Hydrothermal evolution of the Sar-Kuh porphyry copper deposit, Kerman, Iran: A fluid inclusion and sulfur isotope investigation

Abstract

Sar-Kuh porphyry copper deposit is located 6 km southwest of the Sar-Cheshmeh copper mine, Kerman Province, Iran. Based on field geology, petrography and fluid inclusions studies, four alteration types have been identified in the Sar-Kuh area. Early hydrothermal alteration formed a potassic zone in the central parts of Mamzar granite/grano-diorite stock and propylitic alteration in its peripheral parts. The late hydrothermal activity caused a limited phyllic and argillic alteration zones. The mineralized quartz veins are classified into four groups, on the basis of mineralogy and cross-cutting relationships. Group I and II veins are concentrated mainly in the potassic alteration zone, while group III and IV are most abundant in the phyllic and propylitic alteration zones, respectively. Fluid inclusion studies on group I and II quartz veins show that potassic alteration has originated from a dominantly magmatic fluid with high salinity (30-50 wt % NaCl equiv) and temperature (>300oC). The ?34S values of separated pyrite and chalcopyrite from samples range between +1.29‰ to +4.72‰ (mean value of +2.68‰), consistent with a magmatic origin for sulfur.