Distribution and provenance of heavy metals in sand sediments of the rivers flowing in surrounding of the Dashkasan gold mine, northeast of the Qorveh city

In this research, the role of lithology and mineralization in the abundance of naturally occurring heavy metals in sand sediments of the rivers flowing surrounding the Dashkasan gold mine located in the northeast of the Qorveh city was evaluated. For this purpose, 30 samples were taken from 20 cm deep underground surface. The concentration of Fe, Ba, Zn, Cr, Pb, Cu, Co, As, Sb and Cd was measured in the medium sand size sediments and surface/groundwater samples. Thin/polish sections were prepared from the heavy mineral content of the sediments. According to results of the study, the amount of opaque heavy minerals is positively correlated with the concentration of Ba, Pb, Zn, As, Sb, Fe and Cd. Feldspar shows significant positive correlation with As and Ba. The volcanic rock fragments are correlated with Pb, Zn, Sb, Ba, As and Fe. There is positive correlation between the metamorphic rock fragment content of the sediments and Cr concenttration. Hornblende and biotite show relatively low positive correlation with Co, Cd and Ba. Sb, As, Pb and Ba have extremely high enrichment in the sediments, Cd is slightly enriched and other elements are depleted. According to the Point Load Index (PLI), most samples are classified as polluted. Based on the Igeo index, As and Sb fall into highly to extremely polluted classes and Cu, Co, Cr, Zn, Fe, Pb, Cd and Ba place between the unpolluted to slightly polluted classes.