Geology, mineralogy and geochemistry of Ferezneh ferromanganese anomaly, east of Sangan mines complex, NE Iran

The Ferezneh prospect area is one of the eastern anomalies of Khaf’s Sangan iron mine. The Sangan mines complex is located within the Khaf-Kashmar-Bardeskan volcano-plutonic and metallogenic belt in northeastern Iran. The Sangan mine is the largest Fe skarn in western Asia، having a proven reserve of over 1000 Mt iron ore @ 53% Fe (Golmohammadi et al.، 2015) and consisting of three parts; western، central and eastern Sangan، each part including several anomalies. In this study، Ferezneh (North and West) prospect area which is an eastern anomaly of the Sangan iron ore is discussed. Ferezneh anomaly is located in 60°36''7 «- 60°34''27» E and 34°30''47 «- 34°29''46» N، 35 km south of the city of Taybad، 10 km southeast of Karat and 1. 5 km southwest of Ferezneh village. The purpose of this study was to prepare a geologic map for separation and identification of the intrusions، determining their relationships with mineralization، distinguishing the type of mineralization، mineralogy، petrology and geochemistry of the mineral deposits، and finally their relationship with other major Sangan’s deposits.

In order to achieve the objectives of the study: 1- 140 thin sections of the intrusive rocks، marble limestone and dolomite، as well as 40 polished sections of ore were taken in an area of 9. 5 km2. Mineralogy and mineralization studies were performed in the Economic Geology Laboratory of Ferdowsi University of Mashhad. 2- A few samples were selected for X-ray diffraction analysis in order to ensure accuracy of mineralogical studies and were sent to Binalood Laboratory in Tehran. 3- In addition to major and minor elements geochemistry study of the ores، 10 samples were sent to East Amitis Laboratory in Mashhad for XRF analysis and also to Canada S. G. S Laboratory for ICP-MS analysis. Discussion and

Mineralization in the Ferezneh prospect area was limited to iron and manganese oxides in the form of massive and stratabound in recrystallized limestone that followed the structure pattern. Iron oxides often include goethite and hematite; while manganese oxides are pyrolusite، psilomelane and lesser amounts of cryptomelane. Small spots of rutile are rarely seen. The gangue minerals are dolomite، calcite and cryptocrystalline quartz. XRD analysis shows that iron and manganese oxides are the only metallic minerals.