Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases
The occurrence of manganese-rich coatings on foraminifera can have a significant effect on their bulk Mg/Ca ratios thereby biasing seawater temperature reconstructions. The removal of this Mn phase requires a reductive cleaning step, but this has been suggested to preferentially dissolve Mg-rich bio...
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ftucambridgeesc:oai:eprints.esc.cam.ac.uk:4009 2023-05-15T13:55:44+02:00 Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases Hasenfratz, Adam P. Martínez-García, Alfredo Jaccard, Samuel L. Vance, Derek Wälle, Markus Greaves, Mervyn Haug, Gerald H. 2017 text http://eprints.esc.cam.ac.uk/4009/ http://eprints.esc.cam.ac.uk/4009/1/1-s2.0-S0012821X16305532-main.pdf https://doi.org/10.1016/j.epsl.2016.10.004 en eng Elsevier http://eprints.esc.cam.ac.uk/4009/1/1-s2.0-S0012821X16305532-main.pdf Hasenfratz, Adam P. and Martínez-García, Alfredo and Jaccard, Samuel L. and Vance, Derek and Wälle, Markus and Greaves, Mervyn and Haug, Gerald H. (2017) Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases. Earth and Planetary Science Letters, 457. pp. 335-347. ISSN 0012-821X DOI https://doi.org/10.1016/j.epsl.2016.10.004 <https://doi.org/10.1016/j.epsl.2016.10.004> 01 - Climate Change and Earth-Ocean Atmosphere Systems Article PeerReviewed 2017 ftucambridgeesc https://doi.org/10.1016/j.epsl.2016.10.004 2020-08-27T18:09:52Z The occurrence of manganese-rich coatings on foraminifera can have a significant effect on their bulk Mg/Ca ratios thereby biasing seawater temperature reconstructions. The removal of this Mn phase requires a reductive cleaning step, but this has been suggested to preferentially dissolve Mg-rich biogenic carbonate, potentially introducing an analytical bias in paleotemperature estimates. In this study, the geochemical composition of foraminifera tests from Mn-rich sediments from the Antarctic Southern Ocean (ODP Site 1094) was investigated using solution-based and laser ablation ICP-MS in order to determine the amount of Mg incorporated into the coatings. The analysis of planktonic and benthic foraminifera revealed a nearly constant Mg/Mn ratio in the Mn coating of ∼0.2 mol/mol. Consequently, the coating Mg/Mn ratio can be used to correct for the Mg incorporated into the Mn phase by using the down core Mn/Ca values of samples that have not been reductively cleaned. The consistency of the coating Mg/Mn ratio obtained in this study, as well as that found in samples from the Panama Basin, suggests that spatial variation of Mg/Mn in foraminiferal Mn overgrowths may be smaller than expected from Mn nodules and Mn–Ca carbonates. However, a site-specific assessment of the Mg/Mn ratio in foraminiferal coatings is recommended to improve the accuracy of the correction. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean University of Cambridge, Department of Earth Sciences: ESC Publications Antarctic Southern Ocean The Antarctic Earth and Planetary Science Letters 457 335 347 |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
spellingShingle |
01 - Climate Change and Earth-Ocean Atmosphere Systems Hasenfratz, Adam P. Martínez-García, Alfredo Jaccard, Samuel L. Vance, Derek Wälle, Markus Greaves, Mervyn Haug, Gerald H. Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases |
topic_facet |
01 - Climate Change and Earth-Ocean Atmosphere Systems |
description |
The occurrence of manganese-rich coatings on foraminifera can have a significant effect on their bulk Mg/Ca ratios thereby biasing seawater temperature reconstructions. The removal of this Mn phase requires a reductive cleaning step, but this has been suggested to preferentially dissolve Mg-rich biogenic carbonate, potentially introducing an analytical bias in paleotemperature estimates. In this study, the geochemical composition of foraminifera tests from Mn-rich sediments from the Antarctic Southern Ocean (ODP Site 1094) was investigated using solution-based and laser ablation ICP-MS in order to determine the amount of Mg incorporated into the coatings. The analysis of planktonic and benthic foraminifera revealed a nearly constant Mg/Mn ratio in the Mn coating of ∼0.2 mol/mol. Consequently, the coating Mg/Mn ratio can be used to correct for the Mg incorporated into the Mn phase by using the down core Mn/Ca values of samples that have not been reductively cleaned. The consistency of the coating Mg/Mn ratio obtained in this study, as well as that found in samples from the Panama Basin, suggests that spatial variation of Mg/Mn in foraminiferal Mn overgrowths may be smaller than expected from Mn nodules and Mn–Ca carbonates. However, a site-specific assessment of the Mg/Mn ratio in foraminiferal coatings is recommended to improve the accuracy of the correction. |
format |
Article in Journal/Newspaper |
author |
Hasenfratz, Adam P. Martínez-García, Alfredo Jaccard, Samuel L. Vance, Derek Wälle, Markus Greaves, Mervyn Haug, Gerald H. |
author_facet |
Hasenfratz, Adam P. Martínez-García, Alfredo Jaccard, Samuel L. Vance, Derek Wälle, Markus Greaves, Mervyn Haug, Gerald H. |
author_sort |
Hasenfratz, Adam P. |
title |
Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases |
title_short |
Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases |
title_full |
Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases |
title_fullStr |
Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases |
title_full_unstemmed |
Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases |
title_sort |
determination of the mg/mn ratio in foraminiferal coatings: an approach to correct mg/ca temperatures for mn-rich contaminant phases |
publisher |
Elsevier |
publishDate |
2017 |
url |
http://eprints.esc.cam.ac.uk/4009/ http://eprints.esc.cam.ac.uk/4009/1/1-s2.0-S0012821X16305532-main.pdf https://doi.org/10.1016/j.epsl.2016.10.004 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
http://eprints.esc.cam.ac.uk/4009/1/1-s2.0-S0012821X16305532-main.pdf Hasenfratz, Adam P. and Martínez-García, Alfredo and Jaccard, Samuel L. and Vance, Derek and Wälle, Markus and Greaves, Mervyn and Haug, Gerald H. (2017) Determination of the Mg/Mn ratio in foraminiferal coatings: An approach to correct Mg/Ca temperatures for Mn-rich contaminant phases. Earth and Planetary Science Letters, 457. pp. 335-347. ISSN 0012-821X DOI https://doi.org/10.1016/j.epsl.2016.10.004 <https://doi.org/10.1016/j.epsl.2016.10.004> |
op_doi |
https://doi.org/10.1016/j.epsl.2016.10.004 |
container_title |
Earth and Planetary Science Letters |
container_volume |
457 |
container_start_page |
335 |
op_container_end_page |
347 |
_version_ |
1766262577323573248 |