Zonas de cizalla dúctil en el Complejo Basal de Fuerteventura

Abstract

The oldest plutonic rocks of the Basal Complex of the Fuerteventura Island In the area of Amanay are an alkaline ultramafic-carbonatite complex. In certain areas these rocks are affected by two ductile shear systems with respectively general NW-SE and NE-SW orientations. The deformation related to these shear zones originate, in certain instances, a marked mylonitic foliation and the formation of folds that change notabily the structures and textures of the affected rocks. The geometric relation that exist between these structures and the location of the gravimetric and magnetic anomalies of the Island, its oceanic counterpart as well as the morphology of the sedimentary basins located to the N and NW, may point to the existence of Important oceanic fractures in this sector of the North Atlantic.