[SMP37-P03] Multiple sulfur isotope geochemistry of the Precambrian mafic dyke swarms in the Dharwar craton, South India.
Keywords:Archean, Sulfur isotopes, Mafic dyke swarms, Mass Independent Fractionation (MIF)
In the current study, the mafic dyke swarms in the Dharwar craton are considered. A detailed geochemical characterization of the dykes were carried out, including Sr and Nd isotopic composition. The results indicate a prominent enriched mantle component in younger paleoproterozoic dykes, whereas older Archean dykes preserve primitive mantle signatures . Reconnaissance analysis of representative dyke of various ages have been carried out for the multiple sulfur (δ34S, Δ33S and Δ36S) isotope composition. δ34S for all the samples were negative, whereas Δ33S and Δ36S shows only nominal, but distinct variations. The samples are showing a scattered distribution in the variation diagrams of both δ 34S versus Δ33S and Δ33S versus Δ36S and are suggesting a mantle signature in most cases. The distribution of the multiple sulfur isotope and their relative abundances in the form of Δ33S, δ34S, and Δ36S leads to a better understanding of the Archean sulfur reservoirs and the possible isotopic fractionation in the deep earth. Further detailed studies are ongoing, and we present a comprehensive evaluation of recycling vs. mantle components in the Archean to Paleoproterozoic lithospheric mantle beneath the Dharwar craton.
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