Academic Journal
Anaerobic oxidation of methane alters sediment records of sulfur, iron and phosphorus in the Black Sea
| العنوان: | Anaerobic oxidation of methane alters sediment records of sulfur, iron and phosphorus in the Black Sea |
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| المؤلفون: | Egger, Matthias, Kraal, Peter, Jilbert, Tom, Sulu-Gambari, Fatimah, Sapart, Celia J., Röckmann, Thomas, Slomp, Caroline P. |
| المساهمون: | Environmental Sciences, Aquatic Biogeochemistry Research Unit (ABRU), Marine Ecosystems Research Group |
| بيانات النشر: | COPERNICUS GESELLSCHAFT MBH |
| سنة النشر: | 2017 |
| المجموعة: | Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto |
| مصطلحات موضوعية: | AUTHIGENIC APATITE FORMATION, EARLY DIAGENETIC PROCESSES, COASTAL MARINE-SEDIMENTS, SULFATE REDUCTION, ORGANIC-MATTER, BALTIC SEA, REACTIVE TRANSPORT, PADDY SOIL, FE(III) REDUCTION, IRON(III) OXIDES, Geosciences |
| الوصف: | The surface sediments in the Black Sea are underlain by extensive deposits of iron (Fe)-oxide-rich lake sediments that were deposited prior to the inflow of marine Mediterranean Sea waters ca. 9000 years ago. The subsequent downward diffusion of marine sulfate into the methane-bearing lake sediments has led to a multitude of diagenetic reactions in the sulfate-methane transition zone (SMTZ), including anaerobic oxidation of methane (AOM) with sulfate. While the sedimentary cycles of sulfur (S), methane and Fe in the SMTZ have been extensively studied, relatively little is known about the diagenetic alterations of the sediment record occurring below the SMTZ. Here we combine detailed geochemical analyses of the sediment and porewater with multicomponent diagenetic modeling to study the diagenetic alterations below the SMTZ at two sites in the western Black Sea. We focus on the dynamics of Fe, S and phosphorus (P), and demonstrate that diagenesis has strongly overprinted the sedimentary burial records of these elements. In line with previous studies in the Black Sea, we show that sulfate-mediated AOM substantially enhances the downward diffusive flux of sulfide into the deep limnic deposits. During this downward sulfidization, Fe oxides, Fe carbonates and Fe phosphates (e.g., vivianite) are converted to sulfide phases, leading to an enrichment in solid-phase S and the release of phosphate to the porewater. Below the sulfidization front, high concentrations of dissolved ferrous Fe (Fe2+) lead to sequestration of downward-diffusing phosphate as authigenic vivianite, resulting in a transient accumulation of total P directly below the sulfidization front. Our model results further demonstrate that downward-migrating sulfide becomes partly re-oxidized to sulfate due to reactions with oxidized Fe minerals, fueling a cryptic S cycle and thus stimulating slow rates of sulfate-driven AOM (similar to 1-100 pmol cm(-3) d(-1)) in the sulfate-depleted limnic deposits. However, this process is unlikely to explain the observed ... |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | application/pdf |
| اللغة: | English |
| ردمك: | 978-0-00-383966-1 0-00-383966-4 |
| Relation: | We thank the captain, crew and shipboard party of the PHOXY cruise aboard R/V Pelagia to the Black Sea in June 2013 and G. J. Reichart. We also thank NIOZ Marine Research Facilities for their support and K. Bakker and S. Ossebaar for their contribution to the porewater analysis. D. van de Meent, T. Claessen, T. Zalm, A. van Dijk, E. Dekker and G. Megens are acknowledged for technical and analytical assistance in Utrecht and M. Hagens for her support with the modeling. We further thank C. van der Veen for the methane isotope analysis. This research was funded by ERC Starting Grant 278364, NWO Open Competition Grant 822.01013 and NWO-Vici Grant 865.13.005 (to Caroline P. Slomp). In addition, Peter Kraal would like to acknowledge NWO Veni grant 863.14.014. This work was carried out under the program of the Netherlands Earth System Science Centre (NESSC), financially supported by the Ministry of Education, Culture and Science (OCW). Orit Sivan, Wei-Li Hong and an anonymous reviewer are gratefully acknowledged for their insightful comments and suggestions that improved the quality of the manuscript.; Egger , M , Kraal , P , Jilbert , T , Sulu-Gambari , F , Sapart , C J , Röckmann , T & Slomp , C P 2016 , ' Anaerobic oxidation of methane alters sediment records of sulfur, iron and phosphorus in the Black Sea ' , Biogeosciences , vol. 13 , no. 18 , pp. 5333-5355 . https://doi.org/10.5194/bg-13-5333-2016; ORCID: /0000-0001-8165-0168/work/29830305; http://hdl.handle.net/10138/175413; 4b0a4275-fdb4-407c-a952-ef5c985a41d5; 84989208451; 000383966400002 |
| الاتاحة: | http://hdl.handle.net/10138/175413 |
| Rights: | cc_by ; info:eu-repo/semantics/openAccess ; openAccess |
| رقم الانضمام: | edsbas.A3519A0D |
| قاعدة البيانات: | BASE |
| ردمك: | 9780003839661 0003839664 |
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