Relationships of copper and gold mineralizations with magmatic pulses in the Khankandi and Useflu bodies, East of Ahar

The study area is located in the east of Ahar town in Eastern Azerbaijan Province and is part of the Ahar-Arasbaran Cenozoic magmatic belt of NW Iran. The geological units of the Eocene age are volcanic rocks with andesite, latite - andesite and basaltic andesite composition.Khankandi and Useflu Oligocene intrusive bodies intruded in the volcanic rocks and caused widespread alteration and copper and gold mineralization. The intrusive bodies include I type granite, grano-diorite, quartz monzonite, monzonite-monzodiorite and gabbro. Granite, granodiorite and quartz monzonite belong to calk-alkaline series, while monzonite- monzodiorite and gabbro belong to alkaline series. They are related to continental margin tectonic regime and generated at post collisional tectonic settings. Alkaline basic rocks postdate calk-alkaline acidic rocks and are barren. The low sulfidation epithermal Au veins occurred in the Eocene volcanic rocks and Useflu quartz monzonitic body. Also Au-bearing quartz veinlets with relatively widespread alteration zone occurred at the eastern side of the Useflu intrusive body. Argillic and sericitic alteration accompanied the Au mineralizations. Pyrite, sphalerite, galena, chalcopyrite and bornite are the common ore minerals and occurred as disseminated and open space fillings. Stockwork and disseminated Cu mineralization occurred in the quartz monzonitic rocks at the SW side of Khankandi intrusive body. Pyrite, chalcopyrite, bornite with minor amounts of magnetite are the common ore minerals. Phyllic - pottasic alterations accompanied the Cu mineralization. Similar mineralizations of Cu occurred in other parts of the area (for example around the Useflu) in quartz monzonitic rocks which are accompanied by magnetite- mafic (amphibole and biotite) mineral veinlets.