Sulphur isotopes fractionation

Rees CE (1973) A steady-state model for sulphur isotope fractionation in bacterial reduction processes. Geochim Cosmichim Acta 37 1141-1162... 

Fig. 2.21 Rayfeigh plot for sulphur isotopic fractionations during the reduction of sulfate in a closed system. Assumed fractionation factor. 1.025, assumed starting composition of initial sulfate ...

McCready RGL (1975) Sulphur isotope fractionation by Desulfovibrio and Desulfotomaculum species. Geochim Cosmochim Acta 39 1395-1401 McCready RGL, Kaplan IR, Din GA (1974) Fractionation of sulfur isotopes by the yeast Saccha-romyces cerevisiae. Geochim Cosmochim Acta 38 1239-1253 McDermott F (2004) Palaeo-cUmate reconstruction from stable isotope variations in speleothems a review. Q Sci Rev 23 901-918... 

Szaran J., Niezgoda H., and Halas S. (1998) New determination of oxygen and sulphur isotope fractionation between gypsum and dissolved sulphate. RMZ-mater. Geoenviron. 45, 180-182. 

Habicht K. S. and Canfield D. E. (1996) Sulphur isotope fractionation in modern microbial mats and the evolution of the sulphur cycle. Nature 382(6589), 342-343. 

Krouse, H.R., McCready, R.G.L., Husain, S.A. and Campbell, J.N., 1968. Sulphur isotope fractionation kinetic studies of sulfite reduction in growing cells of Salmonella Heidelberg. Biophys. J., 8 109—124. 

Smejkal, V., Michalicek, M. and Krouse, H.R., 1971b. Sulphur isotope fractionation in some springs of the Carpathian mountain system in Czechoslovakia. Cazs. Mineral. Geol., 16 275—283. 

Solomon, P.J. and Jensen, M.L., 1965. Sulphur isotopic fractionation in nature with particular reference to Mt. Isa, Queensland. Proc. Eighth Commonwealth Min. Metall. Congr., 6 1275-1286. 

Wortmann, U., Bernasconi, S.M., and Bottcher, M.E., 2001. Hypersulfidic deep biosphere indicates extreme sulphur isotope fractionation during single-step mircrobial sulphate reduction. Geology, 29, 647-50. 

Another major increase in atmospheric 02 may have occurred towards the end of the Proterozoic (Knoll et al. 1986 Derry et al. 1992 Des Marais et al. 1992), providing the opportunity for more complex, multicellular eukaryotes to evolve. Further evidence for such an increase is provided by the isotopic record of sedimentary marine sulphides (Canfield 1998 see Box 1.13). From c.2.3 to between 1.05 and 0.64 Ga the sulphur isotopic fractionation was <4%o with respect to marine sulphate, suggesting low sulphate levels, consistent with limited oxygenation of the atmosphere and surface waters, sufficient to allow enough oxidation of sulphide to sulphate for the use of sulphate-reducing bacteria in deeper anoxic environments. Enough sulphide may have been produced by these bacteria to remove dissolved iron(II) as pyrite. So for a large part of the Proterozoic bottom waters remained anoxic and sulphidic... 

Eiler JM, Kitchen N, Rahn TA (2000) Experimental constraints on the stable-isotope systematics of CO2 ice/vapor systems and relevance to the study of Mars. Geochim Cosmochim Acta 64 733-746 Elcombe MM, Hulston JR (1975) Calculation of sulphur isotope fractionation between sphalerite and galena using lattice dynamics. Earth Planet Sci Lett 28 172-180 Emiliani C (1955) Pleistocene paleotemperatures. J Geol 63 538-578... 

Thode HG, Kleerekoper H, McElcheran DE (1951) Sulphur isotope fractionation in the bacterial reduction of sulphate. Research London 4 581-582... 

Sulphur isotope fractionations In an igneous melt are small and take place either between crystals and melt or through solid-gas fractionation. fractionation between primary sulphide minerals and magma is of the order of 1-3 / (Ohmoto and Rye, 1979 Chaussidon et aL, 1989). Differentiated felsic and mahc sequences record a maximum decrease in of 1 "/m (Ueda and Sakai, 1984). 

An alternative means of sulphur isotope fractionation in igneous rocks is by the degassing of SO2 from sub-aerial or shallow submarine lavas. This fractionation is controlled by the sulphate/sulphide ratio of the melt, which in turn is controlled by temperature, pressure, water content and oxygen activity. SO2 outgassed by basic lavas is enriched m relative to die melt because the dominant sulphur species in the melt is sulphide and SO2 is enriched in 5 S relative to sulphide (see Figure 7.26). The process is documented from Kilauea volcano, Hawaii, by Sakai el al (1982) and quantified by 2heng (1990). 

Figure 7.23 The sedimentary sulphur cycle showing the pattern of sulphur-isotope fractionation in sedimentary and hydrodiermal processes.

Sulphur isotope fractionation between sulphide and sulphate phases — sulphur isotope thermometry... 

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