تحليل هندسي ميكاشيستهاي خاور باتوليت همدان

The geometrical analysis of micaschists in the east of Hamedan batholith

The study region covering 610 square kilometres is located in south-east of Hamedan in the northern part of the Sanandj-Sirjan belt. This region consists mainly of micaschists and slate with a nearly northwest - southeast trend. This complex (tectonites) is Pre-Jurassic, which during two phases has undergone plastic deformation and comprises chiefly S-L tectonites and in some parts S tectiontes. In the first phase, schistosity (S ) was formed Parallel to the sedimentary bedding with average strike and dip of N135156E and N138/30SW. Moreover, during this phase many kinds of lineations have resulted from microfold, mineral and pressure shadow. The wavelength of microfolds is a few millimetres and alternatively followed by one another with N188112 trend. Minerals which constitute the lineation are mica and amphibole. Staurolite and garnet porphyroblasts are pre to syn-tectonic. Also at this phase, intrafolial folds of quartz vein were farmed in between the first schistosity. The second phase of deformation was created following the lateral forces (with N56 trend) which constitutes the basic structure of the region. S 2 Plane in this phase was formed following S , flexural- slip folding which created axial plane of folds with N164/61NE and N154/64SW. Second lineation (L2 ) with arerage trend and plunge N157/07 is also the axles of these microfolds. Other lineations of this phase are intersected by andalusite lineations which are L 2 . Macrofolds are longitudinal type and located in succeeding anticlines and synclines with arerage axial plane of N148/74SW parallel to L 2 . Muscovite and quartz subfabric elements are oriented in this phase and like S , S 2 and L 2 fabric elements have orthorombic symmetry.