Hamzelou Cu deposit: Redbed type sediment-hosted copper mineralization in the Upper Red Formation, NW Zanjan

The Hamzelou Cu deposit, 70 km northwest of Zanjan, is located in the Central Iranian zone. Copper mineralization in this deposit occurred in grey microconglomerate and sandstone units of the Upper Red Formation. Disseminated and cemented textures along with lens-shaped, solution seems, replacement, and framboidal pyrite are the main ore textures at Hamzelou deposit. The ore horizons contain red oxidized zone, bleached zone and mineralized reduced zone. Chalcocite and pyrite are the main ore minerals at the Hamzelou deposit. Malachite, azurite, covellite, atacamite, goethite and hematite are formed during supergene processes. Comparison of Chondrite normalized trace elements and REE patterns of barren red and grey host sandstones and mineralized samples indicate that mineralized samples show lower concentrations of trace elements and REE relative to host rocks. This signature indicate mobility of these elements during bleaching and mineralization processes. Based on tectonic setting, petrography, stratigraphy, mineralogy, ore structure and texture, and ore controlling factors (presence of plant fossils, salt domes, porosity and permeability of host rocks, faults and fractures), the Hamzelou deposit is a sediment-hosted Redbed type Cu deposit and is comparable with other Redbed type Cu deposits of the Mahneshan area. These deposits have close spatial relationship with evaporites and salt domes in the Upper Red Formation that must be investigated during exploration studies.