Studies of geology, petrology, economic geology and alteration zones in porphyry copper deposit of Dareh-zar (southwest of Kerman)

Porphyry copper deposit of Dareh-zar is located in the Tertiary magmatic zone of Urmieh-Dokhtar. The emplacement of porphyry stock of Dareh-zar occurred along the axis of an anticline, with a NW-SE trend. Host rocks consist of Eocene volcanic and volcano-clastic rocks. Lithological composition of Dareh-zar porphyry pluton is quartz-monzonite. It is cut by masses of diorite and granodiorite porphyry and related dykes. Due to the cutting of supergene mineralization zone by diorite and granodiorite dykes, they can be considered as post mineralization dykes. Granodiorite dykes are less altered in comparison with dioritic dykes so are the youngest intrusion in area. Action of reverse faults resulted in more sever erosion on hanging wall blocks and therefore potassic alteration zone appears in this part on the surface. The main portion of the propylitic alteration zone is located in the host rocks. Supergene zone is located as lenses in phyllic alteration zone. Dioritic dykes intruded simultaneously with Dareh-zar porphyry and are mineralized, therefore, they are affected by supergene processes but they don’t have considerable amounts of copper. Parent magma of Dareh-zar porphyry mass was high K calc-alkaline with a slight tendency toward shoshonite. The study of variation pattern of REE in this mass indicates poor relative differentiation from LREE to HREE [(La/ Yb)N =0.26-3.71]. Remarkable enrichment of LILE is observable in this pluton which indicates magmatic contamination with crustal rocks, therefore, this result proved with negative anomaly of Nb. This pluton located in an active continental margin and is related to evolved post collisional arcs.