Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids
<jats:p>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...
Main Authors: | , , , , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Frontiers Media SA
2021
|
Subjects: | |
Online Access: | https://www.repository.cam.ac.uk/handle/1810/326657 https://doi.org/10.17863/CAM.74106 |
id |
ftunivcam:oai:www.repository.cam.ac.uk:1810/326657 |
---|---|
record_format |
openpolar |
spelling |
ftunivcam:oai:www.repository.cam.ac.uk:1810/326657 2024-01-14T10:09:07+01:00 Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids James, DH Bradbury, HJ Antler, G Steiner, Z Hutchings, AM Sun, X Saar, R Greaves, M Turchyn, AV 2021 application/pdf https://www.repository.cam.ac.uk/handle/1810/326657 https://doi.org/10.17863/CAM.74106 eng eng Frontiers Media SA http://dx.doi.org/10.3389/feart.2021.601194 Frontiers in Earth Science https://www.repository.cam.ac.uk/handle/1810/326657 doi:10.17863/CAM.74106 Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ carbonate precipitation calcium isotopes early diagenesis microbial sulfate reduction microbial iron reduction sedimentary boundary layer carbonate dissolution Article 2021 ftunivcam https://doi.org/10.17863/CAM.74106 2023-12-21T23:24:42Z <jats:p>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<jats:sup>44</jats:sup>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<jats:sup>44</jats:sup>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<jats:sup>44</jats:sup>Ca than previously thought.</jats:p> Article in Journal/Newspaper North Atlantic Apollo - University of Cambridge Repository |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
carbonate precipitation calcium isotopes early diagenesis microbial sulfate reduction microbial iron reduction sedimentary boundary layer carbonate dissolution |
spellingShingle |
carbonate precipitation calcium isotopes early diagenesis microbial sulfate reduction microbial iron reduction sedimentary boundary layer carbonate dissolution James, DH Bradbury, HJ Antler, G Steiner, Z Hutchings, AM Sun, X Saar, R Greaves, M Turchyn, AV Assessing Sedimentary Boundary Layer Calcium Carbonate Precipitation and Dissolution Using the Calcium Isotopic Composition of Pore Fluids |
topic_facet |
carbonate precipitation calcium isotopes early diagenesis microbial sulfate reduction microbial iron reduction sedimentary boundary layer carbonate dissolution |
description |
<jats:p>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<jats:sup>44</jats:sup>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<jats:sup>44</jats:sup>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<jats:sup>44</jats:sup>Ca than previously thought.</jats:p> |
format |
Article in Journal/Newspaper |
author |
James, DH Bradbury, HJ Antler, G Steiner, Z Hutchings, AM Sun, X Saar, R Greaves, M Turchyn, AV |
author_facet |
James, DH Bradbury, HJ Antler, G Steiner, Z Hutchings, AM Sun, X Saar, R Greaves, M Turchyn, AV |
author_sort |
James, DH |
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 Media SA |
publishDate |
2021 |
url |
https://www.repository.cam.ac.uk/handle/1810/326657 https://doi.org/10.17863/CAM.74106 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/326657 doi:10.17863/CAM.74106 |
op_rights |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.17863/CAM.74106 |
_version_ |
1788063581259956224 |