Results 231 to 240 of about 4,448 (271)

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

Seasonal Influence on Subsurface Rates of Microbial Sulfate Reduction and Sulfur Isotope Fractionation in Coastal Sediments

Global Biogeochemical Cycles
Sulfur isotope fractionation during microbial sulfate reduction is often preserved in the mineral pyrite (FeS 2 ), which has been used to reconstruct the biogeochemical sulfur cycle and redox geochemistry of the oceans over the Earth history ...
Bizhou Zhu, Harold J Bradbury, Thomas I Marquand   +2 more
exaly   +5 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

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

Fractionation of sulfur and oxygen isotopes in sulfate by soil sorption

Geochimica et Cosmochimica Acta, 1990
Both field and laboratory data indicate that there is no significant isotope fractionation of sulfate during sorption in upland forest Podzols. The dominant sulfate sorption process in these soils is adsorption onto mineral surfaces. In the Plastic Lake watershed, Dorset, Ontario, Canada, fractions of sulfate from Podzol B-horizons have the following ...
Van Stempvoort, D.R., Reardon, E.J., Fritz, P.J.   +2 more
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Sulfur isotope fractionation in the Pb-S system

Earth and Planetary Science Letters, 1970
Abstract Sulfur isotope fractionation among phases of the Pb-S system was investigated by silica tube experiments. Strong kinetic effects were observed when Pb reacts with S to form PbS. The difference in reaction rates of 32 S and 34 S gives lead sulfide enriched in the light S-isotope.
H. Puchelt, G. Kullerud
openaire   +1 more source

Fractionation of sulfur isotopes by the yeast Saccharomyces cerevisiae

Geochimica et Cosmochimica Acta, 1974
Growing and resting cell suspensions of Baker's yeast (Saccharomyces cerevisiae) were permitted to metabolize sulfite and sulfate under a variety of environmental conditions. Enrichment of S32 in the H2S released during reduction of sulfate under growing conditions was consistently lower (δS34 < −25%.) than enrichment during reduction of sulfite under ...
R.G.L. McCready, I.R. Kaplan, G.A. Din
openaire   +1 more source