Magnetotactic bacterial abundance in pelagic marine environments is limited by organic carbon flux and availability of dissolved iron
Magnetotactic bacteria intracellularly biomineralize magnetite of an ideal grain size for recording palaeomagnetic signals. However, bacterial magnetite has only been reported in a few pre-Quaternary records because progressive burial into anoxic diagenetic environments causes its dissolution. Deep-...
Published in: | Earth and Planetary Science Letters |
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Online Access: | http://hdl.handle.net/11381/2368099 https://doi.org/10.1016/j.epsl.2011.08.011 |
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ftunivparmairis:oai:air.unipr.it:11381/2368099 2024-04-21T08:12:15+00:00 Magnetotactic bacterial abundance in pelagic marine environments is limited by organic carbon flux and availability of dissolved iron A. P. Roberts F. Florindo G. Villa L. Chang L. Jovane S. Bohaty J. C. Larrasoaña D. Heslop J. Fitz Gerald Roberts, A. P. Florindo, F. Villa, G. Chang, L. Jovane, L. Bohaty, S. Larrasoaña, J. C. Heslop, D. Fitz Gerald, J. 2011 http://hdl.handle.net/11381/2368099 https://doi.org/10.1016/j.epsl.2011.08.011 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000298273500029 volume:310 firstpage:441 lastpage:452 numberofpages:12 journal:EARTH AND PLANETARY SCIENCE LETTERS http://hdl.handle.net/11381/2368099 doi:10.1016/j.epsl.2011.08.011 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-80053381935 info:eu-repo/semantics/closedAccess info:eu-repo/semantics/article 2011 ftunivparmairis https://doi.org/10.1016/j.epsl.2011.08.011 2024-03-28T01:17:50Z Magnetotactic bacteria intracellularly biomineralize magnetite of an ideal grain size for recording palaeomagnetic signals. However, bacterial magnetite has only been reported in a few pre-Quaternary records because progressive burial into anoxic diagenetic environments causes its dissolution. Deep-sea carbonate sequences provide optimal environments for preserving bacterial magnetite due to low rates of organic carbon burial and expanded pore-water redox zonations. Such sequences often do not become anoxic for tens to hundreds of metres below the seafloor. Nevertheless, the biogeochemical factors that control magnetotactic bacterial populations in such settings are not well known. We document the preservation of bacterial magnetite, which dominates the palaeomagnetic signal throughout Eocene pelagic carbonates from the southern Kerguelen Plateau, Southern Ocean. We provide evidence that iron fertilization, associated with increased aeolian dust flux, resulted in surface water eutrophication in the late Eocene that controlled bacterial magnetite abundance via export of organic carbon to the seafloor. Increased flux of aeolian ironbearing phases also delivered iron to the seafloor, some of which became bioavailable through iron reduction. Our results suggest that magnetotactic bacterial populations in pelagic settings depend crucially on particulate iron and organic carbon delivery to the seafloor. Article in Journal/Newspaper Southern Ocean Archivio della ricerca dell'Università di Parma (CINECA IRIS) Earth and Planetary Science Letters 310 3-4 441 452 |
institution |
Open Polar |
collection |
Archivio della ricerca dell'Università di Parma (CINECA IRIS) |
op_collection_id |
ftunivparmairis |
language |
English |
description |
Magnetotactic bacteria intracellularly biomineralize magnetite of an ideal grain size for recording palaeomagnetic signals. However, bacterial magnetite has only been reported in a few pre-Quaternary records because progressive burial into anoxic diagenetic environments causes its dissolution. Deep-sea carbonate sequences provide optimal environments for preserving bacterial magnetite due to low rates of organic carbon burial and expanded pore-water redox zonations. Such sequences often do not become anoxic for tens to hundreds of metres below the seafloor. Nevertheless, the biogeochemical factors that control magnetotactic bacterial populations in such settings are not well known. We document the preservation of bacterial magnetite, which dominates the palaeomagnetic signal throughout Eocene pelagic carbonates from the southern Kerguelen Plateau, Southern Ocean. We provide evidence that iron fertilization, associated with increased aeolian dust flux, resulted in surface water eutrophication in the late Eocene that controlled bacterial magnetite abundance via export of organic carbon to the seafloor. Increased flux of aeolian ironbearing phases also delivered iron to the seafloor, some of which became bioavailable through iron reduction. Our results suggest that magnetotactic bacterial populations in pelagic settings depend crucially on particulate iron and organic carbon delivery to the seafloor. |
author2 |
Roberts, A. P. Florindo, F. Villa, G. Chang, L. Jovane, L. Bohaty, S. Larrasoaña, J. C. Heslop, D. Fitz Gerald, J. |
format |
Article in Journal/Newspaper |
author |
A. P. Roberts F. Florindo G. Villa L. Chang L. Jovane S. Bohaty J. C. Larrasoaña D. Heslop J. Fitz Gerald |
spellingShingle |
A. P. Roberts F. Florindo G. Villa L. Chang L. Jovane S. Bohaty J. C. Larrasoaña D. Heslop J. Fitz Gerald Magnetotactic bacterial abundance in pelagic marine environments is limited by organic carbon flux and availability of dissolved iron |
author_facet |
A. P. Roberts F. Florindo G. Villa L. Chang L. Jovane S. Bohaty J. C. Larrasoaña D. Heslop J. Fitz Gerald |
author_sort |
A. P. Roberts |
title |
Magnetotactic bacterial abundance in pelagic marine environments is limited by organic carbon flux and availability of dissolved iron |
title_short |
Magnetotactic bacterial abundance in pelagic marine environments is limited by organic carbon flux and availability of dissolved iron |
title_full |
Magnetotactic bacterial abundance in pelagic marine environments is limited by organic carbon flux and availability of dissolved iron |
title_fullStr |
Magnetotactic bacterial abundance in pelagic marine environments is limited by organic carbon flux and availability of dissolved iron |
title_full_unstemmed |
Magnetotactic bacterial abundance in pelagic marine environments is limited by organic carbon flux and availability of dissolved iron |
title_sort |
magnetotactic bacterial abundance in pelagic marine environments is limited by organic carbon flux and availability of dissolved iron |
publishDate |
2011 |
url |
http://hdl.handle.net/11381/2368099 https://doi.org/10.1016/j.epsl.2011.08.011 |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000298273500029 volume:310 firstpage:441 lastpage:452 numberofpages:12 journal:EARTH AND PLANETARY SCIENCE LETTERS http://hdl.handle.net/11381/2368099 doi:10.1016/j.epsl.2011.08.011 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-80053381935 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1016/j.epsl.2011.08.011 |
container_title |
Earth and Planetary Science Letters |
container_volume |
310 |
container_issue |
3-4 |
container_start_page |
441 |
op_container_end_page |
452 |
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1796932247432986624 |