilute HCl prior to hydrolysis with 85% phosphoric acid. Duplicate samples of P1F118 gave significantly different results, as did carbonate cement and an embedded gastropod and bivalve from P2F418. d13C values shown above were measured to a precision of <0.1‰ relative to standards traceable to PDB, using a Thermo Finnigan Delta Plus stable isotope ratio mass spectrometer (IRMS) with Gas Bench input. The initial P1F118 cement and P2F418B bivalve samples were too small to provide an additional CO2 aliquot for IRMS analysis.