Geostatistical-based geophysical model of electrical resistivity and chargeability data applied to image copper mineralization in the Ghalandar deposit, Iran

Document Type : Research Paper


1 Simulation and Data Processing Lab, School of Mining Engineering, College of Engineering, University of Tehran, Tehran, Iran

2 School of Mining Engineering, College of Engineering, University of Tehran, Tehran, Iran


This research aims to construct 3D geophysical models of electrical resistivity and induced polarization by interpolating 2D inverted physical models through the geostatistical approach. The applicability of the method was examined for the Ghalandar porphyry-skarn copper deposit in the Agh-Daragh region, northwest of Iran. The 3D geophysical properties and block models of Cu grades were prepared by implementing the kriging interpolation method, whereby the recovered electrical models were closely linked to the Cu-sulfide mineralization. In order to evaluate the efficiency of the applied technique, the variogram models were validated using a cross-validation analysis of the kriging operation, proving the accuracy of data interpolation for each model. For the sake of meaningful correlation between geophysical models and Cu grades, the mineralization zones were extracted and subsequently propagated in the 3D space according to the generated physical properties. Meanwhile, the evaluation matrix was utilized to assess the performance of acquired results, where it confirmed that simultaneous consideration of physical models could much better determine the location of the copper mineralization. Also, the Swath plot was used as a second validation way to compare the anomalous zones.


[1] Sun, J., & Li, Y. (2014). Exploration of a sulfide deposit using joint inversion of magnetic and induced polarization data. In SEG Technical Program Expanded Abstracts 2014 (pp. 1780- 1784). Society of Exploration Geophysicists.
[2] Telford, W. M., Geldart, L. P., Sheriff, R. E. (1990). Applied geophysics (Vol. 1). Cambridge university press.
[3] Oldenburg, D. W., Li, Y., & Ellis, R. G. (1997). Inversion of geophysical data over a copper gold porphyry deposit: a case history for Mt. Milligan. Geophysics, 62(5), 1419-1431.
[4] Mostafaei, K., & Ramazi, H. R. (2018). 3D model construction of induced polarization and resistivity data with quantifying uncertainties using geostatistical methods and drilling (Case study: Madan Bozorg, Iran). Journal of Mining and Environment, 9(4), 857-872.
[5] Irvine, R. J., & Smith, M. J. (1990). Geophysical exploration for epithermal gold deposits. Journal of Geochemical exploration, 36(1-3), 375-412.
[6] Allis, R. G. (1990). Geophysical anomalies over epithermal systems. Journal of Geochemical Exploration, 36(1-3), 339- 374.
[7] Bakkali, S. (2006). A resistivity survey of phosphate deposits containing hardpan pockets in Oulad Abdoun, Morocco. Geofísica internacional, 45(1), 73-82.
[8] Locke, C. A., Johnson, S. A., Cassidy, J., & Mauk, J. L. (1999). Geophysical exploration of the Puhipuhi epithermal area, Northland, New Zealand. Journal of Geochemical Exploration, 65(2), 91-109.
[9] Moreira, C. A., Rezende Borges, M., Vieira, L., Matheus, G., Malagutti Filho, W., & Fernándes Montanheiro, M. A. (2014). Geological and geophysical data integration for delimitation of mineralized areas in a supergene manganese deposits. Geofísica internacional, 53(2), 199-210.
[10] Vieira, L. B., Moreira, C. A., Côrtes, A. R., & Luvizotto, G. L. (2016). Geophysical modeling of the manganese deposit for Induced Polarization method in Itapira (Brazil). Geofísica internacional, 55(2), 107-117.
[11] Pelton, W. H., Ward, S. H., Hallof, P. G., Sill, W. R., & Nelson, P. H. (1978). Mineral discrimination and removal of inductive coupling with multifrequency IP. Geophysics, 43(3), 588-609.
[12] Vanhala, H., & Peltoniemi, M. (1992). Spectral IP studies of Finnish ore prospects. Geophysics, 57(12), 1545-1555.
[13] Thoman, M. W., Zonge, K. L., & Liu, D. (1998). Geophysical case history of North Silver Bell, Pima County, Arizona—a supergene-enriched porphyry copper deposit. Northwest Mining Association, 42.
[14] John, D. A., Ayuso, R. A., Barton, M. D., Blakely, R. J., Bodnar, R. J., Dilles, J. H., ... & Seal, R. R. (2010). Porphyry copper deposit model, chap. B of Mineral deposit models for resource assessment. US Geological Survey Scientific Investigations Report, 2010, 1-169.
[15] Sinclair, W. D. (2007). Porphyry deposits. Mineral deposits of Canada: A synthesis of major deposit-types, district metallogeny, the evolution of geological provinces, and exploration methods: Geological Association of Canada, Mineral Deposits Division, Special Publication, 5, 223-243.
[16] Brant, A. A. (1966). Geophysics in the exploration for Arizona porphyry coppers. Geology of the porphyry copper deposits: southwestern North America. University of Arizona Press, Tucson, 87-110.
[17] Niederleithinger, E. (2015). 3G-Geophysical Methods Delivering Input to Geostatistical Methods for Geotechnical Site Characterization.
[18] Tang, H. (2005). Geostatistical integration of geophysical well bore and outcrop data for flow modeling of a deltaic reservoir analogue.
[19] Pendrel, J. V. (2013). Integrating geologic and geophysical data in geostatistical inversion: GeoConvention 2013: Integration.
[20] Bourges, M., Mari, J. L., & Jeannée, N. (2012). A practical review of geostatistical processing applied to geophysical data: methods and applications. Geophysical Prospecting, 60(3), 400-412. 160 S. Salarian et al. / Int. J. Min. & Geo-Eng. (IJMGE), 54-2 (2020) 153-165
[21] Ramazi, H., & Jalali, M. (2015). The contribution of geophysical inversion theory and geostatistical simulation to determine geoelectrical anomalies. Studia Geophysica et Geodaetica, 59(1), 97-112.
[22] Asghari, O., Sheikhmohammadi, S., Abedi, M., & Norouzi, G. H. (2016). Multivariate geostatistics based on a model of geoelectrical properties for copper grade estimation: a case study in Seridune, Iran. Bollettino di Geofisica Teorica ed Applicata, 57(1).
[23] Berberian, F., & Berberian, M. (1981). Tectono‐plutonic episodes in Iran. Zagros Hindu Kush Himalaya Geodynamic Evolution, 3, 5-32.
[24] StScklin, J. (1968). Structural history and tectonics of Iran. AAPG Bull, 52(7), 1229-58.
[25] Nouri, F., Azizi, H., Stern, R. J., Asahara, Y., Khodaparast, S., Madanipour, S., & Yamamoto, K. (2018). Zircon U-Pb dating, geochemistry, and evolution of the Late Eocene Saveh magmatic complex, central Iran: Partial melts of subcontinental lithospheric mantle and magmatic differentiation. Lithos, 314, 274-292.
[26] Berberian, M., & King, G. C. P. (1981). Towards a paleogeography and tectonic evolution of Iran. Canadian journal of earth sciences, 18(2), 210-265.
[27] Rezaei, S., Lotfi, M., Afzal, P., Jafari, M. R., Meigoony, M. S., & Khalajmasoumi, M. (2015). Investigation of copper and gold prospects using index overlay integration method and multifractal modeling in Saveh 1: 100,000 sheet, Central Iran. Gospodarka Surowcami Mineralnymi, 31(4), 51-74.
[28] Shahabpour, J. (2005). Tectonic evolution of the orogenic belt in the region located between Kerman and Neyriz. Journal of Asian Earth Sciences, 24(4), 405-417.
[29] Kazemi, K., Kananian, A., Xiao, Y., & Sarjoughian, F. (2018). Petrogenesis of Middle-Eocene granitoids and their Mafic microgranular enclaves in central Urmia-Dokhtar Magmatic Arc (Iran): Evidence for interaction between felsic and mafic magmas. Geoscience Frontiers.
[30] Richards, J. P., Wilkinson, D., & Ullrich, T. (2006). Geology of the Sari Gunay epithermal gold deposit, northwest Iran. Economic Geology, 101(8), 1455-1496.
[31] Asl, H. A., Mehrabi, B., & Fazel, E. T. (2017). Mineralogy, occurrence of mineralization and temperature-pressure conditions of the Agh-Daragh polymetallic deposit in the Ahar-Arasbaran metallogenic area. Journal of Economic Geology, 9(9), 1-23.
[32] Mehrabi, E., Masoudi, F., Jamali, H., Asgharzadeh, H. (2013). Petrography, alteration, and mineralization of Agh-Daragh region. 17th Conference of Iranian Geological Society. Tehran, Iran. (Published in Persian).
[33] Kazem Alilou, S. (2015). Application of Fuzzy decision making approach in 2D mineral potential mapping and its comparison with 3D magnetic geophysical presentation in Ghalandar Zone, West Azerbaijan province of Iran. MSc. Thesis in University of Tehran, 1113 p. (Published in Persian).
[34] Kazem Alilou, S., Abedi, M., Norouzi, GH., Dowlati, F. (2013). Application of magnetometry, special resistivity and induced polarization for exploration of iron and copper skarn deposits, a case study: Ghalandar, Ahar. 1st national conference of exploration engineering, University of Shahroud (Published in Persian).
[35] Loke, M. H. (2004). Tutorial: 2-D and 3-D electrical imaging surveys.
[36] Mostafaie, K., Ramazi, H., & Jalali, M. (2014). Application of Integrated Geophysical and Geostatistical Methods in Amiriyeh Site Classification. Geodynamics Research International Bulletin (GRIB), 2(2), 1-15.
[37] Deutsch, C. V. (2010). Display of cross validation/jackknife results. Centre for Computational Geostatistics Annual Report, 12(406), 1-4.
[38] Ertunç, G., Tercan, A. E., Hindistan, M. A., Ünver, B., Ünal, S., Atalay, F., & Kıllıoğlu, S. Y. (2013). Geostatistical estimation of coal quality variables by using covariance matching constrained kriging. International Journal of Coal Geology, 112, 14-25.