Gold Mineralization in Masjeddaghi Area

The Masjeddaghi area, located in the Jolfa 1/100000 geological map sheet, is a part of West Alborz zone - Azarbaijan. The oldest rock unit outcropped belongs to the Eocene flysh, widely distributed in the southern and north eastern part of the area. The other outcrops are mainly volcanic rock complex of andesite and trachyandesite affected by quartz monzonite intrusives and produced phyllic and carbonate phyllic alteration. The mineralization in volcanic complex is mainly silicic and barite veins. SEM and mineralography studies indicate the occurrence of sulphide mineralization especially Cu, Pb, and Zn sulphides. In addition, various pyrites occur as primary and secondary minerals. The galena and sphalerite mineralization can be observed in the main vein but not in the altrated area. SEM study indicates absence of gold in sulphide minerals. On the other hand fluid inclusion studies shows low temperature gold formation (120 - 150 °C) and very low salinity which specify probably that the gold is not carried along with chloridric complex in this stage. Evidences like parageneses, elements, gangue and alteration around silicified veins all indicate the presence of a polymetal gold - copper vein ore deposit of epithermal origin with high sulphide values.