Ribbon texture and deformation mechanisms of quartz in a mylonitized granite of great kabylia (Algeria)

Abstract

A late hercynian granite situated in the Great Kabylia blastomylonitic belt was mylonitized along a dextral shear at high temperature during the last tectonic pulse. The behaviour of quartz in narrow (1 to 10 m) shear zones under the shear gradient was studied. The evolution of the microstructure from coarse to fine-grained ribbon texture is described and then discussed in terms of possible deformation mechanisms. Finally, a possible superplastic behaviour of fine-grained mylonite at the center of shear zones is considered.