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Bo Barker Jørgensen

The sulfur cycle below the sulfate-methane transition of marine sediments

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The sulfur cycle below the sulfate-methane transition of marine sediments. / Pellerin, Andre; Antler, Gilad; Roy, Hans; Findlay, Alyssa; Beulig, Felix; Scholze, Caroline; Turchyn, Alexandra V.; Jorgensen, Bo Barker.

In: Geochimica et Cosmochimica Acta, Vol. 239, 15.10.2018, p. 74-89.

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

Harvard

Pellerin, A, Antler, G, Roy, H, Findlay, A, Beulig, F, Scholze, C, Turchyn, AV & Jorgensen, BB 2018, 'The sulfur cycle below the sulfate-methane transition of marine sediments', Geochimica et Cosmochimica Acta, vol. 239, pp. 74-89. https://doi.org/10.1016/j.gca.2018.07.027

APA

Pellerin, A., Antler, G., Roy, H., Findlay, A., Beulig, F., Scholze, C., Turchyn, A. V., & Jorgensen, B. B. (2018). The sulfur cycle below the sulfate-methane transition of marine sediments. Geochimica et Cosmochimica Acta, 239, 74-89. https://doi.org/10.1016/j.gca.2018.07.027

CBE

Pellerin A, Antler G, Roy H, Findlay A, Beulig F, Scholze C, Turchyn AV, Jorgensen BB. 2018. The sulfur cycle below the sulfate-methane transition of marine sediments. Geochimica et Cosmochimica Acta. 239:74-89. https://doi.org/10.1016/j.gca.2018.07.027

MLA

Vancouver

Pellerin A, Antler G, Roy H, Findlay A, Beulig F, Scholze C et al. The sulfur cycle below the sulfate-methane transition of marine sediments. Geochimica et Cosmochimica Acta. 2018 Oct 15;239:74-89. https://doi.org/10.1016/j.gca.2018.07.027

Author

Pellerin, Andre ; Antler, Gilad ; Roy, Hans ; Findlay, Alyssa ; Beulig, Felix ; Scholze, Caroline ; Turchyn, Alexandra V. ; Jorgensen, Bo Barker. / The sulfur cycle below the sulfate-methane transition of marine sediments. In: Geochimica et Cosmochimica Acta. 2018 ; Vol. 239. pp. 74-89.

Bibtex

@article{ef5c9ffa5b8e44cbaa5bc7ade16bb939,
title = "The sulfur cycle below the sulfate-methane transition of marine sediments",
abstract = "The study of sulfate reduction below the sulfate-methane transition (SMT) in marine sediments requires strict precautions to avoid sulfate contamination from seawater sulfate or from sulfide oxidation during handling. We experimented with different methods of sampling porewater sulfate and found that modifications to our sampling procedure reduced the measured sulfate concentrations from hundreds of micromolar to ten micromolar or less. We here recommend some key modifications to porewater sampling to avoid contamination or oxidation artifacts, for example when measuring very low sulfate concentrations below the SMT of marine sediments. At three sites in Aarhus Bay, the sulfate concentrations below the SMT remained around ten micromolar. The calculated free energy change, ΔG r, available for sulfate reduction by such low concentrations is between −17.9 and −11.9 kJ mol −1 sulfate. This is near or below the energy yields that have previously been calculated for microbial sulfate reduction in marine sediments. The three sites are characterized by measurable and very different sulfate reduction rates depending on the depth and sediment age of the SMT. Our data show that sulfate is being consumed below the SMT in spite of the low sulfate concentrations. As sulfate is not drawn down to even lower concentrations, it must be continually regenerated below the SMT, most likely by Fe(III)-driven sulfide oxidation concurrent with the sulfate reduction. We conclude that the low sub-SMT sulfate concentrations are in steady state between reduction and production and are thermodynamically controlled by the minimum ΔG r requirements by sulfate reducing bacteria while sulfate reduction rates are controlled by the rate of sulfide oxidation. This study deals with the general sampling of uncontaminated pore water and hints to a systemic problem with low levels of contamination in porewater induced by coring and pore water extraction. Below the SMT, this contamination could be detected but above the SMT it goes unnoticed. Low levels of contamination as observed in this study may affect other low concentration or redox-sensitive elements in pore water. ",
keywords = "VOLATILE FATTY-ACIDS, SANTA-BARBARA BASIN, AARHUS BAY, ISOTOPE FRACTIONATION, REDUCING BACTERIA, ANAEROBIC OXIDATION, SULFIDE OXIDATION, REDUCTION RATES, BLACK-SEA, DENMARK",
author = "Andre Pellerin and Gilad Antler and Hans Roy and Alyssa Findlay and Felix Beulig and Caroline Scholze and Turchyn, {Alexandra V.} and Jorgensen, {Bo Barker}",
year = "2018",
month = oct,
day = "15",
doi = "10.1016/j.gca.2018.07.027",
language = "English",
volume = "239",
pages = "74--89",
journal = "Geochimica et Cosmochimica Acta",
issn = "0016-7037",
publisher = "Pergamon Press",

}

RIS

TY - JOUR

T1 - The sulfur cycle below the sulfate-methane transition of marine sediments

AU - Pellerin, Andre

AU - Antler, Gilad

AU - Roy, Hans

AU - Findlay, Alyssa

AU - Beulig, Felix

AU - Scholze, Caroline

AU - Turchyn, Alexandra V.

AU - Jorgensen, Bo Barker

PY - 2018/10/15

Y1 - 2018/10/15

N2 - The study of sulfate reduction below the sulfate-methane transition (SMT) in marine sediments requires strict precautions to avoid sulfate contamination from seawater sulfate or from sulfide oxidation during handling. We experimented with different methods of sampling porewater sulfate and found that modifications to our sampling procedure reduced the measured sulfate concentrations from hundreds of micromolar to ten micromolar or less. We here recommend some key modifications to porewater sampling to avoid contamination or oxidation artifacts, for example when measuring very low sulfate concentrations below the SMT of marine sediments. At three sites in Aarhus Bay, the sulfate concentrations below the SMT remained around ten micromolar. The calculated free energy change, ΔG r, available for sulfate reduction by such low concentrations is between −17.9 and −11.9 kJ mol −1 sulfate. This is near or below the energy yields that have previously been calculated for microbial sulfate reduction in marine sediments. The three sites are characterized by measurable and very different sulfate reduction rates depending on the depth and sediment age of the SMT. Our data show that sulfate is being consumed below the SMT in spite of the low sulfate concentrations. As sulfate is not drawn down to even lower concentrations, it must be continually regenerated below the SMT, most likely by Fe(III)-driven sulfide oxidation concurrent with the sulfate reduction. We conclude that the low sub-SMT sulfate concentrations are in steady state between reduction and production and are thermodynamically controlled by the minimum ΔG r requirements by sulfate reducing bacteria while sulfate reduction rates are controlled by the rate of sulfide oxidation. This study deals with the general sampling of uncontaminated pore water and hints to a systemic problem with low levels of contamination in porewater induced by coring and pore water extraction. Below the SMT, this contamination could be detected but above the SMT it goes unnoticed. Low levels of contamination as observed in this study may affect other low concentration or redox-sensitive elements in pore water.

AB - The study of sulfate reduction below the sulfate-methane transition (SMT) in marine sediments requires strict precautions to avoid sulfate contamination from seawater sulfate or from sulfide oxidation during handling. We experimented with different methods of sampling porewater sulfate and found that modifications to our sampling procedure reduced the measured sulfate concentrations from hundreds of micromolar to ten micromolar or less. We here recommend some key modifications to porewater sampling to avoid contamination or oxidation artifacts, for example when measuring very low sulfate concentrations below the SMT of marine sediments. At three sites in Aarhus Bay, the sulfate concentrations below the SMT remained around ten micromolar. The calculated free energy change, ΔG r, available for sulfate reduction by such low concentrations is between −17.9 and −11.9 kJ mol −1 sulfate. This is near or below the energy yields that have previously been calculated for microbial sulfate reduction in marine sediments. The three sites are characterized by measurable and very different sulfate reduction rates depending on the depth and sediment age of the SMT. Our data show that sulfate is being consumed below the SMT in spite of the low sulfate concentrations. As sulfate is not drawn down to even lower concentrations, it must be continually regenerated below the SMT, most likely by Fe(III)-driven sulfide oxidation concurrent with the sulfate reduction. We conclude that the low sub-SMT sulfate concentrations are in steady state between reduction and production and are thermodynamically controlled by the minimum ΔG r requirements by sulfate reducing bacteria while sulfate reduction rates are controlled by the rate of sulfide oxidation. This study deals with the general sampling of uncontaminated pore water and hints to a systemic problem with low levels of contamination in porewater induced by coring and pore water extraction. Below the SMT, this contamination could be detected but above the SMT it goes unnoticed. Low levels of contamination as observed in this study may affect other low concentration or redox-sensitive elements in pore water.

KW - VOLATILE FATTY-ACIDS

KW - SANTA-BARBARA BASIN

KW - AARHUS BAY

KW - ISOTOPE FRACTIONATION

KW - REDUCING BACTERIA

KW - ANAEROBIC OXIDATION

KW - SULFIDE OXIDATION

KW - REDUCTION RATES

KW - BLACK-SEA

KW - DENMARK

U2 - 10.1016/j.gca.2018.07.027

DO - 10.1016/j.gca.2018.07.027

M3 - Journal article

VL - 239

SP - 74

EP - 89

JO - Geochimica et Cosmochimica Acta

JF - Geochimica et Cosmochimica Acta

SN - 0016-7037

ER -