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Aragonite dissolution protects calcite at the seafloor
In the open ocean, calcium carbonates are mainly found in two mineral forms. Calcite, the least soluble, is widespread at the seafloor, while aragonite, the more soluble, is rarely preserved in marine sediments. Despite its greater solubility, research has shown that aragonite, whose contribution to...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8888755/ https://www.ncbi.nlm.nih.gov/pubmed/35232971 http://dx.doi.org/10.1038/s41467-022-28711-z |
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author | Sulpis, Olivier Agrawal, Priyanka Wolthers, Mariette Munhoven, Guy Walker, Matthew Middelburg, Jack J. |
author_facet | Sulpis, Olivier Agrawal, Priyanka Wolthers, Mariette Munhoven, Guy Walker, Matthew Middelburg, Jack J. |
author_sort | Sulpis, Olivier |
collection | PubMed |
description | In the open ocean, calcium carbonates are mainly found in two mineral forms. Calcite, the least soluble, is widespread at the seafloor, while aragonite, the more soluble, is rarely preserved in marine sediments. Despite its greater solubility, research has shown that aragonite, whose contribution to global pelagic calcification could be at par with that of calcite, is able to reach the deep-ocean. If large quantities of aragonite settle and dissolve at the seafloor, this represents a large source of alkalinity that buffers the deep ocean and favours the preservation of less soluble calcite, acting as a deep-sea, carbonate version of galvanization. Here, we investigate the role of aragonite dissolution on the early diagenesis of calcite-rich sediments using a novel 3D, micrometric-scale reactive-transport model combined with 3D, X-ray tomography structures of natural aragonite and calcite shells. Results highlight the important role of diffusive transport in benthic calcium carbonate dissolution, in agreement with recent work. We show that, locally, aragonite fluxes to the seafloor could be sufficient to suppress calcite dissolution in the top layer of the seabed, possibly causing calcite recrystallization. As aragonite producers are particularly vulnerable to ocean acidification, the proposed galvanizing effect of aragonite could be weakened in the future, and calcite dissolution at the sediment-water interface will have to cover a greater share of CO(2) neutralization. |
format | Online Article Text |
id | pubmed-8888755 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-88887552022-03-17 Aragonite dissolution protects calcite at the seafloor Sulpis, Olivier Agrawal, Priyanka Wolthers, Mariette Munhoven, Guy Walker, Matthew Middelburg, Jack J. Nat Commun Article In the open ocean, calcium carbonates are mainly found in two mineral forms. Calcite, the least soluble, is widespread at the seafloor, while aragonite, the more soluble, is rarely preserved in marine sediments. Despite its greater solubility, research has shown that aragonite, whose contribution to global pelagic calcification could be at par with that of calcite, is able to reach the deep-ocean. If large quantities of aragonite settle and dissolve at the seafloor, this represents a large source of alkalinity that buffers the deep ocean and favours the preservation of less soluble calcite, acting as a deep-sea, carbonate version of galvanization. Here, we investigate the role of aragonite dissolution on the early diagenesis of calcite-rich sediments using a novel 3D, micrometric-scale reactive-transport model combined with 3D, X-ray tomography structures of natural aragonite and calcite shells. Results highlight the important role of diffusive transport in benthic calcium carbonate dissolution, in agreement with recent work. We show that, locally, aragonite fluxes to the seafloor could be sufficient to suppress calcite dissolution in the top layer of the seabed, possibly causing calcite recrystallization. As aragonite producers are particularly vulnerable to ocean acidification, the proposed galvanizing effect of aragonite could be weakened in the future, and calcite dissolution at the sediment-water interface will have to cover a greater share of CO(2) neutralization. Nature Publishing Group UK 2022-03-01 /pmc/articles/PMC8888755/ /pubmed/35232971 http://dx.doi.org/10.1038/s41467-022-28711-z Text en © The Author(s) 2022 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Sulpis, Olivier Agrawal, Priyanka Wolthers, Mariette Munhoven, Guy Walker, Matthew Middelburg, Jack J. Aragonite dissolution protects calcite at the seafloor |
title | Aragonite dissolution protects calcite at the seafloor |
title_full | Aragonite dissolution protects calcite at the seafloor |
title_fullStr | Aragonite dissolution protects calcite at the seafloor |
title_full_unstemmed | Aragonite dissolution protects calcite at the seafloor |
title_short | Aragonite dissolution protects calcite at the seafloor |
title_sort | aragonite dissolution protects calcite at the seafloor |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8888755/ https://www.ncbi.nlm.nih.gov/pubmed/35232971 http://dx.doi.org/10.1038/s41467-022-28711-z |
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