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...
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ftunivutrecht:oai:dspace.library.uu.nl:1874/418421 2023-07-23T04:21:11+02:00 Aragonite dissolution protects calcite at the seafloor Sulpis, Olivier Agrawal, Priyanka Wolthers, Mariette Munhoven, Guy Walker, Matthew Middelburg, Jack J Geochemistry General geochemistry 2022-03-01 application/pdf https://dspace.library.uu.nl/handle/1874/418421 en eng 2041-1723 https://dspace.library.uu.nl/handle/1874/418421 info:eu-repo/semantics/OpenAccess Chemistry(all) Biochemistry Genetics and Molecular Biology(all) Physics and Astronomy(all) Article 2022 ftunivutrecht 2023-07-02T03:36:39Z 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 CO2 neutralization. Article in Journal/Newspaper Ocean acidification Utrecht University Repository |
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Open Polar |
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Utrecht University Repository |
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ftunivutrecht |
language |
English |
topic |
Chemistry(all) Biochemistry Genetics and Molecular Biology(all) Physics and Astronomy(all) |
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Chemistry(all) Biochemistry Genetics and Molecular Biology(all) Physics and Astronomy(all) Sulpis, Olivier Agrawal, Priyanka Wolthers, Mariette Munhoven, Guy Walker, Matthew Middelburg, Jack J Aragonite dissolution protects calcite at the seafloor |
topic_facet |
Chemistry(all) Biochemistry Genetics and Molecular Biology(all) Physics and Astronomy(all) |
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 CO2 neutralization. |
author2 |
Geochemistry General geochemistry |
format |
Article in Journal/Newspaper |
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 |
title |
Aragonite dissolution protects calcite at the seafloor |
title_short |
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_sort |
aragonite dissolution protects calcite at the seafloor |
publishDate |
2022 |
url |
https://dspace.library.uu.nl/handle/1874/418421 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
2041-1723 https://dspace.library.uu.nl/handle/1874/418421 |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1772186464327565312 |