Investigations about lithology, geochemical composition and alteration of gold deposits in Kooh-e Zar Damghan and the process of gold mineralization in this area

Abstract

Detailed field investigation with geochemical, petrogenetic and alteration studies have been carried out in a large area, measuring 300 hectares, in gold deposits of Kooh-e Zar to determine the anomaly points and intrinsic geological unites (IGU) which will lead us from reconnaissance to exploration phases in the region.In this regard, about 600 geochemical samples were taken from different geological unites and analyzed by XRF and atomic absorption (AAbs) methods. Atomic absorption was used to detect Au element, and 30 others elements were analyzed by XRF method. The data can be used for further statistical analysis. The results showed that the observed outcrops in the region are mainly volcanic rocks, which are a combination of dacite, thrachyte, hrachyandesite, andesite and intrusive rocks, which are granitoid in combinations (granodiorite, monzonite, quartzmonzonite, syenite and quartzsyenite). Having reviewed the findings, it becomes clear that the source magma of the region is of calcalkaline type, and granitoid in Baghoo is of CAG type. Argilitic, silicific, potassic, sericitic and prophylitic alterations were effective in Baghoo and have direct connection with mineralization. Tourmaline and pyrite alterations exist locally. For geochemical results, existing data were statistically studied, variograms of all elements were depicted for the determination of deposit variability. Anomaly prospects of all variables were done by statistical calculations. Their analysis introduces following districts indicate further deposits: south of Pazo (Pazo Anomaly), quartz vein containing gold (Amooei anomaly) and near Khani adits (Khani Anomaly).