Copper mass flux and evolution of supergene orebody in the Miduk Porphyry Copper Deposit, Iran, and its application to exploration of exotic deposits

Abstract

The present study used field geology and aimed to model the geological results by modern methods for examining the effects of geological features on the formation of an enriched ore in a mature supergene profile such as Miduk Porphyry Copper Deposit (MPCD). In addition, it aimed to discover which geologic controllers caused the fixation or conduction of Cu in supergene solutions. To this end, the anatomy of the supergene zones was examined by direct sampling and mapping. Analysis of fracture density helps uncover the role of fractures in conveyance of fluids. The results showed that MPCD endured a systematic supergene process, which resulted in the formation of a 200-meter enriched orebody on the top of the hypogene ore. Additionally, the topographic gradient was the most important controller in the migration of supergene solutions to northern side while the north–south trending fractures doubled the lateral flux. Furthermore, the mass balance analysis indicated that 181,000 tons of Cu laterally escaped from the supergene system. Considering the geochemical conditions in sources areas, this amount of metal was sufficient to form a proximal type of exotic mineralization. Further, drainages derived from the main deposit exhibited exotic mineralization, which supported the lateral movement of Cu from the main orebody.