Constraints on the source of reactive phases in sediment from a major Arctic river using neodymium isotopes
International audience Riverine suspended particulate matter (SPM) is essential for the delivery of micronutrients such as iron (Fe) to the oceans. SPM is known to consist of multiple phases with differing reactivity, but their role in the delivery of elements to the oceans is poorly constrained. He...
Published in: | Earth and Planetary Science Letters |
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Online Access: | https://hal.science/hal-04203477 https://doi.org/10.1016/j.epsl.2021.116933 |
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ftunivparis:oai:HAL:hal-04203477v1 2024-05-12T07:59:25+00:00 Constraints on the source of reactive phases in sediment from a major Arctic river using neodymium isotopes Larkin, Christina S. Piotrowski, Alexander M. Hindshaw, Ruth S. Bayon, Germain Hilton, Robert G. Baronas, J. Jotautas Dellinger, Mathieu Wang, Ruixue Tipper, Edward T. Unité Géosciences Marines (GM) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) Institut de Physique du Globe de Paris (IPGP (UMR_7154)) Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) 2021-07 https://hal.science/hal-04203477 https://doi.org/10.1016/j.epsl.2021.116933 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2021.116933 hal-04203477 https://hal.science/hal-04203477 doi:10.1016/j.epsl.2021.116933 ISSN: 0012-821X Earth and Planetary Science Letters https://hal.science/hal-04203477 Earth and Planetary Science Letters, 2021, 565, 116933 (11p.). ⟨10.1016/j.epsl.2021.116933⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2021 ftunivparis https://doi.org/10.1016/j.epsl.2021.116933 2024-04-16T02:53:07Z International audience Riverine suspended particulate matter (SPM) is essential for the delivery of micronutrients such as iron (Fe) to the oceans. SPM is known to consist of multiple phases with differing reactivity, but their role in the delivery of elements to the oceans is poorly constrained. Here we provide new constraints on the source and composition of reactive phases in SPM from the Mackenzie River, the largest sediment source to the Arctic Ocean. Sequential leaching of SPM shows that river sediments contain labile Fe phases. We estimate the labile Fe flux is substantial (0.21(+0.06,-0.05) Tg/yr) by quantifying Fe concentrations in weak leaches of the SPM. The labile Fe phase hosts a considerable amount of rare earth elements (REE), including neodymium (Nd). We demonstrate that the labile Fe phase and dissolved load have radiogenic Nd isotope ratios that are identical within uncertainty, but up to 8 epsilon units distinct from the silicate phase. We interpret this as evidence for dynamic cycling between Fe-oxide phases in SPM and the river water, demonstrating the high reactivity of the labile Fe phase. Nd isotope and elemental molar ratios suggest that a significant amount of labile Fe- and Nd-bearing phases are derived from Fe-oxides within the sedimentary source rock rather than silicate mineral dissolution. Thus, sedimentary rock erosion and weathering provides an important source of labile Fe, manganese (Mn) and by extension potentially other trace metals. Our results imply that both past and future environmental change in the Arctic, such as permafrost thaw, may trigger changes to the supply of reactive trace metals. These results demonstrate that a re-evaluation of sediment reactivity within rivers is required where uplifted sedimentary rocks are present. Article in Journal/Newspaper Arctic Arctic Ocean Mackenzie river permafrost Université de Paris: Portail HAL Arctic Arctic Ocean Mackenzie River Earth and Planetary Science Letters 565 116933 |
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Open Polar |
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Université de Paris: Portail HAL |
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ftunivparis |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Larkin, Christina S. Piotrowski, Alexander M. Hindshaw, Ruth S. Bayon, Germain Hilton, Robert G. Baronas, J. Jotautas Dellinger, Mathieu Wang, Ruixue Tipper, Edward T. Constraints on the source of reactive phases in sediment from a major Arctic river using neodymium isotopes |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience Riverine suspended particulate matter (SPM) is essential for the delivery of micronutrients such as iron (Fe) to the oceans. SPM is known to consist of multiple phases with differing reactivity, but their role in the delivery of elements to the oceans is poorly constrained. Here we provide new constraints on the source and composition of reactive phases in SPM from the Mackenzie River, the largest sediment source to the Arctic Ocean. Sequential leaching of SPM shows that river sediments contain labile Fe phases. We estimate the labile Fe flux is substantial (0.21(+0.06,-0.05) Tg/yr) by quantifying Fe concentrations in weak leaches of the SPM. The labile Fe phase hosts a considerable amount of rare earth elements (REE), including neodymium (Nd). We demonstrate that the labile Fe phase and dissolved load have radiogenic Nd isotope ratios that are identical within uncertainty, but up to 8 epsilon units distinct from the silicate phase. We interpret this as evidence for dynamic cycling between Fe-oxide phases in SPM and the river water, demonstrating the high reactivity of the labile Fe phase. Nd isotope and elemental molar ratios suggest that a significant amount of labile Fe- and Nd-bearing phases are derived from Fe-oxides within the sedimentary source rock rather than silicate mineral dissolution. Thus, sedimentary rock erosion and weathering provides an important source of labile Fe, manganese (Mn) and by extension potentially other trace metals. Our results imply that both past and future environmental change in the Arctic, such as permafrost thaw, may trigger changes to the supply of reactive trace metals. These results demonstrate that a re-evaluation of sediment reactivity within rivers is required where uplifted sedimentary rocks are present. |
author2 |
Unité Géosciences Marines (GM) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) Institut de Physique du Globe de Paris (IPGP (UMR_7154)) Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) |
format |
Article in Journal/Newspaper |
author |
Larkin, Christina S. Piotrowski, Alexander M. Hindshaw, Ruth S. Bayon, Germain Hilton, Robert G. Baronas, J. Jotautas Dellinger, Mathieu Wang, Ruixue Tipper, Edward T. |
author_facet |
Larkin, Christina S. Piotrowski, Alexander M. Hindshaw, Ruth S. Bayon, Germain Hilton, Robert G. Baronas, J. Jotautas Dellinger, Mathieu Wang, Ruixue Tipper, Edward T. |
author_sort |
Larkin, Christina S. |
title |
Constraints on the source of reactive phases in sediment from a major Arctic river using neodymium isotopes |
title_short |
Constraints on the source of reactive phases in sediment from a major Arctic river using neodymium isotopes |
title_full |
Constraints on the source of reactive phases in sediment from a major Arctic river using neodymium isotopes |
title_fullStr |
Constraints on the source of reactive phases in sediment from a major Arctic river using neodymium isotopes |
title_full_unstemmed |
Constraints on the source of reactive phases in sediment from a major Arctic river using neodymium isotopes |
title_sort |
constraints on the source of reactive phases in sediment from a major arctic river using neodymium isotopes |
publisher |
HAL CCSD |
publishDate |
2021 |
url |
https://hal.science/hal-04203477 https://doi.org/10.1016/j.epsl.2021.116933 |
geographic |
Arctic Arctic Ocean Mackenzie River |
geographic_facet |
Arctic Arctic Ocean Mackenzie River |
genre |
Arctic Arctic Ocean Mackenzie river permafrost |
genre_facet |
Arctic Arctic Ocean Mackenzie river permafrost |
op_source |
ISSN: 0012-821X Earth and Planetary Science Letters https://hal.science/hal-04203477 Earth and Planetary Science Letters, 2021, 565, 116933 (11p.). ⟨10.1016/j.epsl.2021.116933⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2021.116933 hal-04203477 https://hal.science/hal-04203477 doi:10.1016/j.epsl.2021.116933 |
op_doi |
https://doi.org/10.1016/j.epsl.2021.116933 |
container_title |
Earth and Planetary Science Letters |
container_volume |
565 |
container_start_page |
116933 |
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1798840717697613824 |