Evolución metamórfica de los esquitos de AP/BT de Ceán (Unidad de Malpica-Tui, NW del Macizo Ibérico)

Metapelitic schists from the upper structural levels of the Malpica-Tui Unit contain an initial blueschist facies mineral assemblage that appears mainly preserved as micro-inclusions in garnet, albite and chloritoid porphiroblasts defining a S1 foliation. The main foliation (S2 ) represents an evolu...

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Detalles Bibliográficos
Autores: López Carmona, Alicia, Abati Gómez, Jacobo, Reche i Estrada, Juan
Tipo de recurso: artículo
Fecha de publicación:2007
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:español
OAI Identifier:oai:docta.ucm.es:20.500.14352/103064
Acceso en línea:https://hdl.handle.net/20.500.14352/103064
Access Level:acceso abierto
Palabra clave:552.4(460)
Variscan Belt
Allochthonous Complexes
Malpica-Tui Unit
Blueschists facies
thermobarometry
Petrología
2506.13 Petrología Ignea y Metamórfica
Descripción
Sumario:Metapelitic schists from the upper structural levels of the Malpica-Tui Unit contain an initial blueschist facies mineral assemblage that appears mainly preserved as micro-inclusions in garnet, albite and chloritoid porphiroblasts defining a S1 foliation. The main foliation (S2 ) represents an evolution of the S1 to slightly higher temperature and lower pressure, but it is still developed in blueschist facies conditions. Post-S2 deformations include restricted development of spaced C’ shear bands, tight and straight D3 folds and a later gentle subhorizontal crenulation formed in greenschists facies conditions. Garnet-phengite thermometry and GRIPS and GASP barometry calculations, using micro-inclusion compositions, indicate peak conditions around P=19-22 Kbar and T=430-500 ºC. The same calculations using the S2 fabric minerals yield approximate values of P=16-19 Kbar and T=440-515 ºC.