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Geochemical and Sr, Nd, Pb, O and C isotopic data are reported for 13 carbonatites from Africa, Australia, Brazil, Europe and the United States. The carbonatites possess generally high Ba, Th, LREE, Sr and low Cs, Rb, K and HREE abundances. Some examples have low Ti, Nb, Ta, P, Zr, Hf and U concentrations which are consistent with variable fractionation of sphene, apatite, perovskite, monazite or zircon. The samples range in age from Proterozoic to Tertiary and possess a range of initial Sr isotopic compositions between 0.7020 and 0.7054, initial ϵ_Nd values of −0.4 to +3.8 and (with the exception of the Brazilian Jacupiranga carbonatite) generally radiogenic initial Pb isotopic compositions. δ¹⁸O_SMOW compositions of the intrusive carbonatites range from +5.5 to +12.4‰ Higher δ¹⁸O_SMOW values of +14 and +17%. are found in the volcanically-emplaced Proterozoic Goudini complex of South Africa …