Fe-mineralization in the East-anomaly of Sangan deposit NE of Iran
Subject Areas :Mohammad Yazdi 1 , مهرداد Behzadi 2 , Mahdi Haji-Ali 3
1 - دانشیار دانشکده علوم زمین،دانشگاه شهید بهشتی
2 - استادیار دانشکده علوم زمین،دانشگاه شهید بهشتی
3 - دانشجوی کارشناسی ارشد زمینشناسی اقتصادی، دانشکده علوم زمین، دانشگاه شهید بهشتی
Keywords: Skarn and hydrothermal Fe- mineralization, Eastern anomaly, Sangan ore deposit,
Abstract :
The Sangan iron deposit is composed of Western, Central and Eastern anomaly. The Eastern anomaly,contrary to those two other anomalies, is composed of several scattered mineralization outcrops withlow total reserve. Sarnowsar is the main intrusive body that has been intruded in to the north ofEastern anomaly of Sangan iron deposit. It has monzogranitic composition. Mineralogical andchemical properties of this monzogranite is I-type, calk-alkaline with high K. It belongs to magmaticcontinental arc setting and subduction zones. The Fe mineralization in this area is related to EoceneOligocene magmatism and its magmatic and hydrothermal fluids.In the Eastern Anomaly, two types of mineralization were distinguished: 1- the magnetite skarnmineralization (high temperature) in the contact of granite and limestone or dolomitic limestone, 2-wellastonite, chlorite, hematite and goethite hydrothermal mineralization (low temperature) with orwithout barite mineralization within dolomitic limestone, calcareous sandstone and acidic volcanicrocks. In the first type, magnetite with minor pyrite and chalcopyrite as well as gangue minerals suchas forsterite, garnet, clinopyroxene, tremolite-actinolite, scapolite, phlogopite, epidote, chlorite, quartzand carbonate have been observed in the forms of massive, lens-like (parallel with limestone layers),lamination and vein-type. In the second type, mineralization has been occurred in the form of irregularmassive (centimeters to meters), replacement, disseminated, void and breccias matrix filling, vein,veinlet and stockwork, depending on the wall rock type and area structures. They are accompaniedwith alterations such as dolomitization, silicification, sericitization, carbonatization and rarelytoumalinization.
