Lithogeochemistry of metabasites from the Moura Phyllonitic Complex (Ossa Morena Zone, SW Portugal)

• Autor(a) principal: ROSEIRO, José
• Data de Publicação: 2019
• Outros Autores: Moreira, Noel, FONSECA, Rita, ARAÚJO, Alexandre, MAIA, Miguel, PEDRO, Jorge, NOGUEIRA, Pedro
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10174/27477
• topic: Zona de Ossa-Morena; Geoquímica; Moura Phylonitoc Complex; Metabasite

The Moura Phyllonitic Complex (MPC) is interpreted as a tectonic mélange that extends along the Montemor - Ficalho sector, overlaying the Relative Autochthone of the Ossa Morena Zone (Iberian Variscides, SW Portugal). Its northern boundary with the Estremoz-Barrancos sector is demarked by the Sto. Aleixo da Restauração Thrust. Generally, the MPC comprises several sericitic-chloritic and siliceous metasedimentary and metavolcanic rocks in a sheared matrix with unknown age, possible ranging from Cambrian to lower Devonian. Frequent imbrications of mafic suites with tholeiitic affinities are known within the MPC: obduction-related sequences, HP metamorphic rocks and dismembered volcanics interpreted as parautochthonous imbrications variably metamorphosed from lower-medium grade greenschist to amphibolite facies. Several of these metabasites were sampled for major and trace element ICP-OES analysis (prepared with alkaline fusion, acid digestion and cation-exchange chromatography), in order to characterize their geochemical variability and attempt to correlate with other autochthonous volcanic rocks, thus inferring their geodynamic setting.