Primitive helium and neon isotopes in Terceira island (Azores archipelago)
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10174/2378 |
Resumo: | We present the first neon data, as well as new helium data, on Terceira Island (Azores archipelago, Portugal). Clear 20Ne and 21Ne excesses compared to air are observed (20Ne/22Ne > 11.2) and moreover, the samples show a more primitive 21Ne/22Ne ratio than MORB, confirming that the Azores hotspot can be considered as sampling a “primitive”, relatively undegassed, reservoir. Most 4He/3He isotopic ratios range between 80,000 and 63,500 (not, vert, similar 9 to 11.5 R/Ra), being similar to those previously reported by [1] [M. Moreira, R. Doucelance, B. Dupré, M. Kurz, C.J. Allègre, Helium and lead isotope geochemistry in the Azores archipelago, Earth Planet. Sci. Lett. 169 (1999) 189–205] . A more primitive 4He/3He ratio of not, vert, similar 50,000 (R/Ra not, vert, similar 15) was obtained in one sample, but we cannot completely exclude the possibility of a cosmogenic 3He contribution for this sample. Our study illustrates that the neon systematics can be more capable than helium to constrain the ultimate origin of hotspots in geodynamic settings dominated by plume–ridge interaction. |
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Primitive helium and neon isotopes in Terceira island (Azores archipelago)Gases rarosAçoresWe present the first neon data, as well as new helium data, on Terceira Island (Azores archipelago, Portugal). Clear 20Ne and 21Ne excesses compared to air are observed (20Ne/22Ne > 11.2) and moreover, the samples show a more primitive 21Ne/22Ne ratio than MORB, confirming that the Azores hotspot can be considered as sampling a “primitive”, relatively undegassed, reservoir. Most 4He/3He isotopic ratios range between 80,000 and 63,500 (not, vert, similar 9 to 11.5 R/Ra), being similar to those previously reported by [1] [M. Moreira, R. Doucelance, B. Dupré, M. Kurz, C.J. Allègre, Helium and lead isotope geochemistry in the Azores archipelago, Earth Planet. Sci. Lett. 169 (1999) 189–205] . A more primitive 4He/3He ratio of not, vert, similar 50,000 (R/Ra not, vert, similar 15) was obtained in one sample, but we cannot completely exclude the possibility of a cosmogenic 3He contribution for this sample. Our study illustrates that the neon systematics can be more capable than helium to constrain the ultimate origin of hotspots in geodynamic settings dominated by plume–ridge interaction.Elsevier2010-12-28T11:01:01Z2010-12-282005-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article14262 bytesapplication/mswordhttp://hdl.handle.net/10174/2378http://hdl.handle.net/10174/2378eng429-440233Earth and Planetary Science Letters233livrepedro@uevora.ptndndndEarth and Planetary Science Letters396MADUREIRA, PedroMOREIRA, P.MATA, MJ. ALLÈGRE, C. J.info: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:RCAAP2024-01-03T18:37:48Zoai:dspace.uevora.pt:10174/2378Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T00:57:40.633754Repositório 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 |
Primitive helium and neon isotopes in Terceira island (Azores archipelago) |
title |
Primitive helium and neon isotopes in Terceira island (Azores archipelago) |
spellingShingle |
Primitive helium and neon isotopes in Terceira island (Azores archipelago) MADUREIRA, Pedro Gases raros Açores |
title_short |
Primitive helium and neon isotopes in Terceira island (Azores archipelago) |
title_full |
Primitive helium and neon isotopes in Terceira island (Azores archipelago) |
title_fullStr |
Primitive helium and neon isotopes in Terceira island (Azores archipelago) |
title_full_unstemmed |
Primitive helium and neon isotopes in Terceira island (Azores archipelago) |
title_sort |
Primitive helium and neon isotopes in Terceira island (Azores archipelago) |
author |
MADUREIRA, Pedro |
author_facet |
MADUREIRA, Pedro MOREIRA, P. MATA, M J. ALLÈGRE, C. J. |
author_role |
author |
author2 |
MOREIRA, P. MATA, M J. ALLÈGRE, C. J. |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
MADUREIRA, Pedro MOREIRA, P. MATA, M J. ALLÈGRE, C. J. |
dc.subject.por.fl_str_mv |
Gases raros Açores |
topic |
Gases raros Açores |
description |
We present the first neon data, as well as new helium data, on Terceira Island (Azores archipelago, Portugal). Clear 20Ne and 21Ne excesses compared to air are observed (20Ne/22Ne > 11.2) and moreover, the samples show a more primitive 21Ne/22Ne ratio than MORB, confirming that the Azores hotspot can be considered as sampling a “primitive”, relatively undegassed, reservoir. Most 4He/3He isotopic ratios range between 80,000 and 63,500 (not, vert, similar 9 to 11.5 R/Ra), being similar to those previously reported by [1] [M. Moreira, R. Doucelance, B. Dupré, M. Kurz, C.J. Allègre, Helium and lead isotope geochemistry in the Azores archipelago, Earth Planet. Sci. Lett. 169 (1999) 189–205] . A more primitive 4He/3He ratio of not, vert, similar 50,000 (R/Ra not, vert, similar 15) was obtained in one sample, but we cannot completely exclude the possibility of a cosmogenic 3He contribution for this sample. Our study illustrates that the neon systematics can be more capable than helium to constrain the ultimate origin of hotspots in geodynamic settings dominated by plume–ridge interaction. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005-01-01T00:00:00Z 2010-12-28T11:01:01Z 2010-12-28 |
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/10174/2378 http://hdl.handle.net/10174/2378 |
url |
http://hdl.handle.net/10174/2378 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
429-440 233 Earth and Planetary Science Letters 233 livre pedro@uevora.pt nd nd nd Earth and Planetary Science Letters 396 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
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14262 bytes application/msword |
dc.publisher.none.fl_str_mv |
Elsevier |
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Elsevier |
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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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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799136460991889408 |