Comparación entre las direcciones de anisotropía de la susceptibilidad magnética (ASM) y la lineación de estiramiento estructural en las peridotitas de Ronda: hacia un método identificador de lineaciones en ausencia de marcadores en rocas ultramáficas

Abstract

The Betic-Rif cordillera constitutes the western most part of the Alpine orogeny in the Mediterranean area. Its formation and structural evolution are widely debated. An important piece of information is the origin and emplacement of the ultramafic bodies that outcrop in both sides of the cordillera. The bodies in the northern part, known as Ronda peridotites, have been studied from the structural point of view in order to elaborate geodynamical models. A study of the anisotropy of magnetic susceptibility (AMS) has been carried out with further correlation between the magnetic lineation and structural stretching lineation measured in the field. Additional rock magnetic measurements have allowed determining the carriers of the magnetic signal. Magnetite originated during the serpentinization process, has been identified as the main carrier of the magnetic susceptibility. The positive correlation between magnetic lineation and stretching lineation makes the method suitable for the evaluation of structural directions in the absence of other markers.