Molecular biomarkers in Batagay megaslump permafrost deposits reveal clear differences in organic matter preservation between glacial and interglacial periods
The Batagay megaslump, a permafrost thaw feature in north-eastern Siberia, provides access to ancient permafrost up to ∼650 kyr old. We aimed to assess the permafrost-locked organic matter (OM) quality and to deduce palaeo-environmental information on glacial–interglacial timescales. We sampled five...
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ftcopernicus:oai:publications.copernicus.org:tc100893 2023-05-15T16:36:44+02:00 Molecular biomarkers in Batagay megaslump permafrost deposits reveal clear differences in organic matter preservation between glacial and interglacial periods Jongejans, Loeka L. Mangelsdorf, Kai Karger, Cornelia Opel, Thomas Wetterich, Sebastian Courtin, Jérémy Meyer, Hanno Kizyakov, Alexander I. Grosse, Guido Shepelev, Andrei G. Syromyatnikov, Igor I. Fedorov, Alexander N. Strauss, Jens 2022-09-08 application/pdf https://doi.org/10.5194/tc-16-3601-2022 https://tc.copernicus.org/articles/16/3601/2022/ eng eng doi:10.5194/tc-16-3601-2022 https://tc.copernicus.org/articles/16/3601/2022/ eISSN: 1994-0424 Text 2022 ftcopernicus https://doi.org/10.5194/tc-16-3601-2022 2022-09-12T16:22:53Z The Batagay megaslump, a permafrost thaw feature in north-eastern Siberia, provides access to ancient permafrost up to ∼650 kyr old. We aimed to assess the permafrost-locked organic matter (OM) quality and to deduce palaeo-environmental information on glacial–interglacial timescales. We sampled five stratigraphic units exposed on the 55 m high slump headwall and analysed lipid biomarkers (alkanes, fatty acids and alcohols). Our findings revealed similar biogeochemical signatures for the glacial periods: the lower ice complex (Marine Isotope Stage (MIS) 16 or earlier), the lower sand unit (sometime between MIS 16–6) and the upper ice complex (MIS 4–2). The OM in these units has a terrestrial character, and microbial activity was likely limited. Contrarily, the n -alkane and fatty acid distributions differed for the units from interglacial periods: the woody layer (MIS 5), separating the lower sand unit and the upper ice complex, and the Holocene cover (MIS 1), on top of the upper ice complex. The woody layer, marking a permafrost degradation disconformity, contained markers of terrestrial origin (sterols) and high microbial decomposition ( iso - and anteiso -fatty acids). In the Holocene cover, biomarkers pointed to wet depositional conditions and we identified branched and cyclic alkanes, which are likely of microbial origin. Higher OM decomposition characterised the interglacial periods. As climate warming will continue permafrost degradation in the Batagay megaslump and in other areas, large amounts of deeply buried ancient OM with variable composition and degradability are mobilised, likely significantly enhancing greenhouse gas emissions from permafrost regions. Text Ice permafrost Siberia Copernicus Publications: E-Journals The Cryosphere 16 9 3601 3617 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
The Batagay megaslump, a permafrost thaw feature in north-eastern Siberia, provides access to ancient permafrost up to ∼650 kyr old. We aimed to assess the permafrost-locked organic matter (OM) quality and to deduce palaeo-environmental information on glacial–interglacial timescales. We sampled five stratigraphic units exposed on the 55 m high slump headwall and analysed lipid biomarkers (alkanes, fatty acids and alcohols). Our findings revealed similar biogeochemical signatures for the glacial periods: the lower ice complex (Marine Isotope Stage (MIS) 16 or earlier), the lower sand unit (sometime between MIS 16–6) and the upper ice complex (MIS 4–2). The OM in these units has a terrestrial character, and microbial activity was likely limited. Contrarily, the n -alkane and fatty acid distributions differed for the units from interglacial periods: the woody layer (MIS 5), separating the lower sand unit and the upper ice complex, and the Holocene cover (MIS 1), on top of the upper ice complex. The woody layer, marking a permafrost degradation disconformity, contained markers of terrestrial origin (sterols) and high microbial decomposition ( iso - and anteiso -fatty acids). In the Holocene cover, biomarkers pointed to wet depositional conditions and we identified branched and cyclic alkanes, which are likely of microbial origin. Higher OM decomposition characterised the interglacial periods. As climate warming will continue permafrost degradation in the Batagay megaslump and in other areas, large amounts of deeply buried ancient OM with variable composition and degradability are mobilised, likely significantly enhancing greenhouse gas emissions from permafrost regions. |
format |
Text |
author |
Jongejans, Loeka L. Mangelsdorf, Kai Karger, Cornelia Opel, Thomas Wetterich, Sebastian Courtin, Jérémy Meyer, Hanno Kizyakov, Alexander I. Grosse, Guido Shepelev, Andrei G. Syromyatnikov, Igor I. Fedorov, Alexander N. Strauss, Jens |
spellingShingle |
Jongejans, Loeka L. Mangelsdorf, Kai Karger, Cornelia Opel, Thomas Wetterich, Sebastian Courtin, Jérémy Meyer, Hanno Kizyakov, Alexander I. Grosse, Guido Shepelev, Andrei G. Syromyatnikov, Igor I. Fedorov, Alexander N. Strauss, Jens Molecular biomarkers in Batagay megaslump permafrost deposits reveal clear differences in organic matter preservation between glacial and interglacial periods |
author_facet |
Jongejans, Loeka L. Mangelsdorf, Kai Karger, Cornelia Opel, Thomas Wetterich, Sebastian Courtin, Jérémy Meyer, Hanno Kizyakov, Alexander I. Grosse, Guido Shepelev, Andrei G. Syromyatnikov, Igor I. Fedorov, Alexander N. Strauss, Jens |
author_sort |
Jongejans, Loeka L. |
title |
Molecular biomarkers in Batagay megaslump permafrost deposits reveal clear differences in organic matter preservation between glacial and interglacial periods |
title_short |
Molecular biomarkers in Batagay megaslump permafrost deposits reveal clear differences in organic matter preservation between glacial and interglacial periods |
title_full |
Molecular biomarkers in Batagay megaslump permafrost deposits reveal clear differences in organic matter preservation between glacial and interglacial periods |
title_fullStr |
Molecular biomarkers in Batagay megaslump permafrost deposits reveal clear differences in organic matter preservation between glacial and interglacial periods |
title_full_unstemmed |
Molecular biomarkers in Batagay megaslump permafrost deposits reveal clear differences in organic matter preservation between glacial and interglacial periods |
title_sort |
molecular biomarkers in batagay megaslump permafrost deposits reveal clear differences in organic matter preservation between glacial and interglacial periods |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-3601-2022 https://tc.copernicus.org/articles/16/3601/2022/ |
genre |
Ice permafrost Siberia |
genre_facet |
Ice permafrost Siberia |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-16-3601-2022 https://tc.copernicus.org/articles/16/3601/2022/ |
op_doi |
https://doi.org/10.5194/tc-16-3601-2022 |
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The Cryosphere |
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16 |
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9 |
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3601 |
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3617 |
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1766027059656654848 |