Mashhadi S.R., Nikfarjam M. & Mehrnia A.K., 2020: Reinterpretation of resistivity and induced polarization data to explore gold mineralization zones at Zarzima prospect, Iran. Acta Geologica Slovaca, 12, 1, 15–22.

Reinterpretation of resistivity and induced polarization data to explore gold mineralization zones at Zarzima prospect, Iran

Seyyed Reza Mashhadi¹, Meysam Nikfarjam¹ & Ahmad Kazemi Mehrnia²

¹Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), 424 Hafez Ave, 15875-4413 Tehran, Islamic Republic of Iran; reza.mashhadi93@aut.ac.ir, reza.mashhadi93@yahoo.com
²Parsi Kan Kav Engineering Consultant Company, Eastern Arash Blvd, Farid Afshar St., Shariati Ave. 8, 19198-65956 Tehran, Iran

Abstract

Zarzima is a gold prospect located in the west of Muchesh city, Kurdistan province, Iran. According to the geological studies, gold mineralization mainly occurs within silicified alteration zones / quartz veins and veinlets. Some silicified veins have been mapped in the 1:1,000 geological map of the area. To improve the results of drillings, resistivity and induced polarization tomography surveys were performed before the exploration drillings in the study area. As the geophysical models didn’t really coincide with the geological information, we have decided to reprocess and reinterpret the previously recorded geophysical data with further theoretical considerations. Interesting results yielded with suitable inversion criteria and precise data processing. This investigation indicated that high resistivity anomalies represent silicified alteration zones. In fact, some branch-like high resistivity features are detected which is consistent with the hydrothermal mineralization systems. The fault zone is also characterized precisely in the resistivity and IP models. Note that previous analysis of geophysical data neglected the most important anomalous zone in the study area. The previous analysis also didn’t reveal the branch-like structures and the fault zone. These facts clearly show the importance of suitable selection of inversion parameters and also avoiding the use of large “n” values in the dipole-dipole array.

Key words: Gold Exploration, Resistivity, Induced Polarization (IP), Silicified Alteration, Zarzima, Iran

Manuscript received: 2019-07-29

Revised version accepted: 2020-04-07