Giant magnetofossils and hyperthermal events
Magnetotactic bacteria biomineralize magnetic minerals with precisely controlled size, morphology, and stoichiometry. These cosmopolitan bacteria are widely observed in aquatic environments. If preserved after burial, the inorganic remains of magnetotactic bacteria act as magnetofossils that record...
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ftcsic:oai:digital.csic.es:10261/277030 2024-02-11T09:56:14+01:00 Giant magnetofossils and hyperthermal events Liao, Chang Roberts, Andrew P. Williams, Wyn Fitz Gerald, John D. Larrasoaña, Juan C. Jovane, Luigi Muxworthy, Adrian R. Océano Antártico y Océano Índico 2012-09-03 http://hdl.handle.net/10261/277030 https://doi.org/10.1016/j.epsl.2012.07.031 en eng Elsevier https://www.sciencedirect.com/science/article/abs/pii/S0012821X12004062 Earth and Planetary Science Letters, vol.351-352, 258-269 1385-013X http://hdl.handle.net/10261/277030 https://doi.org/10.1016/j.epsl.2012.07.031 open giant magnetofossils hyperthermal eukaryote magnetotactic bacteria Océano Antártico Océano Índico artículo 2012 ftcsic https://doi.org/10.1016/j.epsl.2012.07.031 2024-01-16T11:27:50Z Magnetotactic bacteria biomineralize magnetic minerals with precisely controlled size, morphology, and stoichiometry. These cosmopolitan bacteria are widely observed in aquatic environments. If preserved after burial, the inorganic remains of magnetotactic bacteria act as magnetofossils that record ancient geomagnetic field variations. They also have potential to provide paleoenvironmental information. In contrast to conventional magnetofossils, giant magnetofossils (most likely produced by eukaryotic organisms) have only been reported once before from Paleocene-Eocene Thermal Maximum (PETM; 55.8 Ma) sediments on the New Jersey coastal plain. Here, using transmission electron microscopic observations, we present evidence for abundant giant magnetofossils, including previously reported elongated prisms and spindles, and new giant bullet-shaped magnetite crystals, in the Southern Ocean near Antarctica, not only during the PETM, but also shortly before and after the PETM. Moreover, we have discovered giant bullet-shaped magnetite crystals from the equatorial Indian Ocean during the Mid-Eocene Climatic Optimum (∼40 Ma). Our results indicate a more widespread geographic, environmental, and temporal distribution of giant magnetofossils in the geological record with a link to “hyperthermal” events. Enhanced global weathering during hyperthermals, and expanded suboxic diagenetic environments, probably provided more bioavailable iron that enabled biomineralization of giant magnetofossils. Our micromagnetic modelling indicates the presence of magnetic multi-domain (i.e., not ideal for navigation) and single domain (i.e., ideal for navigation) structures in the giant magnetite particles depending on their size, morphology and spatial arrangement. Different giant magnetite crystal morphologies appear to have had different biological functions, including magnetotaxis and other non-navigational purposes. Our observations suggest that hyperthermals provided ideal conditions for giant magnetofossils, and that these organisms ... Article in Journal/Newspaper Antarc* Antarctica Southern Ocean Digital.CSIC (Spanish National Research Council) Indian Southern Ocean Earth and Planetary Science Letters 351-352 258 269 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
topic |
giant magnetofossils hyperthermal eukaryote magnetotactic bacteria Océano Antártico Océano Índico |
spellingShingle |
giant magnetofossils hyperthermal eukaryote magnetotactic bacteria Océano Antártico Océano Índico Liao, Chang Roberts, Andrew P. Williams, Wyn Fitz Gerald, John D. Larrasoaña, Juan C. Jovane, Luigi Muxworthy, Adrian R. Giant magnetofossils and hyperthermal events |
topic_facet |
giant magnetofossils hyperthermal eukaryote magnetotactic bacteria Océano Antártico Océano Índico |
description |
Magnetotactic bacteria biomineralize magnetic minerals with precisely controlled size, morphology, and stoichiometry. These cosmopolitan bacteria are widely observed in aquatic environments. If preserved after burial, the inorganic remains of magnetotactic bacteria act as magnetofossils that record ancient geomagnetic field variations. They also have potential to provide paleoenvironmental information. In contrast to conventional magnetofossils, giant magnetofossils (most likely produced by eukaryotic organisms) have only been reported once before from Paleocene-Eocene Thermal Maximum (PETM; 55.8 Ma) sediments on the New Jersey coastal plain. Here, using transmission electron microscopic observations, we present evidence for abundant giant magnetofossils, including previously reported elongated prisms and spindles, and new giant bullet-shaped magnetite crystals, in the Southern Ocean near Antarctica, not only during the PETM, but also shortly before and after the PETM. Moreover, we have discovered giant bullet-shaped magnetite crystals from the equatorial Indian Ocean during the Mid-Eocene Climatic Optimum (∼40 Ma). Our results indicate a more widespread geographic, environmental, and temporal distribution of giant magnetofossils in the geological record with a link to “hyperthermal” events. Enhanced global weathering during hyperthermals, and expanded suboxic diagenetic environments, probably provided more bioavailable iron that enabled biomineralization of giant magnetofossils. Our micromagnetic modelling indicates the presence of magnetic multi-domain (i.e., not ideal for navigation) and single domain (i.e., ideal for navigation) structures in the giant magnetite particles depending on their size, morphology and spatial arrangement. Different giant magnetite crystal morphologies appear to have had different biological functions, including magnetotaxis and other non-navigational purposes. Our observations suggest that hyperthermals provided ideal conditions for giant magnetofossils, and that these organisms ... |
format |
Article in Journal/Newspaper |
author |
Liao, Chang Roberts, Andrew P. Williams, Wyn Fitz Gerald, John D. Larrasoaña, Juan C. Jovane, Luigi Muxworthy, Adrian R. |
author_facet |
Liao, Chang Roberts, Andrew P. Williams, Wyn Fitz Gerald, John D. Larrasoaña, Juan C. Jovane, Luigi Muxworthy, Adrian R. |
author_sort |
Liao, Chang |
title |
Giant magnetofossils and hyperthermal events |
title_short |
Giant magnetofossils and hyperthermal events |
title_full |
Giant magnetofossils and hyperthermal events |
title_fullStr |
Giant magnetofossils and hyperthermal events |
title_full_unstemmed |
Giant magnetofossils and hyperthermal events |
title_sort |
giant magnetofossils and hyperthermal events |
publisher |
Elsevier |
publishDate |
2012 |
url |
http://hdl.handle.net/10261/277030 https://doi.org/10.1016/j.epsl.2012.07.031 |
op_coverage |
Océano Antártico y Océano Índico |
geographic |
Indian Southern Ocean |
geographic_facet |
Indian Southern Ocean |
genre |
Antarc* Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctica Southern Ocean |
op_relation |
https://www.sciencedirect.com/science/article/abs/pii/S0012821X12004062 Earth and Planetary Science Letters, vol.351-352, 258-269 1385-013X http://hdl.handle.net/10261/277030 https://doi.org/10.1016/j.epsl.2012.07.031 |
op_rights |
open |
op_doi |
https://doi.org/10.1016/j.epsl.2012.07.031 |
container_title |
Earth and Planetary Science Letters |
container_volume |
351-352 |
container_start_page |
258 |
op_container_end_page |
269 |
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1790601560151031808 |