Sulfur sedimentary

Evaporitic sulfur has a range of sulfur isotopic composition from +10%o to +30%o, while sedimentary sulfur is depleted in the heavy isotope and has a range of isotopic composition of about —40%o to +10%o. Most of this variation reflects systematic changes with geological age. The source fractions of a river water can be estimated from an isotopic mass balance ... 

Godfrey JD (1962) The deuterium content of hydrous minerals from the East Central Sierra Nevada and Yosemite National Park. Geochim Cosmochim Acta 26 1215-1245 Goericke R, Fry B (1994) Variations of marine plankton 6 C with latitude, temperature and dissolved CO2 in the world ocean. Global Geochem Cycles 8 85-90 Goldhaber MB, Kaplan IR (1974) The sedimentary sulfur cycle. In Goldberg EB (ed) The sea, vol. 4. WUey, New York... 

If iron limits retention of S in sediments (cf. 50, 30) it would be expected that the fraction of S present as iron sulfides would increase with increasing Fe content of sediments. Although this relationship is observed in deep sediments (Figure 7), fractionation of S between organic and inorganic forms is not determined by iron content in surface sediments. Nor is there any relationship between Fe content and total S content in surface sediments for all lakes reported in the literature (Figure lc). In deep sediments where C S ratios indicate that seston was the major source of sedimentary sulfur... 

Controls on Sedimentary Sulfur Chemistry. The variability of sulfur geochemistry in lacustrine environments is due, in part, to the large concentration... 

It is difficult to say from the 834S record of sedimentary sulfur-bearing minerals when the oceans accumulated significant oxidized sulfur. It is likely that the activity of photosynthetic green and purple sulfur-oxidizing bacteria produced the first free sulfate in the environment by reactions like... 

Garrels R.M. and Lerman A. (1984) Coupling of the sedimentary sulfur and carbon cycles-an improved model. Amer. J. Sci. 284, 989-1007. 

Bates, A.L., Spiker, E.C., and Holmes, C.W. (1998) Speciation and isotopic composition of sedimentary sulfur in the Everglades, Florida, USA. Chem. Geol. 146, 155-170. 

Strauss H. (1997) The isotopic composition of sedimentary sulfur through time. Palaeogeogr. Paleaoclimatol. Paleao-ecol. 132, 97-118. 

Table 3 Studies on sedimentary-sulfur geochemistry for selected depositional settings. 

For steady-state sedimentary processes, the isotopic composition of recent sedimentary sulfur and the reason for its large range of 8 values is primarily controlled by three factors (i) the magnitude of the instantaneous bacterial isotopic fractionation factor between S04 and... 

Figure 9 Plot of the sulfur isotopic composition of organic sulfur in marine sediments versus the sulfur isotopic composition of pyrite in the same sediments (reproduced by permission of American Chemical Society from Geochemical Transformations of Sedimentary Sulfur, 1994, 612, 378-396).

ROLE OF SEDIMENTARY SULFUR IN THE GLOBAL SULFUR CYCLE... 

Anderson T. F. and Pratt L. M. (1994) Isotopic evidence for the origin of organic sulfur and elemental sulfur in marine sediments. In Geochemical Transformations of Sedimentary Sulfur, American Chemical Society Symposium Series (eds. M. A. Vairavamurthy, M. A. A. Schoonen, T. I. Eglinton, and G. W. Luther, 111, B. Manowitz). American Chemical Society, Washington, DC, vol. 612, pp. 378-396. 

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