Kahang copper porphyry deposit is located in Uromiye – Dokhtar volcanic belt, in Isfahan province. Kahang alteration system was identified by processing Landsat TM data in 2004. On the basis of hydrothermal alteration intensity, type and zonality of altered rocks in addition to surface mineralization (leached cap), geochemical signatures (Cu-Mo± Au anomaly), geophysical anomalies such as magnetic, induced polarization and resistivity Kahang is considered as a high potential porphyry deposit. After regional and preliminary exploration phases, detailed exploration was carried out at Kahang. The main objective of this research is 3D reserve estimation and modeling of the East Kahang deposit using available borehole data. A geochemical study was carried out on borehole assay data to investigate the subsurface downhole geochemical zonation and present erosion surface. In order to determine the zonality of elements, sample assay means in 50, 68, 80 and 100m composites were calculated first and then elements zonality series has been determined. In comparison with porphyry copper standard zonality sequences, the zonality of 80m composites including Co – Be – Ba – As – Mn – Pb – Zn – Sb – Cu – Ag – Mo – Bi were found to be present at Kahang. The geochemical ratio indices of As/Mo and (As.Mn)/(Cu.Mo) were found to be indicative of present erosion surface. In geophysical studies of the kahang area several IP/RS and magnetic profiles were utilized to identify the geophysical signatures associated with porphyry copper mineralizaton. In IP/RS studies profile number 112 was chosen for further processing and interpretation. This profile shows very good correlation between high chargeability and high resistivity in the northern part of the section. These signatures could be related to hydrothermal alteration associated with berrecia zones. Also 3D inverse modeling of IP/RS data shows similar signatures in the central part of deposit. Three dimensional inverse modeling of magnetic data suggests that the zone with high susceptibility in the northern part of the studied could be associated with strong magnetic mineralization.
