Refference : The 25th Symposium on Geoscience;Tehran
Publishing Year : 1385

Abstract :
The metamorphic rocks in the field show two phases of ductile deformation and were later affected by ductile-brittle and brittle deformations. Structural elements of the first deformation phase are: an axial plane foliation, mineral lineation and rootless similar folds. Structural elements of the second deformation phase include stretching lineation, mylonitic foliation, similar and sheath folds. Also boudins and ductile shear zones are formed in this phase. Parallelism of lineation and the fold axial planes of the first and second generations, shows that they are formed in a progressive deformation phase. The third and fourth phases are accompanied with retrogression of metamorphic and deformation conditions. The structures of the third deformation phases include crenulation folds and crenulation cleavage. Chevron folds and thrust faults are formed in fourth phase of deformation. Separation of the different generations of folding accomplished based on properties such as: folding of bedding plans in relation with foliation, folding of the foliation planes and forming crenulation cleavage and studying of the metamorphic conditions (petrofabric studies).
Subject List : Deformation