Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71.
Autor(a) principal: | |
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Data de Publicação: | 2014 |
Outros Autores: | , , , , , , |
Tipo de documento: | Artigo |
Idioma: | por |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10174/13518 https://doi.org/10.1016/j.chemgeo.2014.02.015 |
Resumo: | We present new He isotopic data from subaerial and submarine samples collected along the Terceira Rift (Azores Plateau) in order to constrain the sources involved in the Azoresmagmatismin the unique geodynamic contextof the Azores triple junction. Lower thanMORB 4He/3He isotopic ratioswere determined on olivines fromthe Terceira Island and the adjacent Serreta submarine ridge (down to≈69,000;≈10.5 R/Ra),which in addition to the Ne isotopes previously published inMadureira et al. (2005) [Primitive heliumand neon isotopes in Terceira Island: Constraints on the origin of the Azores archipelago. Earth and Planetary Science Letters 233, 429–440], support the geochemical models that consider the involvement of the lower mantle in the Azores magmatism. The analysis of He data published for the Mid-Atlantic Ridge (MAR) points to the existence of chemically distinct mantle domains underneath Eurasia and Nubia lithospheric plates, which can result from an heterogeneous distribution of asthenosphere metasomatism during the initial stages of plume activity in the Azores region. At the Terceira Rift, lavas from Graciosa Island, as well as from the western end of São Miguel Island and D. João de Castro Bank, display 4He/3He ratios similar to those observed along the MAR segments located to the north of the Azores triple junction area. Conversely, samples from the south Hirondelle Basin and also Faial display a He isotopic signature similar to that of MORB erupted along MAR segments located to the south of the Azores Plateau. The Terceira Rift and the Azores triple junction area are thus characterized by the mingling of two different asthenospheric domains referred as “Eurasia” and “Nubia” type and by the presence of mantle plume derived material having primitive helium signature. |
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Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71.He isotopesTerceira RiftEurasia-Nubia boundaryAzores Triple JunctionWe present new He isotopic data from subaerial and submarine samples collected along the Terceira Rift (Azores Plateau) in order to constrain the sources involved in the Azoresmagmatismin the unique geodynamic contextof the Azores triple junction. Lower thanMORB 4He/3He isotopic ratioswere determined on olivines fromthe Terceira Island and the adjacent Serreta submarine ridge (down to≈69,000;≈10.5 R/Ra),which in addition to the Ne isotopes previously published inMadureira et al. (2005) [Primitive heliumand neon isotopes in Terceira Island: Constraints on the origin of the Azores archipelago. Earth and Planetary Science Letters 233, 429–440], support the geochemical models that consider the involvement of the lower mantle in the Azores magmatism. The analysis of He data published for the Mid-Atlantic Ridge (MAR) points to the existence of chemically distinct mantle domains underneath Eurasia and Nubia lithospheric plates, which can result from an heterogeneous distribution of asthenosphere metasomatism during the initial stages of plume activity in the Azores region. At the Terceira Rift, lavas from Graciosa Island, as well as from the western end of São Miguel Island and D. João de Castro Bank, display 4He/3He ratios similar to those observed along the MAR segments located to the north of the Azores triple junction area. Conversely, samples from the south Hirondelle Basin and also Faial display a He isotopic signature similar to that of MORB erupted along MAR segments located to the south of the Azores Plateau. The Terceira Rift and the Azores triple junction area are thus characterized by the mingling of two different asthenospheric domains referred as “Eurasia” and “Nubia” type and by the presence of mantle plume derived material having primitive helium signature.Chemical Geology2015-03-24T10:40:29Z2015-03-242014-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10174/13518http://hdl.handle.net/10174/13518https://doi.org/10.1016/j.chemgeo.2014.02.015porpedro@uevora.ptmoreira@ipgp.frjmata@fc.ul.ptndndndndnd396Madureira, PedroMoreira, ManuelMata, JoãoNunes, João CarlosGautheron, CecileLourenço, NunoCarvalho, Maria do RosárioPinto de Abreu, Manuelinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-01-03T18:58:59Zoai:dspace.uevora.pt:10174/13518Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T01:06:55.631138Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71. |
title |
Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71. |
spellingShingle |
Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71. Madureira, Pedro He isotopes Terceira Rift Eurasia-Nubia boundary Azores Triple Junction |
title_short |
Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71. |
title_full |
Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71. |
title_fullStr |
Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71. |
title_full_unstemmed |
Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71. |
title_sort |
Helium isotope systematics in the vicinity of the Azores triple junction: Constraints on the Azores geodynamics. Chemical Geology, 372, 62-71. |
author |
Madureira, Pedro |
author_facet |
Madureira, Pedro Moreira, Manuel Mata, João Nunes, João Carlos Gautheron, Cecile Lourenço, Nuno Carvalho, Maria do Rosário Pinto de Abreu, Manuel |
author_role |
author |
author2 |
Moreira, Manuel Mata, João Nunes, João Carlos Gautheron, Cecile Lourenço, Nuno Carvalho, Maria do Rosário Pinto de Abreu, Manuel |
author2_role |
author author author author author author author |
dc.contributor.author.fl_str_mv |
Madureira, Pedro Moreira, Manuel Mata, João Nunes, João Carlos Gautheron, Cecile Lourenço, Nuno Carvalho, Maria do Rosário Pinto de Abreu, Manuel |
dc.subject.por.fl_str_mv |
He isotopes Terceira Rift Eurasia-Nubia boundary Azores Triple Junction |
topic |
He isotopes Terceira Rift Eurasia-Nubia boundary Azores Triple Junction |
description |
We present new He isotopic data from subaerial and submarine samples collected along the Terceira Rift (Azores Plateau) in order to constrain the sources involved in the Azoresmagmatismin the unique geodynamic contextof the Azores triple junction. Lower thanMORB 4He/3He isotopic ratioswere determined on olivines fromthe Terceira Island and the adjacent Serreta submarine ridge (down to≈69,000;≈10.5 R/Ra),which in addition to the Ne isotopes previously published inMadureira et al. (2005) [Primitive heliumand neon isotopes in Terceira Island: Constraints on the origin of the Azores archipelago. Earth and Planetary Science Letters 233, 429–440], support the geochemical models that consider the involvement of the lower mantle in the Azores magmatism. The analysis of He data published for the Mid-Atlantic Ridge (MAR) points to the existence of chemically distinct mantle domains underneath Eurasia and Nubia lithospheric plates, which can result from an heterogeneous distribution of asthenosphere metasomatism during the initial stages of plume activity in the Azores region. At the Terceira Rift, lavas from Graciosa Island, as well as from the western end of São Miguel Island and D. João de Castro Bank, display 4He/3He ratios similar to those observed along the MAR segments located to the north of the Azores triple junction area. Conversely, samples from the south Hirondelle Basin and also Faial display a He isotopic signature similar to that of MORB erupted along MAR segments located to the south of the Azores Plateau. The Terceira Rift and the Azores triple junction area are thus characterized by the mingling of two different asthenospheric domains referred as “Eurasia” and “Nubia” type and by the presence of mantle plume derived material having primitive helium signature. |
publishDate |
2014 |
dc.date.none.fl_str_mv |
2014-01-01T00:00:00Z 2015-03-24T10:40:29Z 2015-03-24 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10174/13518 http://hdl.handle.net/10174/13518 https://doi.org/10.1016/j.chemgeo.2014.02.015 |
url |
http://hdl.handle.net/10174/13518 https://doi.org/10.1016/j.chemgeo.2014.02.015 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.none.fl_str_mv |
pedro@uevora.pt moreira@ipgp.fr jmata@fc.ul.pt nd nd nd nd nd 396 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Chemical Geology |
publisher.none.fl_str_mv |
Chemical Geology |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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