Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea
The origin of modern seafloor methane emissions in the Barents Sea is tightly connected to the glacio-tectonic and oceanographic transformations following the last ice age. Those regional events induced geological structure re-activation and destabilization of gas hydrate reservoirs over large areas...
Published in: | Frontiers in Earth Science |
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2022
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ftdoajarticles:oai:doaj.org/article:725509070f524d508219d52b4522ac1b 2023-05-15T15:38:27+02:00 Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea Claudio Argentino Amicia Lee Luca Fallati Diana Sahy Daniel Birgel Jörn Peckmann Stefan Bünz Giuliana Panieri 2022-10-01T00:00:00Z https://doi.org/10.3389/feart.2022.1029471 https://doaj.org/article/725509070f524d508219d52b4522ac1b EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/feart.2022.1029471/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2022.1029471 https://doaj.org/article/725509070f524d508219d52b4522ac1b Frontiers in Earth Science, Vol 10 (2022) Aom (anaerobic oxidation of methane) authigenic carbonate cold seep lipid biomarkers U/Th Leirdjupet fault complex Science Q article 2022 ftdoajarticles https://doi.org/10.3389/feart.2022.1029471 2022-12-30T19:41:36Z The origin of modern seafloor methane emissions in the Barents Sea is tightly connected to the glacio-tectonic and oceanographic transformations following the last ice age. Those regional events induced geological structure re-activation and destabilization of gas hydrate reservoirs over large areas of the European continental margins, sustaining widespread fluid plumbing systems. Despite the increasing number of new active seep discoveries, their accurate geochronology and paleo-dynamic is still poorly resolved, thus hindering precise identification of triggering factors and mechanisms controlling past and future seafloor emissions. Here, we report the distribution, petrographic (thin section, electron backscatter diffraction), isotopic (δ13C, δ18O) and lipid biomarker composition of methane-derived carbonates collected from Leirdjupet Fault Complex, SW Barents Sea, at 300 m depth during an ROV survey in 2021. Carbonates are located inside a 120 x 220 m elongated pockmark and form <10 m2 bodies protruding for about 2 m above the adjacent seafloor. Microstructural analyses of vein-filling cements showed the occurrence of three–five generations of isopachous aragonitic cement separated by dissolution surfaces indicative of intermittent oxidizing conditions. The integration of phase-specific isotopic analysis and U/Th dating showed δ13C values between −28.6‰ to −10.1‰ and δ18O between 4.6‰ and 5.3‰, enabling us to track carbonate mineral precipitation over the last ∼8 ka. Lipid biomarkers and their compound-specific δ13C analysis in the bulk carbonate revealed the presence of anaerobic methanotrophic archaea of the ANME-2 clade associated with sulfate-reducing bacteria of the Seep-SRB1 clade, as well as traces of petroleum. Our results indicate that methane and petroleum seepage in this area followed a similar evolution as in other southernmost Barents Sea sites controlled by the asynchronous deglaciation of the Barents Sea shelf, and that methane-derived carbonate precipitation is still an active process at ... Article in Journal/Newspaper Barents Sea Directory of Open Access Journals: DOAJ Articles Barents Sea Leirdjupet ENVELOPE(20.833,20.833,74.333,74.333) Frontiers in Earth Science 10 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Aom (anaerobic oxidation of methane) authigenic carbonate cold seep lipid biomarkers U/Th Leirdjupet fault complex Science Q |
spellingShingle |
Aom (anaerobic oxidation of methane) authigenic carbonate cold seep lipid biomarkers U/Th Leirdjupet fault complex Science Q Claudio Argentino Amicia Lee Luca Fallati Diana Sahy Daniel Birgel Jörn Peckmann Stefan Bünz Giuliana Panieri Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea |
topic_facet |
Aom (anaerobic oxidation of methane) authigenic carbonate cold seep lipid biomarkers U/Th Leirdjupet fault complex Science Q |
description |
The origin of modern seafloor methane emissions in the Barents Sea is tightly connected to the glacio-tectonic and oceanographic transformations following the last ice age. Those regional events induced geological structure re-activation and destabilization of gas hydrate reservoirs over large areas of the European continental margins, sustaining widespread fluid plumbing systems. Despite the increasing number of new active seep discoveries, their accurate geochronology and paleo-dynamic is still poorly resolved, thus hindering precise identification of triggering factors and mechanisms controlling past and future seafloor emissions. Here, we report the distribution, petrographic (thin section, electron backscatter diffraction), isotopic (δ13C, δ18O) and lipid biomarker composition of methane-derived carbonates collected from Leirdjupet Fault Complex, SW Barents Sea, at 300 m depth during an ROV survey in 2021. Carbonates are located inside a 120 x 220 m elongated pockmark and form <10 m2 bodies protruding for about 2 m above the adjacent seafloor. Microstructural analyses of vein-filling cements showed the occurrence of three–five generations of isopachous aragonitic cement separated by dissolution surfaces indicative of intermittent oxidizing conditions. The integration of phase-specific isotopic analysis and U/Th dating showed δ13C values between −28.6‰ to −10.1‰ and δ18O between 4.6‰ and 5.3‰, enabling us to track carbonate mineral precipitation over the last ∼8 ka. Lipid biomarkers and their compound-specific δ13C analysis in the bulk carbonate revealed the presence of anaerobic methanotrophic archaea of the ANME-2 clade associated with sulfate-reducing bacteria of the Seep-SRB1 clade, as well as traces of petroleum. Our results indicate that methane and petroleum seepage in this area followed a similar evolution as in other southernmost Barents Sea sites controlled by the asynchronous deglaciation of the Barents Sea shelf, and that methane-derived carbonate precipitation is still an active process at ... |
format |
Article in Journal/Newspaper |
author |
Claudio Argentino Amicia Lee Luca Fallati Diana Sahy Daniel Birgel Jörn Peckmann Stefan Bünz Giuliana Panieri |
author_facet |
Claudio Argentino Amicia Lee Luca Fallati Diana Sahy Daniel Birgel Jörn Peckmann Stefan Bünz Giuliana Panieri |
author_sort |
Claudio Argentino |
title |
Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea |
title_short |
Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea |
title_full |
Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea |
title_fullStr |
Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea |
title_full_unstemmed |
Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea |
title_sort |
biogeochemistry and timing of methane-derived carbonate formation at leirdjupet fault complex, sw barents sea |
publisher |
Frontiers Media S.A. |
publishDate |
2022 |
url |
https://doi.org/10.3389/feart.2022.1029471 https://doaj.org/article/725509070f524d508219d52b4522ac1b |
long_lat |
ENVELOPE(20.833,20.833,74.333,74.333) |
geographic |
Barents Sea Leirdjupet |
geographic_facet |
Barents Sea Leirdjupet |
genre |
Barents Sea |
genre_facet |
Barents Sea |
op_source |
Frontiers in Earth Science, Vol 10 (2022) |
op_relation |
https://www.frontiersin.org/articles/10.3389/feart.2022.1029471/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2022.1029471 https://doaj.org/article/725509070f524d508219d52b4522ac1b |
op_doi |
https://doi.org/10.3389/feart.2022.1029471 |
container_title |
Frontiers in Earth Science |
container_volume |
10 |
_version_ |
1766369388507693056 |