Differential diagenesis of sedimentary components and the implication for strontium isotope analysis of carbonate rocks

Geochemical analyses of various components (foraminifera, coccoliths and siliciclastic fractions) of limestone and marl samples from the marine Trubi Formation (Early Pliocene) of southern Italy revealed subtle diagenetic contamination. The coccolith fraction is altered from its original value both in its trace element (Sr/Ca, Mg/Ca, Fe/Ca, Mn/Ca, Na/Ca all were higher) and isotopic (87Sr/86Sr, δ18O, δ13C) composition. Coccolith 87Sr/86Sr …