Analysis of the relationship between mineralization and alteration zones with tectonic structures using remote sensing studies in south Ardestan area (northeastern Isfahan)

The study area is located in central part of the Urumieh-Dokhtar magmatic arc and the southeast Ardestan area. Eocene volcanic rocks units with a combination of andesite and basaltic andesite constitute the most extensive rock units in the study area. These units are host to Ag-Cu and Au mineralization and alteration zones. Utilization of remote sensing methods especially composite pseudo color and Filters helped us to obtain valuable information on alteration zones, existing brittle structures and the role of Zafarghand fault in controlling alteration zone. The distribution pattern of the faults on processed satellite images, shows three generally orientations, changing in fault orientations, the density of faults in the north of the area and positive flower structure. Two different patterns of alteration zones are observed including propylitic alteration and zones of secondary iron oxides with large distributions around copper veins and argillic-sericitic alteration zones with limited and linear distributions around quartz veins. Comparison of the pattern of faults, mineralization and alteration zones indicate a decrease in the degree of mineralization and increase the extent of alterations along with reducing the density of faults from north to south of the region. The Zafarghand fault has an effective role in the creation and development of alteration in the study area. In this way, alteration is only seen toward the northern parts of this fault. The flower structure has created a tenstion and suitable location for mineralization and confluence of alteration zone in the south of the area.