Results 221 to 230 of about 20,788 (267)

The Selective Flux of Sulfur and Implications for Magmatic Sulfur Isotope Fractionation

Isotopes in Environmental and Health Studies, 1990
The selective flux of sulfur during magma emplacement is proposed to explain some abnormal δ34S data from granitic and basaltic rocks. It is assumed that on the one hand a quasi-equilibrium isotope fractionation exists between sulfate and sulfide during magma cooling, and on the other hand a non-equilibrium fractionation occurs between the fluxed ...
exaly   +2 more sources

Microscale reservoir effects on microbial sulfur isotope fractionation

Geochimica Et Cosmochimica Acta, 2017
Abstract Microbial sulfate reduction can impart strong sulfur isotope fractionation by preferentially using the lighter 32 SO 4 2 - over the heavier 34 SO 4 2 - . The magnitude of fractionation depends on a number of factors, including ambient concentrations of sulfate and electron donors.
Stilianos Louca, Sean A Crowe
exaly   +2 more sources

Fractionation of Sulfur and Carbon Isotopes in a Meromictic Lake

Science, 1963
In the permanently stagnant depths of Green Lake (near Syracuse, N.Y.), sulfide made by bacteria is depleted in heavy sulfur (S 34 ), and sulfate is enriched. The fractionation factor, 1.0575, is the greatest yet observed.
E S, Deevey, N, Nakai, M, Stuiver
openaire   +2 more sources

Calculation of sulfur isotope fractionation in sulfides

Geochimica et Cosmochimica Acta, 2006
Abstract The increment method has been successfully applied to calculate thermodynamic isotope fractionation factors of oxygen in silicates, oxides, carbonates, and sulfates. In this paper, we modified the increment method to calculate thermodynamic isotope fractionation factors of sulfur in sulfides, based on chemical features of sulfur–metal bonds ...
Yongbing Li, Jianming Liu
openaire   +1 more source

Sulfur Isotope Fractionation in the Biogeochemical Sulfur Cycle of Marine Sediments

Isotopes in Environmental and Health Studies, 2001
Abstract The sulfur isotopic record of sedimentary sulfides (mainly pyrite) and sulfates shows considerable variations in time and plays an important role in the biological and geochemical interpretation, e.g., of the evolution of life and the oxygen partial pressure of Earth's atmosphere (e.g. [1]).
openaire   +3 more sources

Anomalous fractionation of sulfur isotopes during sputtering

Rapid Communications in Mass Spectrometry, 2002
Abstract Secondary ion mass spectrometric (SIMS) measurements of sulfur isotope ratios obtained during sputtering with a Cs + beam and detection of negative secondary ions show a strong dependence of isotope fractionation on secondary ion energy for ions with ∼2–10 eV excess
openaire   +2 more sources

Sulfur isotope fractionation in sulfide mineralization

Economic Geology, 1960
The isotopic compositions of sulfides and sulfates from various types of sulfide formations were determined. A description of the preparation of sulfurous minerals for mass-spectrometric analysis and of the massspectrometric procedure is given. The results agree in several respects with previous investigations.
Sven Gavelin, A. Parwel, R. Ryhage
openaire   +1 more source

Isotopic fractionation of sulfur during COS hydrolysis

2023
Carbonyl Sulfide (COS) is the most abundant sulfur-containing gas in the atmosphere, and it is used as a proxy for terrestrial gross primary productivity (GPP). There are uncertainties in the COS fluxes estimations that limit this approach. Oceans are the major source of COS to the atmosphere.
Yasmin Avidani, Chen Davidson, Alon Angert, Alon Amrani   +3 more
openaire   +1 more source

SULFUR ISOTOPE FRACTIONATION BY SALMONELLA SPECIES

Canadian Journal of Microbiology, 1967
A number of Salmonella species are capable of fractionating sulfur isotopes during sulfite reduction under aerobic and anaerobic conditions. The product H2S may be enriched in 32S by over 3% as compared to the initial sulfite 32S/34S composition.
H. R. Krouse, R. G. L. McCready, S. A. Husain, J. N. Campbell   +3 more
openaire   +1 more source

Large Sulfur Isotope Fractionation Does Not Require Disproportionation

Science, 2011
In the absence of oxygenation, microbial activity can explain the magnitude of sulfur-isotope traces in sediments.
Min Sub, Sim, Tanja, Bosak, Shuhei, Ono
openaire   +2 more sources