Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca Ibérica
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/10174/2373 |
Resumo: | The Internal Ophiolitic Sequences correspond to allochthonous oceanic crust fragments that outcrop near the SW boundary of the Ossa-Morena Zone (Evora-Beja Domain), in an internal position relative to the Beja-Acebuches Ophiolitic Complex. The Internal Ophiolitic Sequences occur as tectonic imbrications or klippen, in the Moura Phyllonitic Complex. Despite deformation and metamorphism (greenschist/amphibolite facies), they still preserve a typical ophiolitic internal stratigraphy identical to the one described for many LOT (“Lherzolitic Ophiolite Type”) ophiolites. Geochemical data indicates that the Internal Ophiolitic Sequences have variable tholeiitic chemistry, transitional between N-MORB and E-MORB. Petrogenetic modelling suggests that the observed geochemical variations reflect both mantle source heterogeneity and partial melting processes. The Internal Ophiolitic Sequences geochemistry indicates that their igneous protholites formed in an anorogenic tectonomagmatic environment, like the ocean ridge basins, without any influence of orogenic components related to subduction mechanisms. These features contrast markedly with those reported for the Beja-Acebuches Ophiolitic Complex, which have been interpreted as representing oceanic crust generated in a “back-arc” setting,. Thus, supporting the existence of two distinct oceanic basins (ocean ridge and back-arc) during the geodynamical evolution of the SW Iberian Variscan Chain. Therefore, the Internal Ophiolitic Sequences in the Ossa-Morena Zone reflect the early oceanization events during the Variscan Orogeny. |
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Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca IbéricaInternal Ossa-Morena Zone Ophiolitic Sequences: geodynamic implications for the evolution of the SW branch of the Iberian Variscan ChainOphiolitesOssa-Morena ZoneMORBIberian Variscan ChainThe Internal Ophiolitic Sequences correspond to allochthonous oceanic crust fragments that outcrop near the SW boundary of the Ossa-Morena Zone (Evora-Beja Domain), in an internal position relative to the Beja-Acebuches Ophiolitic Complex. The Internal Ophiolitic Sequences occur as tectonic imbrications or klippen, in the Moura Phyllonitic Complex. Despite deformation and metamorphism (greenschist/amphibolite facies), they still preserve a typical ophiolitic internal stratigraphy identical to the one described for many LOT (“Lherzolitic Ophiolite Type”) ophiolites. Geochemical data indicates that the Internal Ophiolitic Sequences have variable tholeiitic chemistry, transitional between N-MORB and E-MORB. Petrogenetic modelling suggests that the observed geochemical variations reflect both mantle source heterogeneity and partial melting processes. The Internal Ophiolitic Sequences geochemistry indicates that their igneous protholites formed in an anorogenic tectonomagmatic environment, like the ocean ridge basins, without any influence of orogenic components related to subduction mechanisms. These features contrast markedly with those reported for the Beja-Acebuches Ophiolitic Complex, which have been interpreted as representing oceanic crust generated in a “back-arc” setting,. Thus, supporting the existence of two distinct oceanic basins (ocean ridge and back-arc) during the geodynamical evolution of the SW Iberian Variscan Chain. Therefore, the Internal Ophiolitic Sequences in the Ossa-Morena Zone reflect the early oceanization events during the Variscan Orogeny.2010-12-28T10:29:19Z2010-12-282005-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article1523602 bytesapplication/pdfhttp://hdl.handle.net/10174/2373http://hdl.handle.net/10174/2373eng235-2580231-4497Cadernos Lab. Xeolóxico de Laxe30livreCGEjpedro@uevora.ptndndnd250Pedro, JorgeAraújo, AlexandreFonseca, PauloMunhá, Joséinfo: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:RCAAP2024-01-03T18:38:40Zoai:dspace.uevora.pt:10174/2373Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T00:58:02.416362Repositório 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 |
Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca Ibérica Internal Ossa-Morena Zone Ophiolitic Sequences: geodynamic implications for the evolution of the SW branch of the Iberian Variscan Chain |
title |
Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca Ibérica |
spellingShingle |
Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca Ibérica Pedro, Jorge Ophiolites Ossa-Morena Zone MORB Iberian Variscan Chain |
title_short |
Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca Ibérica |
title_full |
Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca Ibérica |
title_fullStr |
Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca Ibérica |
title_full_unstemmed |
Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca Ibérica |
title_sort |
Sequências Ofiolíticas Internas da Zona de Ossa-Morena: implicações geodinâmicas na evolução da Cadeia Varisca Ibérica |
author |
Pedro, Jorge |
author_facet |
Pedro, Jorge Araújo, Alexandre Fonseca, Paulo Munhá, José |
author_role |
author |
author2 |
Araújo, Alexandre Fonseca, Paulo Munhá, José |
author2_role |
author author author |
dc.contributor.author.fl_str_mv |
Pedro, Jorge Araújo, Alexandre Fonseca, Paulo Munhá, José |
dc.subject.por.fl_str_mv |
Ophiolites Ossa-Morena Zone MORB Iberian Variscan Chain |
topic |
Ophiolites Ossa-Morena Zone MORB Iberian Variscan Chain |
description |
The Internal Ophiolitic Sequences correspond to allochthonous oceanic crust fragments that outcrop near the SW boundary of the Ossa-Morena Zone (Evora-Beja Domain), in an internal position relative to the Beja-Acebuches Ophiolitic Complex. The Internal Ophiolitic Sequences occur as tectonic imbrications or klippen, in the Moura Phyllonitic Complex. Despite deformation and metamorphism (greenschist/amphibolite facies), they still preserve a typical ophiolitic internal stratigraphy identical to the one described for many LOT (“Lherzolitic Ophiolite Type”) ophiolites. Geochemical data indicates that the Internal Ophiolitic Sequences have variable tholeiitic chemistry, transitional between N-MORB and E-MORB. Petrogenetic modelling suggests that the observed geochemical variations reflect both mantle source heterogeneity and partial melting processes. The Internal Ophiolitic Sequences geochemistry indicates that their igneous protholites formed in an anorogenic tectonomagmatic environment, like the ocean ridge basins, without any influence of orogenic components related to subduction mechanisms. These features contrast markedly with those reported for the Beja-Acebuches Ophiolitic Complex, which have been interpreted as representing oceanic crust generated in a “back-arc” setting,. Thus, supporting the existence of two distinct oceanic basins (ocean ridge and back-arc) during the geodynamical evolution of the SW Iberian Variscan Chain. Therefore, the Internal Ophiolitic Sequences in the Ossa-Morena Zone reflect the early oceanization events during the Variscan Orogeny. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005-01-01T00:00:00Z 2010-12-28T10:29:19Z 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/10174/2373 http://hdl.handle.net/10174/2373 |
url |
http://hdl.handle.net/10174/2373 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
235-258 0231-4497 Cadernos Lab. Xeolóxico de Laxe 30 livre CGE jpedro@uevora.pt nd nd nd 250 |
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info:eu-repo/semantics/openAccess |
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openAccess |
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1523602 bytes application/pdf |
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