Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids
We present pore fluid geochemistry, including major ion and trace metal concentrations and the isotopic composition of pore fluid calcium and sulfate, from the uppermost meter of sediments from the Gulf of Aqaba (Northeast Red Sea) and the Iberian Margin (North Atlantic Ocean). In both the locations...
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ftoceanrep:oai:oceanrep.geomar.de:53699 2024-02-11T10:06:30+01:00 Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids James, Daniel H. Bradbury, Harold J. Antler, Gilad Steiner, Zvi Hutchings, Alec M. Sun, Xiaole Saar, Raoul Greaves, Mervyn Turchyn, Alexandra V. 2021-08-05 text archive https://oceanrep.geomar.de/id/eprint/53699/ https://oceanrep.geomar.de/id/eprint/53699/1/feart-09-601194.pdf https://oceanrep.geomar.de/id/eprint/53699/2/5544765.zip https://doi.org/10.3389/feart.2021.601194 en eng Frontiers https://oceanrep.geomar.de/id/eprint/53699/1/feart-09-601194.pdf https://oceanrep.geomar.de/id/eprint/53699/2/5544765.zip James, D. H., Bradbury, H. J., Antler, G., Steiner, Z. , Hutchings, A. M., Sun, X., Saar, R., Greaves, M. and Turchyn, A. V. (2021) Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids. Open Access Frontiers in Earth Science, 9 (601194). DOI 10.3389/feart.2021.601194 <https://doi.org/10.3389/feart.2021.601194>. doi:10.3389/feart.2021.601194 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2021 ftoceanrep https://doi.org/10.3389/feart.2021.601194 2024-01-15T00:23:45Z We present pore fluid geochemistry, including major ion and trace metal concentrations and the isotopic composition of pore fluid calcium and sulfate, from the uppermost meter of sediments from the Gulf of Aqaba (Northeast Red Sea) and the Iberian Margin (North Atlantic Ocean). In both the locations, we observe strong correlations among calcium, magnesium, strontium, and sulfate concentrations as well as the sulfur isotopic composition of sulfate and alkalinity, suggestive of active changes in the redox state and pH that should lead to carbonate mineral precipitation and dissolution. The calcium isotope composition of pore fluid calcium (δ 44 Ca) is, however, relatively invariant in our measured profiles, suggesting that carbonate mineral precipitation is not occurring within the boundary layer at these sites. We explore several reasons why the pore fluid δ 44 Ca might not be changing in the studied profiles, despite changes in other major ions and their isotopic composition, including mixing between the surface and deep precipitation of carbonate minerals below the boundary layer, the possibility that active iron and manganese cycling inhibits carbonate mineral precipitation, and that mineral precipitation may be slow enough to preclude calcium isotope fractionation during carbonate mineral precipitation. Our results suggest that active carbonate dissolution and precipitation, particularly in the diffusive boundary layer, may elicit a more complex response in the pore fluid δ 44 Ca than previously thought. Article in Journal/Newspaper North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Frontiers in Earth Science 9 |
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Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
We present pore fluid geochemistry, including major ion and trace metal concentrations and the isotopic composition of pore fluid calcium and sulfate, from the uppermost meter of sediments from the Gulf of Aqaba (Northeast Red Sea) and the Iberian Margin (North Atlantic Ocean). In both the locations, we observe strong correlations among calcium, magnesium, strontium, and sulfate concentrations as well as the sulfur isotopic composition of sulfate and alkalinity, suggestive of active changes in the redox state and pH that should lead to carbonate mineral precipitation and dissolution. The calcium isotope composition of pore fluid calcium (δ 44 Ca) is, however, relatively invariant in our measured profiles, suggesting that carbonate mineral precipitation is not occurring within the boundary layer at these sites. We explore several reasons why the pore fluid δ 44 Ca might not be changing in the studied profiles, despite changes in other major ions and their isotopic composition, including mixing between the surface and deep precipitation of carbonate minerals below the boundary layer, the possibility that active iron and manganese cycling inhibits carbonate mineral precipitation, and that mineral precipitation may be slow enough to preclude calcium isotope fractionation during carbonate mineral precipitation. Our results suggest that active carbonate dissolution and precipitation, particularly in the diffusive boundary layer, may elicit a more complex response in the pore fluid δ 44 Ca than previously thought. |
format |
Article in Journal/Newspaper |
author |
James, Daniel H. Bradbury, Harold J. Antler, Gilad Steiner, Zvi Hutchings, Alec M. Sun, Xiaole Saar, Raoul Greaves, Mervyn Turchyn, Alexandra V. |
spellingShingle |
James, Daniel H. Bradbury, Harold J. Antler, Gilad Steiner, Zvi Hutchings, Alec M. Sun, Xiaole Saar, Raoul Greaves, Mervyn Turchyn, Alexandra V. Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids |
author_facet |
James, Daniel H. Bradbury, Harold J. Antler, Gilad Steiner, Zvi Hutchings, Alec M. Sun, Xiaole Saar, Raoul Greaves, Mervyn Turchyn, Alexandra V. |
author_sort |
James, Daniel H. |
title |
Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids |
title_short |
Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids |
title_full |
Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids |
title_fullStr |
Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids |
title_full_unstemmed |
Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids |
title_sort |
assessing sedimentary boundary layer calcium carbonate precipitation and dissolution using the calcium isotopic composition of pore fluids |
publisher |
Frontiers |
publishDate |
2021 |
url |
https://oceanrep.geomar.de/id/eprint/53699/ https://oceanrep.geomar.de/id/eprint/53699/1/feart-09-601194.pdf https://oceanrep.geomar.de/id/eprint/53699/2/5544765.zip https://doi.org/10.3389/feart.2021.601194 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/53699/1/feart-09-601194.pdf https://oceanrep.geomar.de/id/eprint/53699/2/5544765.zip James, D. H., Bradbury, H. J., Antler, G., Steiner, Z. , Hutchings, A. M., Sun, X., Saar, R., Greaves, M. and Turchyn, A. V. (2021) Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids. Open Access Frontiers in Earth Science, 9 (601194). DOI 10.3389/feart.2021.601194 <https://doi.org/10.3389/feart.2021.601194>. doi:10.3389/feart.2021.601194 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.3389/feart.2021.601194 |
container_title |
Frontiers in Earth Science |
container_volume |
9 |
_version_ |
1790604262849380352 |