Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard
Neodymium (Nd) isotopes in leached authigenic components of marine sediments have been increasingly used as a tracer of past ocean-water masses. Despite the general assumption that the Nd isotopic composition of solutes released during chemical weathering fingerprints the source rocks on continents,...
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Online Access: | https://archimer.ifremer.fr/doc/00630/74176/75784.pdf https://doi.org/10.1016/j.epsl.2020.116319 https://archimer.ifremer.fr/doc/00630/74176/ |
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ftarchimer:oai:archimer.ifremer.fr:74176 2023-05-15T16:22:08+02:00 Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard Jang, Kwangchul Bayon, Germain Han, Yeongcheol Joo, Young Ji Kim, Ji-hoon Ryu, Jong-sik Woo, Jusun Forwick, Matthias Szczuciński, Witold Kim, Jung-hyun Nam, Seung-il 2020-07 application/pdf https://archimer.ifremer.fr/doc/00630/74176/75784.pdf https://doi.org/10.1016/j.epsl.2020.116319 https://archimer.ifremer.fr/doc/00630/74176/ eng eng Elsevier BV https://archimer.ifremer.fr/doc/00630/74176/75784.pdf doi:10.1016/j.epsl.2020.116319 https://archimer.ifremer.fr/doc/00630/74176/ info:eu-repo/semantics/openAccess restricted use Earth And Planetary Science Letters (0012-821X) (Elsevier BV), 2020-07 , Vol. 542 , P. 116319 (12p.) neodymium isotopes isotopic decoupling incongruent weathering glacier fluctuation Svalbard text Publication info:eu-repo/semantics/article 2020 ftarchimer https://doi.org/10.1016/j.epsl.2020.116319 2021-09-23T20:35:08Z Neodymium (Nd) isotopes in leached authigenic components of marine sediments have been increasingly used as a tracer of past ocean-water masses. Despite the general assumption that the Nd isotopic composition of solutes released during chemical weathering fingerprints the source rocks on continents, preferential dissolution of easily dissolvable phases may result in significant deviations in Nd isotopic composition between the solutes and the source rocks, with potential implications for the utility of Nd isotopes in paleoenvironmental studies. Here, we present the Nd isotopic compositions of leached and detrital fractions separated from bedrock and marine sediment samples from the Svalbard archipelago. Our goal is to further understand the behaviour of Nd isotopes during chemical weathering in glacial catchments and evaluate how glacier fluctuations and associated weathering congruency may have affected the export of dissolved Nd isotope signatures to seawater. Our results confirm that terrestrial weathering on Svalbard causes considerable Nd isotopic decoupling between the leached and detrital fractions of fjord sediments (△εNd), resulting from the preferential dissolution of marine precipitates in glaciated catchments dominated by sedimentary rocks. We also show that the degree of Nd isotopic decoupling has fluctuated in response to climate variability on Svalbard during the Holocene, which is also as suggested by the occurrence of generally higher △εNd values during periods of glacier advances in sediment cores retrieved from two different fjords (Dicksonfjorden and Woodfjorden). We posit that the high △εNd values can be ascribed to incongruent chemical weathering of fresh rock flour produced by glacial abrasion. This finding suggests that the degree of Nd isotopic decoupling could be used as a new proxy for tracing glacial fluctuations and associated glacier-derived nutrient inputs to the marine realm. Article in Journal/Newspaper glacier Svalbard Woodfjord* Woodfjorden Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Dicksonfjorden ENVELOPE(15.291,15.291,78.710,78.710) Svalbard Svalbard Archipelago Woodfjorden ENVELOPE(14.000,14.000,79.833,79.833) Earth and Planetary Science Letters 542 116319 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
neodymium isotopes isotopic decoupling incongruent weathering glacier fluctuation Svalbard |
spellingShingle |
neodymium isotopes isotopic decoupling incongruent weathering glacier fluctuation Svalbard Jang, Kwangchul Bayon, Germain Han, Yeongcheol Joo, Young Ji Kim, Ji-hoon Ryu, Jong-sik Woo, Jusun Forwick, Matthias Szczuciński, Witold Kim, Jung-hyun Nam, Seung-il Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard |
topic_facet |
neodymium isotopes isotopic decoupling incongruent weathering glacier fluctuation Svalbard |
description |
Neodymium (Nd) isotopes in leached authigenic components of marine sediments have been increasingly used as a tracer of past ocean-water masses. Despite the general assumption that the Nd isotopic composition of solutes released during chemical weathering fingerprints the source rocks on continents, preferential dissolution of easily dissolvable phases may result in significant deviations in Nd isotopic composition between the solutes and the source rocks, with potential implications for the utility of Nd isotopes in paleoenvironmental studies. Here, we present the Nd isotopic compositions of leached and detrital fractions separated from bedrock and marine sediment samples from the Svalbard archipelago. Our goal is to further understand the behaviour of Nd isotopes during chemical weathering in glacial catchments and evaluate how glacier fluctuations and associated weathering congruency may have affected the export of dissolved Nd isotope signatures to seawater. Our results confirm that terrestrial weathering on Svalbard causes considerable Nd isotopic decoupling between the leached and detrital fractions of fjord sediments (△εNd), resulting from the preferential dissolution of marine precipitates in glaciated catchments dominated by sedimentary rocks. We also show that the degree of Nd isotopic decoupling has fluctuated in response to climate variability on Svalbard during the Holocene, which is also as suggested by the occurrence of generally higher △εNd values during periods of glacier advances in sediment cores retrieved from two different fjords (Dicksonfjorden and Woodfjorden). We posit that the high △εNd values can be ascribed to incongruent chemical weathering of fresh rock flour produced by glacial abrasion. This finding suggests that the degree of Nd isotopic decoupling could be used as a new proxy for tracing glacial fluctuations and associated glacier-derived nutrient inputs to the marine realm. |
format |
Article in Journal/Newspaper |
author |
Jang, Kwangchul Bayon, Germain Han, Yeongcheol Joo, Young Ji Kim, Ji-hoon Ryu, Jong-sik Woo, Jusun Forwick, Matthias Szczuciński, Witold Kim, Jung-hyun Nam, Seung-il |
author_facet |
Jang, Kwangchul Bayon, Germain Han, Yeongcheol Joo, Young Ji Kim, Ji-hoon Ryu, Jong-sik Woo, Jusun Forwick, Matthias Szczuciński, Witold Kim, Jung-hyun Nam, Seung-il |
author_sort |
Jang, Kwangchul |
title |
Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard |
title_short |
Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard |
title_full |
Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard |
title_fullStr |
Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard |
title_full_unstemmed |
Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard |
title_sort |
neodymium isotope constraints on chemical weathering and past glacial activity in svalbard |
publisher |
Elsevier BV |
publishDate |
2020 |
url |
https://archimer.ifremer.fr/doc/00630/74176/75784.pdf https://doi.org/10.1016/j.epsl.2020.116319 https://archimer.ifremer.fr/doc/00630/74176/ |
long_lat |
ENVELOPE(15.291,15.291,78.710,78.710) ENVELOPE(14.000,14.000,79.833,79.833) |
geographic |
Dicksonfjorden Svalbard Svalbard Archipelago Woodfjorden |
geographic_facet |
Dicksonfjorden Svalbard Svalbard Archipelago Woodfjorden |
genre |
glacier Svalbard Woodfjord* Woodfjorden |
genre_facet |
glacier Svalbard Woodfjord* Woodfjorden |
op_source |
Earth And Planetary Science Letters (0012-821X) (Elsevier BV), 2020-07 , Vol. 542 , P. 116319 (12p.) |
op_relation |
https://archimer.ifremer.fr/doc/00630/74176/75784.pdf doi:10.1016/j.epsl.2020.116319 https://archimer.ifremer.fr/doc/00630/74176/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1016/j.epsl.2020.116319 |
container_title |
Earth and Planetary Science Letters |
container_volume |
542 |
container_start_page |
116319 |
_version_ |
1766010109263085568 |