Fábricas y texturas miloníticas. Cinemática de las traslaciones en el complejo Nevado-Filábride (Cordilleras Béticas, España)

Abstract

In the Nevado-Filábride Units of the Eastern Sierra Nevada, the main structure is a mylonitic foliation with a strong stretching lineation. The trend of this 1ineation shows a bimodal orientation resulting from two successive phases of deformation (D₂, N80E and D₃, NI45E).
A comparative study of the structures and microestructures developed in both phases is presented. The relations between metamorphism and deformation are also considered.
A kinematic analisis of the Nevado-Filábride displacements from the c-axis fabrics of quartz is induded. Microstructures and crystallographic preferred orientations of quartz suggest that quartzites were deformed by intracrystalline plasticity with dislocation creep.
A first conclusion suggest that the Nevado-Filábride pile is attained after- two main stages of thrusting. In the first, a major intra-crustal shear zone separating the Mulhacén Nappe (high presure and moderate temperature metamorphism) from the underlying Veleta Nappe (low presure and low temperature metamorphism) is developed. In the second one the former pile is disturbed and the imbrication of the units belonging to the upper part of the Complex occurred.