Application of mineral chemistry to mineralization and alteration evaluation in Zn-Pb Angouran deposit, Zanjan

Angouran zinc and lead deposit is located about 135 km west of Zanjan city, in the northwest of the Sanandaj-Sirjan structural zone The results of this study indicate that the dolomitic alteration occurred in the carbonate hanging-wall and the presence of ankerite in the schist footwall. The main host of ore deposit is metamorphic carbonate. The Angouran dolomite is secondary and hydrothermal. Formation of secondary porosity in dolomite provided the required space for the formation of sulfide ores including sphalerite, galena and pyrite, in the carbonate host rock. We found out that sphalerite of Angouran is rich in iron, cadmium and germanium, and the galena is rich in antimony and silver. The geothermometry of Angouran sphalerite indicates that the mineralization temperature ranges between 170-190º C. Comparing these characteristics with other lead and zinc deposits, it is concluded that Angouran deposit is most similar to Mississippi Valley Type (MVT) deposits, and mineral chemistry and formation temperature are fundamentally different from other types of mineralization.