Microbially mediated kinetic sulfur isotope fractionation: reactive transport modeling benchmark
نویسندگان
چکیده
منابع مشابه
Questions regarding Precambrian sulfur isotope fractionation.
The discovery by Farquhar et al. (1) of mass-independent isotope fractionation of S and S in rocks formed more than ;2 billion years ago (Ga), but not in younger rocks, has boosted the theory postulating a dramatic change from an anoxic to an oxygen-rich atmosphere about 2 Ga. That is because the only known natural process that may cause mass-independent fractionation of both S and S involves a...
متن کاملMass-independent sulfur isotope fractionation during photochemistry of sulfur dioxide
Mass-independent sulfur isotope signatures are observed in Archean and early Paleoproterozoic sedimentary sulfate and sulfide minerals, and provide the most robust constraints on early atmospheric oxygen levels. Smaller mass-independent sulfur isotope anomalies are observed in ice cores and interpreted as a tracer of stratospheric volcanic loading. Photochemistry of sulfur dioxide (SO 2) has be...
متن کاملConsidering a Threshold Energy in Reactive Transport Modeling of Microbially Mediated Redox Reactions in an Arsenic-Affected Aquifer
The reductive dissolution of Fe-oxide driven by organic matter oxidation is the primary mechanism accepted for As mobilization in several alluvial aquifers. These processes are often mediated by microorganisms that require a minimum Gibbs energy available to conduct the reaction in order to sustain their life functions. Implementing this threshold energy in reactive transport modeling is rarely...
متن کاملMicroscale reservoir effects on microbial sulfur isotope fractionation
Microbial sulfate reduction can impart strong sulfur isotope fractionation by preferentially using the lighter 32SO2! 4 over the heavier 34SO 4 . The magnitude of fractionation depends on a number of factors, including ambient concentrations of sulfate and electron donors. Sulfur isotope compositions in sedimentary rocks thus facilitate reconstruction of past environmental conditions, such as s...
متن کاملPhysiology of Multiple Sulfur Isotope Fractionation during Microbial Sulfate Reduction
Microbial sulfate reduction (MSR) utilizes sulfate as an electron acceptor and produces sulfide that is depleted in heavy isotopes of sulfur relative to starting sulfate. The fractionation of S-isotopes is commonly used to trace the biogeochemical cycling of sulfur in nature, but a mechanistic understanding of factors that control the range of isotope fractionation is still lacking. This thesis...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Computational Geosciences
سال: 2020
ISSN: 1420-0597,1573-1499
DOI: 10.1007/s10596-020-09988-9