This dataset contains data and metadata of the calcareous soil collection used in the EJP-Soil SIC-SOC-DYN project. This dataset is linked to 2 articles submitted for publication into Biogeosciences journal and into Journal of Arid Environment Data focused on the characterisation of the organic and inorganic carbon of calcareous soils obtained by elemental analysis, by Rock-Eval® thermal analysis and by isotope ratio mass spectrometer. The Publication submitted into Biogeosciences is entitled "Technical note: Further adjustments to the Rock-Eval® thermal analysis for soil organic and inorganic carbon quantification to avoid post-hoc corrections" and focused on Rock-Eval data. The Publication submitted into Journal of Arid Environment is entitled "Analytical distinction between soil organic and inorganic carbon contents and 13C natural abundances: Evaluation of a heating pretreatment" and focused on isotopic data.