Cu mineralization and geochemical haloes characteristics of Garmab district (eastern Semnan)


Department of Geology, Faculty of Sciences, University of Isfahan, Isfahan, Iran


The Garmab Cu mineralization, in the east of Semnan and southeast of Shahroud, is situated in the Eocene conglomerate association with weakly hydrothermal altered. The weak alteration, mineralization and geochemical haloes is locally controlled by faults and late fractures. At the surface, secondary copper minerals including malachite and azurite and in the depth, primary sulfides generally are pyrite, arsenopyrite and chalcopyrite. Gangue minerals of the veins are commonly quartz, chalcedony, opal and minor calcite. Other components contain goethite, limonite and hematite with manganese oxides and minor jarosite smithsonite and gypsum. The results of statistical geochemical analyses indicate a positive correlation between copper with Au, Ag and As. According to host rock, mineralization, spatial relationships and geochemical dispersion patterns, deep drilling is suggested in the depth in the east of mineralization. The study district is related to buried intrusive bodies and epithermal vein-type Cu deposits.