Crustal lineament control on mineralization in the Anarak area of Central Iran

The Anarak mining area in Iran is identified as one of the best known examples of mineralization located at the intersection of two important crustal-scale lineaments, which are the E_W striking Great Kavir fault and the NW–SE trending Urumieh-Dokhtar Magmatic Belt. The objective of this research is to investigate the role of the lineaments and their subsidiaries at Anarak area in the genesis of mineral deposits. Lineaments are long-lived features which control or affect ancient as well as young crustal sequences. Lineaments are also deep-seated, because they commonly control the emplacement of deep crustal or mantle-derived magmas. Metallogenic areas of up to ~ 1000 km2 might be observed in areas where broad structural zones intersect, because they can facilitate the localization of magmatic or hydrothermal centers. The two lineaments that intersect in the Anarak area were both very active during mineralization. Therefore, it is likely that pull-apart basins or other dilatational sites at the intersection point were not preserved for substantial lengths of time, and single large magma conduits would have been divided into smaller conduits for magma penetration and hydrothermal circulation. The presence of these small conduits in addition to a small magma input could produce conditions for the circulation of mainly meteoric waters, in which the magmatism has acted as a heat source for the mineralization system. This phenomenon has led to the generation of a metallogenic area with several similar small deposits within a circular area of radius ~ 30 km centered at the intersection point. The two most famous deposits in this area are Talmessi and Meskani in which mineralization had occurred in two separate stages: first stage — fissure-filling copper sulfide mineralization associated with Eocene magmatism (veins, veinlets, and stockworks). The second is an overprinting stage which occurred after a fairly long interval which involves the formation of Ni–Co arsenides and U oxide minerals.