Study of the formation of industrial garnets in garnet micaschists south of Alvand, Hamadan, Iran

Document Type : Original Article

Authors

Department of Geology, Faculty of Science, Bu-Ali Sina University of Hamadan, Hamedan, Iran

Abstract

The Jokar region is located in the southeast of Hamedan province in the Sanandaj-Sirjan zone. The rock unit of the region includes garnet schist and phyllite rock units. Quartz, biotite, muscovite and garnet were observed in microscopic examination. Garnets have two generations including garnets before and during tectonic activity and garnets during tectonic activity. EPMA analysis showed that the zoning of garnets is almandine, grossular, spessartine and andradite. Garnets have no physical zoning but have chemical zoning. Mn and Ca elements decrease from the center to the crystal edge and Fe increases. Five types of intercalation (L), (V), (L+V), (L+V+S) and (L+V+S1+S2) have been observed. The homogenization temperature of the inclusions in the samples is between 322 and 485 oC. Also, the salinity values ​​of the inclusions were found to be between 5.7 and 19.6% by weight equivalent to table salt. The density of the fluid forming garnets is between 0.569 and 0.842 g/cm3. The fluid forming garnets has a magmatic and metamorphic origin.Keywords: Micaschist garnet, chemical zoning of garnet, magmatic metamorphic origin.

Keywords


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