Cu–Ni–Co–As (U) mineralization in the Anarak area of central Iran

Abstract

Cu–Ni–Co–As–U mineralization in the Anarak area of central Iran occurs at the intersection of the Uroumieh-Dokhtar magmatic belt with the Great Kavir–Doruneh fault. In the area, the volcanism associated with the magmatic belt is shoshonitic in character. Chemical analyses indicate that these are subduction related magmas. Detailed investigations in the vicinity of the Talmessi mine indicate that mineralization occurred in two separate stages: a first stage of copper sulphide mineralization with a relatively simple mineralogy and associated with the Eocene magmatism, and a second stage of Cu–Ni–Co–As–U mineralization with a complex mineralogy, which probably formed during another phase of deformation in the Upper Miocene. This later deformation reactivated previously formed faults. The mineralogy, element association and isotopic composition of carbonates for the second phase of mineralization suggest a different origin to that of the first phase. The fluids are likely to be non-magmatic in origin, possibly showing an increased input from meteoric waters. The close spatial association with basic/ultrabasic igneous rocks indicates that these may be the source through alteration and remobilization. The arsenide mineralization in the Anarak area shows many features that are similar to those of the classic five-element deposits.