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RESEARCH PRODUCT

Isotopic composition of dissolved sulphate and hydrogen sulphide from some thermal springs of Sicily

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description

Samples of some thermal springs from Sicily have been analysed for the isotopic composition of sulphur-bearing species. The values of δ34S(SO42− (range: +7.3, +31.7‰), δ34S(H2S) (range: −12.2, +27.8), δ34S(S°) (range: +1.9, +24.5) and δ18O(SO42−) (range: −2.5, +23.9) obtained show such a remarkable variability in data as to hypothesize different genetic processes concerning these species. Furthermore, from the available experimental data, the relationship between the isotopic composition of the sulphur in the dissolved sulphate and in the associated hydrogen sulphide (ΔSO42− - H2S = 25 – 30‰) seems to indicate the bacterial reduction of sulphate ion as one of the processes most significantly influencing the isotopic geochemistry of sulphur.