Delineating mineralized phases based on lithogeochemical data using multifractal model in Touzlar epithermal Au–Ag (Cu) deposit, NW Iran

The aim of this study is to delineate and separate mineralization phases based on surface lithogeochemical Au, Ag, As and Cu data, using the Concentration–Area (C–A) fractal method in the Touzlar epithermal Au–Ag (Cu) deposit, NW Iran. Four mineralization phases delineated by multifractal modeling for these elements are correlated with the findings of mineralization phases from geological studies. The extreme phase of Au mineralization is higher than 3.38 ppm, which is correlated with the main sulfidation phase, whereas Ag extreme phase (higher than 52.48 ppm) is associated with silicic veins and veinlets. The resulting multifractal modeling illustrates that Au and Ag have two different mineralization trends in this area. Extreme (higher than 398.1 ppm) and high mineralization phases of Cu from the C–A method correlate with hydrothermal breccias and main sulfidation stage in the deposit, respectively. Different stages of Au mineralization have relationships with As enrichment, especially in high and extreme (higher than 7.9%) phases. The obtained results were compared with fault distribution patterns, showing a positive correlation between mineralization phases and the faults present in the deposit. Moreover, mineralization phases of these elements demonstrate a good correlation with silicification and silicic veins and veinlets.