The study of garnet formation in the migmatite rocks, Hamadan area

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Research Paper 01/09/2014
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The study of garnet formation in the migmatite rocks, Hamadan area

Hoseeinmirzaee Zahra, Dadkhah Rasool
J. Bio. Env. Sci.5( 3), 392-398, September 2014.
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The study area is located in the south-southeast of Hamedan in the Sanandaj-Sirjan zone that comprising low to high grade regional (orogenic) and thermal (contact) metamorphic rocks. Intruded by mafic, intermediate and felsic plutonic bodies. Hamadan metamorphic rocks can be divided in three groups: regional metamorphic, contact metamorphic and migmatites. migmatites division in two groups: silimanite migmatite and cordirite migmatite. Garnet crystals are common pyralespite (almandine) type and this mineral recognize in leucosome, melanosome and mesosome parts. Garnet crystals in the leucosome of migmatites have igneous and metamorphic origin. In the first case, the garnet crystals was euhedral, sustainable in leucosome of migmatites and are not transformation from around to other minerals. These garnets crystallize of melt from partial melting and have igneous origin. In the second case, the garnet crystals was subhedral to anhedraland are not stable in leucosome of migmatites. These garnets are transformation and reaction from around to other minerals. These crystals have metamorphic origin and possibly remnants of mesosome garnet that residue in melt from partial melting and not melting. According to the reaction garnet formed between 550-650 C̊ temepture.


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