Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments
This study reports the very first results on high-resolution sampling of sediments and their porewaters from three thermokarst (thaw) lakes representing different stages of ecosystem development located within the Nadym-Pur interfluve of the Western Siberia plain. Up to present time, the lake sedime...
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2011
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ftdoajarticles:oai:doaj.org/article:7217ef9107ab4c899a0aca5151a818f3 2023-05-15T17:57:43+02:00 Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments S. Audry O. S. Pokrovsky L. S. Shirokova S. N. Kirpotin B. Dupré 2011-11-01T00:00:00Z https://doi.org/10.5194/bg-8-3341-2011 https://doaj.org/article/7217ef9107ab4c899a0aca5151a818f3 EN eng Copernicus Publications http://www.biogeosciences.net/8/3341/2011/bg-8-3341-2011.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-8-3341-2011 1726-4170 1726-4189 https://doaj.org/article/7217ef9107ab4c899a0aca5151a818f3 Biogeosciences, Vol 8, Iss 11, Pp 3341-3358 (2011) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2011 ftdoajarticles https://doi.org/10.5194/bg-8-3341-2011 2022-12-31T03:28:27Z This study reports the very first results on high-resolution sampling of sediments and their porewaters from three thermokarst (thaw) lakes representing different stages of ecosystem development located within the Nadym-Pur interfluve of the Western Siberia plain. Up to present time, the lake sediments of this and other permafrost-affected regions remain unexplored regarding their biogeochemical behavior. The aim of this study was to (i) document the early diagenesic processes in order to assess their impact on the organic carbon stored in the underlying permafrost, and (ii) characterize the post-depositional redistribution of trace elements and their impact on the water column. The estimated organic carbon (OC) stock in thermokarst lake sediments of 14 ± 2 kg m −2 is low compared to that reported for peat soils from the same region and denotes intense organic matter (OM) mineralization. Mineralization of OM in the thermokarst lake sediments proceeds under anoxic conditions in all the three lakes. In the course of the lake development, a shift in mineralization pathways from nitrate and sulfate to Fe- and Mn-oxyhydroxides as the main terminal electron acceptors in the early diagenetic reactions was suggested. This shift was likely promoted by the diagenetic consumption of nitrate and sulfate and their gradual depletion in the water column due to progressively decreasing frozen peat lixiviation occurring at the lake's borders. Trace elements were mobilized from host phases (OM and Fe- and Mn-oxyhydroxides) and partly sequestered in the sediment in the form of authigenic Fe-sulfides. Arsenic and Sb cycling was also closely linked to that of OM and Fe- and Mn-oxyhydroxides. Shallow diagenetic enrichment of particulate Sb was observed in the less mature stages. As a result of authigenic sulfide precipitation, the sediments of the early stage of ecosystem development were a sink for water column Cu, Zn, Cd, Pb and Sb. In contrast, at all stages of ecosystem development, the sediments were a source of dissolved Co, Ni ... Article in Journal/Newspaper permafrost Thermokarst Siberia Directory of Open Access Journals: DOAJ Articles Nadym ENVELOPE(72.517,72.517,65.533,65.533) Biogeosciences 8 11 3341 3358 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 S. Audry O. S. Pokrovsky L. S. Shirokova S. N. Kirpotin B. Dupré Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
This study reports the very first results on high-resolution sampling of sediments and their porewaters from three thermokarst (thaw) lakes representing different stages of ecosystem development located within the Nadym-Pur interfluve of the Western Siberia plain. Up to present time, the lake sediments of this and other permafrost-affected regions remain unexplored regarding their biogeochemical behavior. The aim of this study was to (i) document the early diagenesic processes in order to assess their impact on the organic carbon stored in the underlying permafrost, and (ii) characterize the post-depositional redistribution of trace elements and their impact on the water column. The estimated organic carbon (OC) stock in thermokarst lake sediments of 14 ± 2 kg m −2 is low compared to that reported for peat soils from the same region and denotes intense organic matter (OM) mineralization. Mineralization of OM in the thermokarst lake sediments proceeds under anoxic conditions in all the three lakes. In the course of the lake development, a shift in mineralization pathways from nitrate and sulfate to Fe- and Mn-oxyhydroxides as the main terminal electron acceptors in the early diagenetic reactions was suggested. This shift was likely promoted by the diagenetic consumption of nitrate and sulfate and their gradual depletion in the water column due to progressively decreasing frozen peat lixiviation occurring at the lake's borders. Trace elements were mobilized from host phases (OM and Fe- and Mn-oxyhydroxides) and partly sequestered in the sediment in the form of authigenic Fe-sulfides. Arsenic and Sb cycling was also closely linked to that of OM and Fe- and Mn-oxyhydroxides. Shallow diagenetic enrichment of particulate Sb was observed in the less mature stages. As a result of authigenic sulfide precipitation, the sediments of the early stage of ecosystem development were a sink for water column Cu, Zn, Cd, Pb and Sb. In contrast, at all stages of ecosystem development, the sediments were a source of dissolved Co, Ni ... |
format |
Article in Journal/Newspaper |
author |
S. Audry O. S. Pokrovsky L. S. Shirokova S. N. Kirpotin B. Dupré |
author_facet |
S. Audry O. S. Pokrovsky L. S. Shirokova S. N. Kirpotin B. Dupré |
author_sort |
S. Audry |
title |
Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments |
title_short |
Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments |
title_full |
Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments |
title_fullStr |
Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments |
title_full_unstemmed |
Organic matter mineralization and trace element post-depositional redistribution in Western Siberia thermokarst lake sediments |
title_sort |
organic matter mineralization and trace element post-depositional redistribution in western siberia thermokarst lake sediments |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
https://doi.org/10.5194/bg-8-3341-2011 https://doaj.org/article/7217ef9107ab4c899a0aca5151a818f3 |
long_lat |
ENVELOPE(72.517,72.517,65.533,65.533) |
geographic |
Nadym |
geographic_facet |
Nadym |
genre |
permafrost Thermokarst Siberia |
genre_facet |
permafrost Thermokarst Siberia |
op_source |
Biogeosciences, Vol 8, Iss 11, Pp 3341-3358 (2011) |
op_relation |
http://www.biogeosciences.net/8/3341/2011/bg-8-3341-2011.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-8-3341-2011 1726-4170 1726-4189 https://doaj.org/article/7217ef9107ab4c899a0aca5151a818f3 |
op_doi |
https://doi.org/10.5194/bg-8-3341-2011 |
container_title |
Biogeosciences |
container_volume |
8 |
container_issue |
11 |
container_start_page |
3341 |
op_container_end_page |
3358 |
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1766166206747770880 |