| Título: | 40Ar/39Ar laserprobe dating of mylonitic fabrics in a polyorogenic terrane ofNW Iberia |
| Autores: | Gómez Barreiro, Juan ; Wijbrans, Jan R. ; Castiñeiras García, Pedro ; Martínez Catalán, José R. ; Arenas Martín, Ricardo ; Díaz García, Florentino ; Abati Gómez, Jacobo |
| Tipo de documento: | texto impreso |
| Editorial: | Geological Society of London., 2006 |
| Dimensiones: | application/pdf |
| Nota general: | info:eu-repo/semantics/openAccess |
| Idiomas: | |
| Palabras clave: | Estado = Publicado , Materia = Ciencias: Geología: Petrología , Tipo = Artículo |
| Resumen: |
The tectonothermal evolution of a polyorogenic terrane in the Variscan belt of NW Spain has been constrained by 40Ar/39Ar laserprobe incremental heating experiments on mylonitic fabrics developed in major structures. Transitional levels between HP–HT and IP upper units in the O´ rdenes Complex where metamorphic and structural records demonstrate two cycles of burial and exhumation were selected for dating. Two groups of ages have been defined: (1) Silurian–Early Devonian, obtained from mylonites of the Forna´s extensional detachment, here considered as the minimum age for the start of tectonic exhumation of the HP– HT units and an upper age-limit for the HP–HT event itself; (2) Early to Mid-Devonian, from structures related to the Variscan convergence in the area, which include top-to-the-east thrusts and extensional detachments. A single, younger Carboniferous age obtained from the uppermost allochthonous sequences possibly reflects the final stages of emplacement of the allochthonous complexes. Our data indicate a polyorogenic character for a part of the Iberian allochthonous complexes, including Variscan (sensu stricto) and Early Variscan convergence, as well as an older, Early Palaeozoic cycle. |
| En línea: | https://eprints.ucm.es/id/eprint/14028/1/Gomez_Barreiro_et_al_06_%28Ar-Ar%29_01.pdf |
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