Oriented growth and deformation aluminum silicates in metamorphic rocks of Hamedan

Andalusite shows at least two oriented growth phase in regional and contact metamorphic rocks of Hamadan. in regional metamorphic rocks Andalusite are oriented along South East trend and in metamorphic these are orinted along North-East trend. Syn-tectonic Andalusite porphyroblast has been Boudined affected by layer parallel extension and even formed interesting structure (for example porphyroclast) by non coaxial deformation in this part. In Hamadan metamorphic rocks that are near the Alvand granitoid, an appropriate sites for nucleation of sillimanite is highly variable. One of nucleation sites is growth of sillimanite within the andalusite porphyroblast. Sillimanite, often formed within the twining and along crystal fractures in the andalusite. Some of the sillimanite are defromed and folded. Deformed sillimanite show effect of non-coaxial deformation in this area. Formed sillimanite within the andalusite indicate deformation at elevated temperatures in this area and Even after the formation of sillimanite, tectonic forces have been presence and caused their deformation in this region.