Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionation

Selenium behaves as a chalcophile and moderately volatile element during planetary accretion and magmatic processes on Earth. Together with the geochemically similar S and Te, Se is more volatile than most other moderately volatile elements and thus potentially becomes a new tracer to constrain the...

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Autores: Yierpan, Aierken, Redlinger, Johannes, König, Stephan
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/276298
Acceso en línea:http://hdl.handle.net/10261/276298
Access Level:acceso abierto
Palabra clave:Degassing
Icelandic plume
Isotope fractionation
MORB
Plume-ridge interaction
Selenium
Tellurium
Volatile loss
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network_acronym_str ES
network_name_str España
repository_id_str
dc.title.none.fl_str_mv Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionation
title Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionation
spellingShingle Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionation
Yierpan, Aierken
Degassing
Icelandic plume
Isotope fractionation
MORB
Plume-ridge interaction
Selenium
Tellurium
Volatile loss
title_short Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionation
title_full Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionation
title_fullStr Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionation
title_full_unstemmed Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionation
title_sort Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionation
dc.creator.none.fl_str_mv Yierpan, Aierken
Redlinger, Johannes
König, Stephan
author Yierpan, Aierken
author_facet Yierpan, Aierken
Redlinger, Johannes
König, Stephan
author_role author
author2 Redlinger, Johannes
König, Stephan
author2_role author
author
dc.contributor.none.fl_str_mv European Commission
European Research Council
Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Degassing
Icelandic plume
Isotope fractionation
MORB
Plume-ridge interaction
Selenium
Tellurium
Volatile loss
topic Degassing
Icelandic plume
Isotope fractionation
MORB
Plume-ridge interaction
Selenium
Tellurium
Volatile loss
description Selenium behaves as a chalcophile and moderately volatile element during planetary accretion and magmatic processes on Earth. Together with the geochemically similar S and Te, Se is more volatile than most other moderately volatile elements and thus potentially becomes a new tracer to constrain the mechanism of volatile depletion in the Earth's mantle and other planetary bodies. As previously observed for several volatile elements, stable isotopes of Se are expected to fractionate upon eruptive outgassing of magmas. To understand the degassing behavior of Se and associated isotope fractionation, we report on Se and Te contents and Se isotope compositions (δSe) of submarine glasses across a range of distant ridge depth intervals along the Reykjanes Ridge and subglacial/subaerial basalts on Iceland (51–65°N; N = 22). Selenium (150–399 ng/g) and Te (2.61–14.5 ng/g) contents of the submarine glasses display progressive enrichment along the Reykjanes Ridge towards Iceland. This can be explained either by enhanced mantle melting towards Iceland or by enrichment of Se–Te contents in the mantle source due to the Icelandic plume–Reykjanes Ridge interaction. Both scenarios are equally plausible. The δSe values of submarine Reykjanes Ridge glasses range between −0.20 ± 0.08‰ and −0.08 ± 0.08‰ (on average −0.15 ± 0.07‰; 2SD, N = 15), which are unaffected by the Icelandic plume contribution and remain strictly within the previously reported average for depleted MORBs. These new data combined with literature δSe for depleted MORBs define a highly homogeneous depleted mantle composition δSe = −0.15 ± 0.11‰ (2SD, N = 44). On the other hand, we observed degassing of Se and Te to a variable extent (~40–95%) in submarine Reykjanes glasses at depths shallower than ~250 m and in subaerial/subglacial basalts on Iceland. Degassing-induced Se isotope fractionation shifted δSe of subaerial lavas towards heavier values (by up to ~0.44‰) well outside the range of submarine MORBs. However, when Se outgassing is associated with subglacial eruption, the outer glass rim of basalt preserves the primary/undegassed Se isotopic signature; whereas the pillow interior experiencing further Se loss (~50%) is enriched in heavier isotopes (−0.01 ± 0.12‰) relative to the outer glass rim (−0.22 ± 0.08‰). These observations are complemented by measurements of BHVO-2G from high-temperature heating experiments of the natural Hawaiian basalt BHVO-2, which show evaporation of 40% Se and 85% Te and resulting shift in δSe by ~+0.74‰. Degassing-induced Se isotope fractionation during volcanic eruption may be well explained by a simple Rayleigh distillation model with an empirical fractionation factor α of ~0.9998 (between volcanic gas and silicate melt). The results presented here show that Se isotope and Se–Te systematics can potentially contribute further constraints on degassing of chalcophile and volatile elements during terrestrial volcanism and large-scale planetary processes.
publishDate 2021
dc.date.none.fl_str_mv 2021
2022
2022
2022
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Postprint
info:eu-repo/semantics/acceptedVersion
format article
status_str acceptedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/276298
url http://hdl.handle.net/10261/276298
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv #PLACEHOLDER_PARENT_METADATA_VALUE#
info:eu-repo/grantAgreement/EC/H2020/636808
http://dx.doi.org/10.1016/j.gca.2021.07.029

dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Elsevier BV
publisher.none.fl_str_mv Elsevier BV
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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spelling Selenium and tellurium in Reykjanes Ridge and Icelandic basalts: Evidence for degassing-induced Se isotope fractionationYierpan, AierkenRedlinger, JohannesKönig, StephanDegassingIcelandic plumeIsotope fractionationMORBPlume-ridge interactionSeleniumTelluriumVolatile lossSelenium behaves as a chalcophile and moderately volatile element during planetary accretion and magmatic processes on Earth. Together with the geochemically similar S and Te, Se is more volatile than most other moderately volatile elements and thus potentially becomes a new tracer to constrain the mechanism of volatile depletion in the Earth's mantle and other planetary bodies. As previously observed for several volatile elements, stable isotopes of Se are expected to fractionate upon eruptive outgassing of magmas. To understand the degassing behavior of Se and associated isotope fractionation, we report on Se and Te contents and Se isotope compositions (δSe) of submarine glasses across a range of distant ridge depth intervals along the Reykjanes Ridge and subglacial/subaerial basalts on Iceland (51–65°N; N = 22). Selenium (150–399 ng/g) and Te (2.61–14.5 ng/g) contents of the submarine glasses display progressive enrichment along the Reykjanes Ridge towards Iceland. This can be explained either by enhanced mantle melting towards Iceland or by enrichment of Se–Te contents in the mantle source due to the Icelandic plume–Reykjanes Ridge interaction. Both scenarios are equally plausible. The δSe values of submarine Reykjanes Ridge glasses range between −0.20 ± 0.08‰ and −0.08 ± 0.08‰ (on average −0.15 ± 0.07‰; 2SD, N = 15), which are unaffected by the Icelandic plume contribution and remain strictly within the previously reported average for depleted MORBs. These new data combined with literature δSe for depleted MORBs define a highly homogeneous depleted mantle composition δSe = −0.15 ± 0.11‰ (2SD, N = 44). On the other hand, we observed degassing of Se and Te to a variable extent (~40–95%) in submarine Reykjanes glasses at depths shallower than ~250 m and in subaerial/subglacial basalts on Iceland. Degassing-induced Se isotope fractionation shifted δSe of subaerial lavas towards heavier values (by up to ~0.44‰) well outside the range of submarine MORBs. However, when Se outgassing is associated with subglacial eruption, the outer glass rim of basalt preserves the primary/undegassed Se isotopic signature; whereas the pillow interior experiencing further Se loss (~50%) is enriched in heavier isotopes (−0.01 ± 0.12‰) relative to the outer glass rim (−0.22 ± 0.08‰). These observations are complemented by measurements of BHVO-2G from high-temperature heating experiments of the natural Hawaiian basalt BHVO-2, which show evaporation of 40% Se and 85% Te and resulting shift in δSe by ~+0.74‰. Degassing-induced Se isotope fractionation during volcanic eruption may be well explained by a simple Rayleigh distillation model with an empirical fractionation factor α of ~0.9998 (between volcanic gas and silicate melt). The results presented here show that Se isotope and Se–Te systematics can potentially contribute further constraints on degassing of chalcophile and volatile elements during terrestrial volcanism and large-scale planetary processes.We are especially grateful to Jean-Guy Schilling for his initial support and encouragement of the project, and to Katherine A. Kelley for providing us with all the samples. We acknowledge fruitful discussions with Ronny Schoenberg, Jabrane Labidi, and Timon Kurzawa, and lab support from Elmar Reitter and Maria Isabel Varas-Reus. We also thank Frances Jenner, Alex McCoy-West, and an anonymous reviewer for their through reviews and constructive suggestions, and Julie Prytulak for the efficient editorial handling. S. K. acknowledges financial support by the ERC Starting Grant O2RIGIN (636808).Peer reviewedElsevier BVEuropean CommissionEuropean Research CouncilConsejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]2022202220212022info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Postprintinfo:eu-repo/semantics/acceptedVersionhttp://hdl.handle.net/10261/276298reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglés#PLACEHOLDER_PARENT_METADATA_VALUE#info:eu-repo/grantAgreement/EC/H2020/636808http://dx.doi.org/10.1016/j.gca.2021.07.029Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/2762982026-05-22T06:33:51Z
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