Geology, mineralogy and genesis of stratiform Cu mineralization in the Tazeh-Kand area, Northeast of Tabriz

Tazeh-Kand Cu mineralization area is located in ~20 km northeast of Tabriz, eastern Azarbaijan province. The area is a part of Central Iranian geo-structural zone in the eastern margin of the Tabriz 1:100000 geological map. Lithological units in this area composed of green- grey sandstones (redox zone), red sandstones and marl (oxidized zone), salt domes and conglomerate (Miocene) along with dacitic domes (Pliocene). Based on petrographical investigations, the host sandstones are sub- mature to immature lithic arkos and were deposited in a tidal environment. Cu mineralization in this area occurred as stratiform type within the redoxed sandstones. The thickness of mineralized horizons vary between 30cm to 1m which are crops out up to 500m in some horizons. Concentration of Cu mineralization has direct relation with organic matter concentration. Mineralized horizons composed of three zones include: mineralized redox zone, bleached zone and red oxidized zone. Mineralogical investigations show that this mineralization composed of primary sulfide minerals include pyrite, chalcocite and digenite along with supergene minerals include covellite, malachite and Fe- hydroxides. Texturally, these minerals present as lenticular, disseminated, replacement, inter- grain cement and solution seems textures. According to petrographical and mineralogical results such as pyrite and primary chalcocite bearing redox sandstone, structural and textural evidences, stratigraphy, mineralization controlling factors, presence of organic matter as a redox material, permeability of host rock and salt diapirism, mineralization in the Tazeh-Kand area is mostly similar to RedBed type mineralization which is formed during the early to late diagenesis.