Document Type : Original Research Paper
Authors
1 M.Sc., Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran
2 Assistant Professor, Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran
3 Associate Professor, Islamic Azad Unuversity, Islamshahr Branch, Tehran, Iran
Abstract
Based on Qayen 1:100000 geological map, the copper mineralization of Vorezg in volcanic rocks is attributed to Paleocene-Lower Eocene. Submarine volcanic rocks of the study area are found in two forms of lava and pyroclastics. Based on field and laboratory investigations, the outcropped rocks in Vorezg deposit are andesite, andesite – basalt, basalt and several small exposures of pyroclastic rocks such as tuff. Alkaline volcanic rocks of the area show within plate characteristics. Texture of mineralization is vein-veinlet, disseminated and open space filling amygdales. According to the mineralography studies, main minerals of copper are chalcocite, β-chalcocite, bornite, covellite, digenite and rare native copper. Chalcocite is the most abundant mineral. Intergrowth among copper ores is observed in most cases. Silver was detected as accessory phase (copper element paragenesis) in this ore deposit. Whereas silver has not founded an independent crystalline phase, therefore in the crystal of chalcocite, copper was replaced by Ag. Fluid inclusion studies on trapped fluids in quartz show homogenization temperature average is 230-250 ºC and salinity degree of fluids is 5-6%wt NaCl. On the basis of recognized characteristics, Vorezg ore deposit is comparable with Manto and Volcanic redbed type copper deposits. Recently, these two types of deposits are considered as synonyms.
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