The Sirjan mylonite nappe is part of the Sanandaj–Sirjan HP–LT Metamorphic Belt (Zagros Orogenic Belt, Iran). This nappe was emplaced in a transpressional regime during oblique convergence between the Afro–Arabian Continent and Central Iranian Microcontinent. In order to investigate the type of flow, fabrics from deformed quartz and K-feldspar porphyroclasts were analyzed. Quantitative fnite strain (RXZ = 1.9–3.8) and mean kinematic vorticity number (Wm = 0.60–0.85) analyses revealed that both the strain ratio and the simple shear component of deformation increase towards SE along a 2 km long NW–SE-oriented transect. Analysis of quartz and K-feldspar textures suggests shearing at c. 400–650 °C. We also conclude that deformation in the Sirjan mylonite nappe began with nearly pure shear flow but became a more simple-shear flow in character as strain accelerated.
کلید واژگان :kinematics, mylonite, vorticity, strain path, deformation, Zagros Orogenic Belt
ارزش ریالی : 600000 ریال
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