One of the challenges of the study of geological samples in the oil and gas industry is obtaining mineralogical properties of the rocks, from the thin section scale up to rock core. m‐XRF (X-Ray Fluorescence) scan of thin sections can be used as a very quick compositional screening tool that facilitates the preliminary definition of the sedimentological facies and diagenetic textures and processes by different element/minerals distribution. The integration of core observations and m‐XRF multi-element overlay images has permitted a quick preliminary sedimentological facies definition and the recognition of several diagenetic processes as dolomitization and/or silica levels in carbonate samples. Further XRD and SEM-EDS and bulk rock stable isotope C and O analysis have confirmed those sedimentologic and diagenetic interpretations. The core observation and the multi element overlay images generated by m‐XRF allowed the identification of 2 main sedimentology facies in carbonate samples: (1) Crinoidal–bryozoan rich grainstone-packstone and (2) Dolo-mudstone-wackestone. Other features identified with the m‐XRF images include calcite and silica cementation and replacement, dolomitization, stylolites, distribution of clay minerals, presence of evaporite minerals and sulphides.