مقایسه کانسارCu-Ag-Au قلعه‌ زری با دیگر کانسارهای نوع Iron Oxides Cu-Au (IOCG) و ارائه رده‌بندی جدید

The Qaleh-Zari specularite- rich Cu-Au-Ag deposit is located 180 Km south of Birjand. Host rocks are mainly Tertiary andesites and andesitic basalts and some Jurassic shales and sandstones. Andesitic rocks from the western region of Qaleh-Zari were dated to 40.5±2 Ma. Four trends of faults and joints are identified in the mine area.  The oldest is mineralized. Three major sub-parallel quartz veins are present. No. 2 vein is the main vein and can be traced for more than 3.5 km along strike (N40°W) and more than 350 m down dip. Paragenesis: Stage I: specularite, quartz, Fe-chlorite, chalcopyrite and sulfosalts. Specularite deposited first and forms 10 to 25 percent of the vein. Ore grade is 2 to 9% Cu, Ag 100 to 650 ppm, and Au 0.5 to 35 ppm. Propylitic alteration is dominant and epidote is very abundant. Argillic alteration is locally present. Silicification is mainly found within the vein zone. Temperature of homogenization of primary fluid inclusions in quartz associated with specularite and Cu, Ag, and Au mineralization was between 240°C and 360°C. The salinity of ore fluid was between 1.0 and 6.0 wt% equiv. NaCl and the CO2 was < 0.1 mole%. Based on the presence of hematite, chalcopyrite, Fe-rich chlorite, and, locally pyrite, and on the absence of magnetite and pyrrhotite, the ore fluid was very oxidizing. Some important differences between Qaleh-Zari and other iron-Oxides Cu-Au deposits are: (1) The salinity is very low (< 6 wt% NaCl equiv.), (2) absence of magnetite and apatite, (3) low REE and P., and 4) high grade Cu, Ag, and Au. Differences in the amount of Cu, Au, REE, P, U, F and some other elementals in iron-oxides Cu-Au deposits are related to: Tectonic setting, depth of magmatism, source of magma, degree of partial melting, physicochemical condition of melting, rate of ascending, crystal assimilation, degree of fractionation, and depth of emplacement.