Trace element analysis (Mg, Sr, Na, K, Mn, Fe, Ni, Cr, and Zn) of CYAMAZ carbonates shows that a geochemical characterization of platform and post-platform sediments is possible. Platform sediments geochemical study leads to precise the paleoenvironment and shows that late oceanic diagenesis (which take place after subsidence of the platform) does not alter trace element contents of rocks. An attempt of geochemical dating (chemostratigraphy) of post-platform sediments is made.