Argumentos petrológicos y geoquímicos para la subdivisión del Complejo Nevado-Filábride en los Complejos del Veleta y del Mulhacén

Resumo

The Veleta and Mulhacén Complexes, previously considered together as the Nevado-Filábride Complex, constitute the deepest units of the Betic Cordilleras. The Veleta Complex (VC) is mainly formed of several thousand metres of graphite-bearing micaschists and crops out as a series of tectonic windows below the Mulhacén Complex (MC). This latter complex comprises a pile of thrust nappes of crustal origin, composed of a Palaeozoic basement and Mesozoic cover series, between which a Jurassic-Cretaceous ophiolitic nappe is tectonically intercalated. Within the MC nappes of crustal origin, meta-granitic rocks occur, generated in a late-Eiercynian syn-collisional magmatism and a Permian to Triassic, post-collisional intraplate, acidic-to-in ter mediate volcanism. The ophiolitic nappe is composed o f basic, ultramafic and sedimentary rocks affected by ocean-floor and orogenic metamorphism. The basic rocks mainly retain their original E-MORB character. The ultramafic rocks are serpentinites and secondary harzburgites containing partly rodingitized basaltic dykes. The Soportújar Formation of the MC is made up of continental meta-sediments and meta-andesitic rocks originated during an intra-orogenic relaxation period between the eo-Alpine and meso-Alpine metamorphic events. The Alpine metamorphism developed in eclogite facies followed by Ab-Ep amphibolite facies in the MC, and in Ab-Ep amphibolite facies followed by greenschist facies in the VC.