Análisis estructural de los mármoles de la banda metamórfica de Aracena (Macizo Ibérico meridional). Implicaciones tectónicas regionales

Abstract

The structural analysis of marbles from the Aracena metamorphic belt has proven to be very useful to deduce the structure and the tectonic evolution of the continental domain of this belt, which, in turn, is a key area in the understanding of the Iberian Massif and the Varsican Belt. The layering of the marbles from the continental domain (DC-S0) is defined by a compositional banding along with several boudinaged calc-silicate and amphibolitic layers. The morphology of these boudins implies that the calc-silicate and amphibolitic layers are much more competent than the sorrounding marble. Also, the boudinage structures suggest that they were formed by stretching parallel to the layering, probably related to axial flattening (DC-D) Both the layering and the main metamorphic foliation (DC-S2) generated during DC-D2 were affected by open folds of the third deformational event (DC-D3) and later, by shear zones developed during the last dutile event recorded in the continental domain (DC-D4), which gave place to a tectonic breccia of rigid calc-silicate clasts sorrounded by a ductile marble matrix