Sulfate reduction and methane oxidation activity below the sulfate-methane transition zone in Alaskan-Beaufort continental margin sediments: Implications for deep sulfur cycling

Simple item page
dc.contributor.authorTreude, Tina
dc.contributor.authorKrause, Stefan
dc.contributor.authorSchweers, Johanna
dc.contributor.authorDale, Andrew W.
dc.contributor.authorCoffin, Richard B.
dc.date.accessioned2021-11-12T18:04:26Z
dc.date.available2021-11-12T18:04:26Z
dc.date.issued2014-09-01
dc.description.abstractTwo ~6 m long sediment cores were collected along the ~300 m isobath on the Alaskan-Beaufort continental margin. Both cores showed distinct sulfate-methane transition zones (SMTZ) at 105 and 120 cm below seafloor (cmbsf). Sulfate was not completely depleted below the SMTZ but remained between 30 and 500 µM. Sulfate reduction and anaerobic oxidation of methane (AOM) determined by radiotracer incubations were active throughout the methanogenic zone. Although a mass balance could not explain the source of sulfate below the SMTZ, geochemical profiles and correlation network analyses of biotic and abiotic data suggest a cryptic sulfur cycle involving iron, manganese and barite. Inhibition experiments with molybdate and 2-bromoethanesulfonate (BES) indicated decoupling of sulfate reduction and AOM and competition between sulfate reducers and methanogens for substrates. While correlation network analyses predicted coupling of AOM to iron reduction, the addition of manganese or iron did not stimulate AOM. Since none of the classical archaeal anaerobic methanotrophs (ANME) were abundant, the involvement of unknown or unconventional phylotypes in AOM is conceivable. The resistance of AOM activity to inhibitors implies deviation from conventional enzymatic pathways. This work suggests the classical redox cascade of electron acceptor utilization based on Gibbs energy yields does not always hold in diffusion-dominated systems, and instead biotic processes may be more strongly coupled to mineralogy.en_US
dc.identifier.citationTreude, T., Krause, S., Maltby, J., Dale, A.W., Coffin, R. and Hamdan, L.J., 2014. Sulfate reduction and methane oxidation activity below the sulfate-methane transition zone in Alaskan Beaufort Sea continental margin sediments: Implications for deep sulfur cycling. Geochimica et Cosmochimica Acta, 144, pp.217-237. DOI:https://doi.org/10.1016/j.gca.2014.08.018en_US
dc.identifier.doihttps://doi.org/10.1016/j.gca.2014.08.018
dc.identifier.urihttps://hdl.handle.net/1969.6/90021
dc.language.isoen_USen_US
dc.publisherElsevieren_US
dc.subjectaomen_US
dc.subjectmethanogenesisen_US
dc.subjectironen_US
dc.subjectmanganeseen_US
dc.subjectbariteen_US
dc.subjectinhibitionen_US
dc.subjecttemperatureen_US
dc.titleSulfate reduction and methane oxidation activity below the sulfate-methane transition zone in Alaskan-Beaufort continental margin sediments: Implications for deep sulfur cyclingen_US
dc.typeArticleen_US

Files

Original bundle

Now showing 1 - 1 of 1
Thumbnail Image
Name:
Coffin_Richard_SulfurCycling.pdf
Size:
1.9 MB
Format:
Adobe Portable Document Format
Description:
Article
Download

License bundle

Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.72 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

COS Faculty Works