Study of mineralization and fluid inclusions study in the Chenar-e-Olya iron skarn deposit, NW of Hamedan


Department of Geology,Lorestan Univercity, Khorramabad,Iran


      The Chenar-e-Olya iron deposit is located in Hamedan province and 24 km northern of Asadabad city. The deposit is located in terminal part of northwest of Sanandaj- Sirjan structural zone. Intrusion of Almougholagh quartz syenite mass in to the volcanic sedimentary rocks of Songhor series with Triassic- Jorasic age culminated in Chenar mineralization. Mineralization shows two structures namely massive and veins. Main ore forming mineral of Chenar deposit is magnetite.Hematite forms the second abundant ore mineral. Pyrite is the most aboundant sulfide phase. Fluid inclusions in quartz samples contain two phases resembling rich in liquid and elongating in shape. Microthermometry studies on fluid inclusions show that the average salinity and trapping temperature are respectively within 2.5-15.5wt%NaCl and 165-170 °C. Density of fluid in inclusions in quartz samples ranges between 0.89 to 1.02. Estimated depth of mineralization is 100 meters. The rate of pressure during the fluid formation approximated about 50 bars. Ore body at the Chenar experienced remobilization and metasomatism along shear zones, faulted boundaries and surface fractures. Geological observations combined with fluid inclusion studies including salinity, homogenization temperature indicate that the iron ore mineralization in the Chenar-e- Olya deposit occurred at the late stage of skarnization process.


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