The formation and evolution of Lak polymetal ore deposit based on fluid inclusion studies,, southwest of Boein Zahra,Qazvin province

Lak polymetal deposit is located in the 36 Km southwest of Boein Zahra, within the Oromieh - Dokhtar volcanic belt and western part of the central Iran zone. Based on field observations and petrogaphic studies, Eocene pyroclastic - volcanic rocks were the oldest outcrops in the studied area. A wide variety of volcanic rocks, volcano - sedimentary rocks, andesitic lavas, basaltic andesite, dacite, trachyandesite, tuffs and ignimbrites were distinguished in the study area. Mineralization is occurred in two forms: hydrothermal hypogene mineralization including galena, sphalerite, pyrite, chalcopyrite and magnetite, and supergene enrichment consist of cerussite, chalcocite, bornite and iron oxides and hydroxides (hematite and goethite). Major gangue minerals were comb structured quartz, barite and brecciated, banded, disseminated and colloform.Veins mineralization is accompanied with sericitic, argillic, kaolinitic, silicification and propylitic alteration zones which is mainly controlled by tectonic and hydrothermal processes. Fluid inclusions of polymetal Lak deposit are contained of liquid, gas and solid phases. Fluid inclusions of the study area were homogenized to liquid at temperatures between 160 and 280 °C. The inclusions gave salinities between 0.7 and 16.35 NaCl equivalent wt% and the evidences of temperature of homogenization (Th) and salinities of fluid inclusion given in this article shows that the study deposit is comparable with low sulfidation epithermal deposits.