Vlaams Instituut voor de Zee

platform voor marien onderzoek

In:

Open Marien Archief

Het Open Marien Archief van België (OMA) biedt vrije toegang tot de digitale publicaties over de Vlaamse kust en het Belgisch deel van de Noordzee, en alle andere mariene, estuariene en kustgebonden publicaties van Belgische auteurs en wetenschappers en van buitenlandse wetenschappers geaffilieerd aan een Belgische instelling.

Meer info

Nieuwe zoekopdracht
meld een fout in dit recordmandje (0): toevoegen | toon Print-vriendelijke versie

Sulfur and iron speciation in surface sediments along the northwestern margin of the Black Sea
Wijsman, J.W.M.; Middelburg, J.J.; Herman, P.M.J.; Böttcher, M.E.; Heip, C.H.R. (2001). Sulfur and iron speciation in surface sediments along the northwestern margin of the Black Sea. Mar. Chem. 74(4): 261-278
In: Marine Chemistry. Elsevier: Amsterdam. ISSN 0304-4203, meer
Peer reviewed article

Ook gepubliceerd als
  • Wijsman, J.W.M.; Middelburg, J.J.; Herman, P.M.J.; Böttcher, M.E.; Heip, C.H.R. (2001). Sulfur and iron speciation in surface sediments along the northwestern margin of the Black Sea, in: (2001). VLIZ Coll. Rep. 31(2001). VLIZ Collected Reprints: Marine and Coastal Research in Flanders, 31: pp. chapter 63, meer
  • Wijsman, J.W.M.; Middelburg, J.J.; Herman, P.M.J.; Böttcher, M.E.; Heip, C.H.R. (2001). Sulfur and iron speciation in surface sediments along the northwestern margin of the Black Sea. Freshwat. Biol. 55(4): 67-85, meer

Beschikbaar in Auteurs 

Trefwoorden
    Biogeochemische cyclus; Chemische speciatie; Ijzer; Micro-organismen; Oceaanbodem; Opgeloste zuurstof; Pyrite; Sedimentatie; Zwavel; MED, Zwarte Zee [gazetteer]; Marien

Auteurs  Top 
  • Wijsman, J.W.M., meer
  • Middelburg, J.J., meer
  • Herman, P.M.J., meer
  • Böttcher, M.E.
  • Heip, C.H.R., meer

Abstract
    The speciation of sedimentary sulfur (pyrite, acid volatile sulfides (AVS), SO, H2S, and sulfate) was analyzed in surface sediments recovered at different water depths from the northwestern margin of the Black Sea. Additionally, dissolved and dithionite-extractable iron were quantified, and the sulfur isotope ratios in pyrite were measured. Sulfur and iron cycling in surface sediments of the northwestern part of the Black Sea is largely influenced by (1) organic matter supply to the sediment, (2) availability of reactive iron compounds and (3) oxygen concentrations in the bottom waters. Biologically active, accumulating sediments just in front of the river deltas were characterized by high AVS contents and a fast depletion of sulfate concentration with depth, most likely due to high sulfate reduction rates (SRR). The δ34S values of pyrite in these sediments were relatively heavy (-8‰ to -21‰ vs. V-CDT). On the central shelf, where benthic mineralization rates are lower, re-oxidation processes may become more important and result in pyrite extremely depleted in δ34S (- 39‰ to -46‰ vs. V-CDT). A high variability in δ34S values of pyrite in sediments from the shelf-edge (-6‰ to -46‰ vs. V-CDT) reflects characteristic fluctuations in the oxygen concentrations of bottom waters or varying sediment accumulation rates. During periods of oxic conditions or low sediment accumulation rates, re-oxidation processes became important resulting in low AVS concentrations.and light δ34S values. Anoxic conditions in the bottom waters overlying shelf-edge sediments or periods of high accumulation rates are reflected in enhanced AVS contents and heavier sulfur isotope values.
    The sulfur and iron contents and the light and uniform pyrite ,isotopic composition (- 37‰ to - 39‰ vs. V-CDT) of sediments in the permanently anoxic deep sea (1494 m water depth) reflect the formation of pyrite in the upper part of the sulfidic water column and the anoxic surface sediment. The present study demonstrates that pyrite, which is extremely depleted in 34S can be found in the Black Sea surface sediments that are positioned both above and below the chemocline, despite differences in biogeochemical and miCrobial controlling factors.

 Top | Auteurs