Discriminación de mecanismos de deformación dominantes en las calizas miloníticas del Zilair Thrust (Sur de Urales), mediante el análisis de paleoesfuerzos

Abstract

The calcíte mylonites at the base of the southern Urals accretionary prism presenta high density of mechanical twins and dynamical recrystallized grains. Grain size and shape analysis of sorne calcmylonites were used to estímate pa/aeostress values, which are ranging between 135 and 229 MPa. Since pa/aeostress based on recristallized grain size are /ower than pa/aeostress obtained previovsly by twin density (230±40 MPa), the methods constrains are discussed and resvlts are interpreted in accordance with the domain of different ca/cite mechanisms during deformal'ion. Bot/-i results are consistent With the hypothesis that the recrystallized grains sizes are limited by the twinning field boundary in the deformatíon mechanism map.