Experiments and simulation evaluation of quartzite textures in the Córdoba sierra, Argentina

A.L. FOURTY; H.-G. BROKMEIER; R.D. MARTINO; R.E. BOLMARO

Z. Kristallographie

Zeitscrhrift für Kristallographie

Lugar: Oldenbourg Verlag, München; Año: 2009 vol. 30 p. 123 - 129

0044-2968

Texture characterization of deformed rocks allows the confirmation of kinematically determined deformation processes occurring during geologic events at plate margins and in intraplate settings. The understanding of such processes is of both basic and economical importance to decipher deformation regimes, mechanisms and Presure- Temperature (PT) conditions. The Guamanes Deformation Belt (GDB) is a shear zone at Sierras de Córdoba (Argentina) which extends approximately 45 kilometers parallel to the 64°50.00. meridian. Its width varies in between 1 and 4 kilometers and can be subdivided in a northern and southern tracts. The southern part has been already quite well studied with a complete description of its mylonitic rocks and the kinematic. Phyllonites in the northern tract and mylonites with phyllonites and non deformed rocks in the southern tract apparently separate two well defined domains of deformation. Two different deformation events, one ductile followed by a brittle stage, have been identified. We will present ductile textures developed in quartz veins included in strongly deformed granitic pegmatites which were intruded in the shear belt during the deformation. The data will be analyzed by regular texture analysis and viscoplastic self consitent simulations. The kinematic inferred from the simulations indicates a main reverse sense of displacement with a minor sinistral component developed in a simple shear regime.