Sulphur and iron species in Dvurechenskii mud volcano sediments, supplement to: Lichtschlag, Anna; Kamyshny, Alexey; Ferdelman, Timothy G; de Beer, Dirk (2013): Intermediate sulfur oxidation state compounds in the euxinic surface sediments of the Dvurechenskii mud volcano (Black Sea). Geochimica et Cosmochimica Acta, 105, 130-145

DOI

The deep Black Sea is known to be depleted in electron-acceptors for sulphide oxidation. This study on depth distributions of sulphur species (S(II), S(0),S(n)2-,S2O32-,SO32-,SO42-) in the Dvurechenskii mud volcano, a cold seep situated in the permanently anoxic eastern Black Sea basin (Sorokin Trough, 2060 m water depth), showed remarkable concentrations of sulphide oxidation products. Sulphite concentrations of up to 11 µmol L1-, thiosulphate concentrations of up to 22 µmol L1-, zero-valent sulphur concentrations of up to 150 µmol L1- and up to five polysulphide species were measured in the upper 20 cm of the sediment. Electron-acceptors found to be available in the Dvurechenskii mud volcano (DMV) for the oxidation of hydrogen sulphide to sulphide oxidation intermediates are iron-minerals, and probably also reactive manganese phases. Up to 60 µmol g1- of reactive iron-minerals and up to 170 µmol L**1- dissolved iron was present in the central summit with the highest fluid upflow and fresh mud outflow. Thus, the source for the oxidative power in the DMV are reactive iron phases extruded with the mud from an ancient source in the deeply buried sediments, leading to the formation of various sulphur intermediates in comparably high concentrations. Another possible source of sulphide oxidation intermediates in DMV sediments could be the formation of zero-valent sulphur by sulphate dependent anaerobic microbial oxidation of methane followed by disproportionation of zero-valent sulphur. Sulphide oxidation intermediates, which are produced by these processes, do not reach thermodynamic equilibrium with rhombic sulphur, especially close to the active center of the DMV due to a short equilibration time. Thus, mud volcano sediments, such as in the DMV, can provide oxidizing niches even in a highly reduced environment like the abyssal part of the Black Sea.

Identifier
DOI http://dx.doi.org/doi:10.1594/PANGAEA.810517
Metadata Access http://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite3&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.810517
Provenance
Creator Lichtschlag, Anna;Kamyshny, Alexey
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2013
Rights Creative Commons Attribution 3.0 Unported (CC-BY)
Representation
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Discipline Earth System Research
Spatial Coverage (44N-44N,35E-35E)
Temporal Point 2007-02-26T11:59:59Z