Application of an improved zonality index model integrated with multivariate fractal analysis: epithermal gold deposits

Document Type : Research Paper


1 Department of Geology, Payame Noor University, PO Box 19395-3697, Tehran, Iran

2 Department of Petroleum and Mining Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran

3 Iranian Society of Mining Engineering, Tehran, Iran

4 Geology Society of Iran, Tehran, Iran

5 Department of Economic Geology, Tarbiat Modares University, Tehran, Iran

6 EarthByte Group, School of Geosciences, University of Sydney, NSW 2006, Australia

7 Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW 2052, Australia


The main goal of this present study is to apply an improved zonality index to epithermal gold ores based on staged factor and number-size (N-S) fractal analysis. This technique was utilized in Bardaskan district, NE Iran, which is epithermal gold mineralization. An improved zonality index is a proportion of factors including ore and pathfinder elements based on rock samples. Consequently, two factors were selected after four stages of the staged factor analysis which consist on F-4 (As-Fe-Mo-S) and F 3-4 (Au-Ag). Based on these factors, (F1-4)/(F3-4) is determined as an improved zonality index. In addition, the improved zonality index was categorized by fractal modeling. The N-S model demonstrates that the major anomalies of this improved zonality index are associated with silicification as main alteration zone and the intersections of faults, particularly in the NE and northern parts of the Bardaskan region. Additionally, additional rock samples with Au higher than 100 ppb are located in anomalous parts of the improved zonality index and marginal parts of this area with high values of this index contain pathfinders of gold mineralization, especially As based on this methodology. This methodology could be strongly considered in the exploration of different types of mineral deposits and the classification of the target anomalies.


Main Subjects

Article Title [Persian]


Abbasnia, H., Karimpour, M.H., Malekzadeh Shafaroudi, A., 2019. Damanghor intermediate sulfidation epithermal Au mineralization, Northern Bardaskan: geology, alteration, mineralization, and geochemistry. Iranian Journal of Crystallography and Mineralogy. 27(3): 621-634 (In Persian with Geopersia 2022, 12(2): 379-394 391##
Adib, A., Nabilou, M., Afzal, P., 2021. Relationship between Fe-Cu-REEs mineralization and magnetic basement faults using multifractal modeling in Tarom region, NW Iran. Episodes.
Afzal, P., Eskandarnejad Tehrani, M., Ghaderi, M., Hosseini, M.R., 2016. Delineation of supergene enrichment, hypogene and oxidation zones utilizing staged factor analysis and fractal modeling in Takht-e-Gonbad porphyry deposit, SE Iran. Journal of Geochemical Exploration. 161: 119-127.##
Afzal, P., Yousefi, M., Mirzaei, M., Ghadiri-Sufi, E., Ghasemzadeh, S., Daneshvar Saein, L., 2019. Delineation of podiform-type chromite mineralization using Geochemical Mineralization Prospectivity Index (GMPI) and staged factor analysis in Balvard area (southern Iran). Journal of Mining and Environment. 10: 705-715.##
Afzal, P., Fadakar Alghalandis, Y., Khakzad, A., Moarefvand, P., Rashidnejad Omran, N., 2011. Delineation of mineralization zones in porphyry Cu deposits by fractal concentration-volume modeling, Journal of Geochemical Exploration. 108: 220-232.##
Afzal, P., Heidari, S.M., Ghaderi, M., Yasrebi, A.B., 2017. Determination of mineralization stages using correlation between geochemical fractal modeling and geological data in Arabshah sedimentary rock-hosted epithermal gold deposit, NW Iran. Ore Geology Reviews 91: 278-295.##
Afzal, P., Zia Zarifi, A., Sadeghi, B., 2014. Delineation of geochemical anomalies using factor analysis and concentration-number (C-N) fractal modeling based on stream sediments data in Esfordi 1:100000 sheet, Central Iran. Iranian Journal of Earth Sciences. 5: 100-110.##
Agterberg, F.P., 1995. Multifractal modeling of the sizes and grades of giant and supergiant deposits. International Geology Review. 37: 1-8.##
Alavi, M., 1994. Tectonics of Zagros Orogenic belt of Iran, new data and interpretation. Tectonophysics. 229: 211 -238.##
Aliyari, F., Afzal, P., Lotfi, M., Shokri, S., Feizi, H., 2020. Delineation of geochemical haloes using the improved zonality index using multivariate and fractal analysis in the Cu-Mo porphyry deposits. Applied Geochemistry. 121, 104694.##
Beus, A.A., Grigoryan, S.V., 1977. Geochemical Exploration Methods for Mineral Deposits. Applied Publishing Ltd., Wilmette, Illinois.##
Beyranvand, D.P., Arian, M.A., Farhadinejad, T., Ashja Ardalan, A., 2021. Identification of Geochemical Distribution of REEs Using Factor Analysis and Concentration-Number (C-N) Fractal Modeling in Granitoids, South of Varcheh 1:100000 Sheet, Central Iran. Iranian Journal of Earth Sciences. 13: 288-289.##
Carranza, E.J.M., Sadeghi, M., 2012. Primary geochemical characteristics of mineral deposits — implications for exploration. Ore Geology Reviews. 45: 1-4.##
Carranza, E.J.M., 2011. Analysis and mapping of geochemical anomalies using logratio-transformed stream sediment data with censored values. Journal of Geochemical Exploration 110: 167-185.##
Chaffee, M.A., 1976. The zonal distribution of selected elements above the Kalamazoo porphyry copper deposit, San Manuel district, Pinal County, Arizona. Journal of Geochemical Exploration 5: 145-165.##
Cheng, Q., Agterberg, F.P., Ballantyne, S.B., 1994. The separation of geochemical anomalies from background by fractal methods. J Geochem Explor. 51: 109-130.##
Cheng, Q., 1999: Spatial and scaling modeling for geochemical anomaly separation. J Geochem Explor. 65: 175-194.##
Daneshvar Saein, L., 2021. Recognition of gold mineralization potentials based on rock samples utilizing staged factor and fractal models, Bardaskan district (NE Iran). Journal of Mining and Environment. 10.22044/JME.2021.111562096.##
Farahmandfar, Z., Jafari, M.R., Afzal, P., Ashja Ardalan, A., 2020. Description of gold and copper anomalies using fractal and stepwise factor analysis according to stream sediments in NW Iran.Geopersia 10 (1): 135-148.##
Grigoryan, S.V., 1992. Mining Geochemistry. Nedra Publishing House, Moscow (in Russian). Hamami Pour, B., Tajeddin, H.A., Barahmand, L., 2014. Geology and geochemistry of Sebandoon gold mine, north of Bardaskan: Example of epithermal gold mineralization in Ophiolitic host rocks. Conference: 18th Symposium of the Geological Society of Iran. (In Persian with Enlish abstract).##
Hashemi, M., Afzal, P., 2013. Identification of geochemical anomalies by using of number-size (N-S) 392 Daneshvar Saein et al. fractal model in Bardaskan area, NE Iran. Arabian Journal of Geosciences. 6: 4785-4794.##
Hashemi, M., Afzal, P., Rasa, I., Noghreian, M., Khosro Tehrani, Kh., Vosoughi Abedini, M., 2010., Geochemical anomaly separation by concentration-area fractal model in Bardaskan area, NE Iran. Journal of Mining and Metallurgy 46 A (1): 1-10.##
Hashemi, M., 2010. Mineralogy, geochemistry and genesis of gold in north of Bardaskan, Khorasan Razavi (NE Iran). Unpublished Ph.D thesis, Islamic Azad University-Science and Research Branch.397 p. (In Persian with English abstract).##
Heidari, S.M., Afzal, P., Ghaderi, M., Sadeghi, B., 2021. Detection of mineralization stages using zonality and multifractal modeling based on geological and geochemical data in the Au-(Cu) intrusion-related Gouzal- Bolagh deposit, NW Iran, Ore Geology Reviews, 139: 104561.##
Hosseini S.A., Afzal P., Sadeghi B., Sharmad T., Shahrokhi S.V., Farhadinejad T. 2015. Prospection of Au mineralization based on stream sediments and lithogeochemical data using multifractal modeling in Alut 1:100,000 sheet, NW Iran. Arabian Journal of Geosciences. 8: 3867-3879.##
Imamalipour, I., Karimlou, M., Hajalilo, B., 2018. Geochemical zonality coefficients in the primary halo of Tavreh mercury prospect, northwestern Iran: Implications for exploration of listwaenitic type mercury deposits. Geochemistry: Exploration, Environment, Analysis. DOI: 10.1144/geochem2018-048.##
Jebeli, M., Afzal, P., Pourkermani, M., Jafari Rad, A., 2018. Correlation between rock types and Copper mineralization using fractal modeling in Kushk-e-Bahram deposit, Central Iran. Geopersia. 8, 131-141.##
Karaman, M., Kumral, Yildirim, M.D., Doner, K.Z., Afzal, P., Abdelnasser, A., 2021. Delineation of the porphyry- skarn mineralized zones (NW Turkey) using concentration-volume fractal model.Geochemistry. 81(4): 125802.##
Koohzadi, F., Afzal, P., Jahani, D., Pourkermani, M., 2021. Geochemical exploration for Li in regional scale utilizing Staged Factor Analysis (SFA) and Spectrum-Area (S-A) fractal model in north central Iran. Iranian Journal of Earth Sciences 13: 299-307##
Li, C.J., Ma, T.H., Shi, J.F., 2003. Application of a fractal method relating concentration and distances for separation of geochemical anomaly from background. J Geochem Explor. 77: 167-175.##
Li, Y., Zhang, D., Dai, L., Wan, G., Hou, B., 2016. Characteristics of structurally superimposed geochemical haloes at the polymetallic Xiasai silver-lead-zinc ore deposit in Sichuan Province, SW China. Journal of Geochemical Exploration. 169: 100-122.##
Lin, X., Hu, Y., Meng, G., Zhang, M., 2020. Geochemical patterns of Cu, Au, Pb and Zn in stream sediments from Tongling of East China: Compositional and geostatistical insights. Journal of Geochemical Exploration 210, 106457.##
Malaekeh, A., Ghasemi, M.R., Afzal, P., Solgi, A., 2021. Fractal modeling and relationship between thrust faults and carbonate-hosted Pb-Zn mineralization in Alborz Mountains, Northern Iran. Geochemistry. and carbonate-hosted Pb-Zn mineralization in Alborz Mountains, Northern Iran. Geochemistry. 125803.##
Mandelbrot, B.B., 1983. The Fractal Geometry of Nature, W.H. Freeman, San Francisco.##
Momeni, S., Shahrokhi, S.V., Afzal, P., Sadeghi, B., Farhadinejad, T., Nikzad, M.R., 2016. Delineation of the Cr mineralization based on the stream sediment data utilizing fractal modeling and factor analysis in the Khoy 1:100,000 sheet, NW Iran. BULLETIN OF THE MINERAL RESEARCH AND EXPLORATION. 152: 1-17.##
Nabilou, Afzal, P., M., Arian, M., Adib, A., Kheyrollahi, H., Foudazi M., Ansarirad, P., 2021. The relationship between Fe mineralization and the magnetic basement structures using multifractal modeling in the Esfordi and Behabad Areas (BMD), central Iran. Acta Geologica Sinica-English Edition. 14765##
Nabatian, Gh., Rastad, E., Neubauer, F., Honarmand, M., Ghaderi, M., 2015. Iron and Fe-Mn mineralisation in Iran: implications forTethyan metallogeny. Australian Journal of Earth Sciences 62, 211-241,
Nazarpour, A., 2018. Application of C-A fractal model and exploratory data analysis (EDA) to delineate geochemical anomalies in the: Takab 1:25,000 geochemical sheet, NW Iran. Iranian Journal of Earth Sciences. 10: 173-180.##
Reimann, C., Filzmoser, P., Garrett, R. G. 2002. Factor analysis applied to regional geochemical data: problems and possibilities. Applied Geochemistry. 17(3): 185-206. Geopersia 2022, 12(2): 379-394 393##
Rezaei, S., Lotfi, M., Afzal, P., Jafari, M.R., Shamseddin Meigoony, M., 2015. Delineation of Cu prospects utilizing multifractal modeling and stepwise factor analysis in Noubaran 1:100,000 sheet, Center of Iran. Arabian Journal of Geosciences 8: 7343-7357.##
Robb, L., 2005. Introduction to Ore-Forming Processes, Blackwell Publishing, Oxford. 373 p.##
Roslyakov, N.A., 1984. Zonality of gold forms in the surficial environment as a criterion for buried gold deposits, Journal of Geochemical Exploration 21: 333-340.##
Saadati, H., Afzal, P., Torshian, H., Solgi, A., 2020. Geochemical exploration for Li using Geochemical Mapping Prospectivity Index (GMPI), fractal and Stage Factor Analysis (SFA) in NE Iran. Geochemistry: Exploration, Environment, Analysis 20: 461-472.##
Sadeghi, B. 2020. Quantification of Uncertainty in Geochemical Anomalies in Mineral Exploration. PhD thesis, University of New South Wales.##
Sadeghi, B., Grunsky E., Pawlowsky-Glahn V. 2021a. Uncertainty Quantification. In: Daya Sagar B., Cheng Q., McKinley J., Agterberg F. (eds) Encyclopedia of Mathematical Geosciences. Encyclopedia of Earth Sciences Series. Springer, Cham.
Sadeghi, B., Zhao, H., Holzheid, A. 2021b. Preface: Mineral exploration: a journey from fieldwork, to laboratory work, computational modelling and mineral processing, Geochemistry, Special Issue of “Mineral exploration: a journey from fieldwork, to laboratory work, computational modelling and mineral processing”. 81, /j.chemer.2021.125825.##
Sadeghi, B., 2021a. Concentration-Area Plot. In: Daya Sagar B., Cheng Q., McKinley J., Agterberg F.(eds) Encyclopedia of Mathematical Geosciences. Encyclopedia of Earth Sciences Series. Springer,Cham.
Sadeghi, B. 2021b. Spectrum-Area Method. In: Daya Sagar B., Cheng Q., McKinley J., Agterberg F. (eds) Encyclopedia of Mathematical Geosciences. Encyclopedia of Earth Sciences Series. Springer, Cham.
Sadeghi, B., 2021c. Concentration-concentration fractal modelling: a novel insight for correlation between variables in response to changes in the underlying controlling geological-geochemical processes, Ore Geology Reviews.
Sadeghi, B., 2021d. Simulated-multifractal models: a futuristic review of multifractal modeling in geochemical anomaly classification, Ore Geology Reviews. : .2021.104511.##
Sadeghi, B., Agterberg F. , 2021. Singularity Analysis. In: Daya Sagar B., Cheng Q., McKinley J., Agterberg F. (eds) Encyclopedia of Mathematical Geosciences. Encyclopedia of Earth Sciences Series. Springer, Cham.
Sadeghi, B., Cohen, D.R. 2021, Concentration-distance from centroids (C-DC) multifractal modeling: A novel approach to characterizing geochemical patterns based on sample distance from mineralization, Ore Geology Reviews.
Sadeghi, B., Cohen, D.R., Category-based fractal modelling: A novel model to integrate the geology into the data for more effective processing and interpretation, Journal of Geochemical Exploration. 2021. 106783.##
Sadeghi, B., Madani, N., Carranza, E.J.M., 2015. Combination of geostatistical simulation and fractal modelling for mineral resource classification, Journal of Geochemical Exploration. 149, 59-73.##
Sadeghi, B., Moarefvand, P., Afzal, P., Yasrebi, A.B., Daneshvar Saein, L., 2012. Application of fractal models to outline mineralized zones in the Zaghia iron ore deposit, Central Iran. Journal of Geochemical Exploration. 122: 9-19.##
Shamseddin Meigoony, M., Afzal, P., Gholinejad, M., Yasrebi, A.B., Sadeghi, B., 2014. Delineation of geochemical anomalies using factor analysis and multifractal modeling based on stream sediments data in Sarajeh1:100,000 sheet, Central Iran. Arabian Journal of Geosciences. 7: 5333-5343.##
Shamseddin Meigooni, M., Lotfi, M., Afzal, P., Nezafati, N., Kargar Razi, M., 2021. Application of multivariate geostatistical simulation and fractal analysis for detection of rare earth elements (REEs) geochemical anomalies in Esfordi phosphate mine, Central Iran. Geochemistry: Exploration, Environment, Analysis. 21 geochem2020-035: 1-17.##
Torshizian, H., Afzal, P., Rahbar, K., Yasrebi, A.B., Wetherelt, A., Fyzollahhi, N., 2021. Application of modified wavelet and fractal modeling for detection of geochemical anomaly. Geochemistry. 81(4): 125800.##
Treiblmaier, H., Filzmoser, P., 2010. Exploratory factor analysis revisited: How robust methods support the detection of hidden multivariate data structures in IS research. Information & management 47(4): 197-207.##
Yasrebi, A.B., Hezarkhani, A., 2019. Resources classification using fractal modelling in Eastern Kahang Cu-Mo porphyry deposit, Central Iran. Iranian Journal of Earth Sciences 11: 56-67.##
Yousefi, M., Kamkar-Rouhani, A., Carranza, E. J. M., 2012. Geochemical mineralization probability index (GMPI): a new approach to generate enhanced stream sediment geochemical evidential map for increasing probability of success in mineral potential mapping. Journal of Geochemical Exploration. 115: 24-35.##
Yousefi, M., Kamkar-Rouhani, A., Carranza, E.J.M., 2014. Application of staged factor analysis and logistic function to create a fuzzy stream sediment geochemical evidence layer for mineral prospectivity mapping. Geochemistry: Exploration, Environment, Analysis. 14(1): 45-58.##
Zadmehr, F., Shahrokhi, S.V., 2019. Separation of geochemical anomalies by concentration-area and concentration-number methods in the Saqez 1:100,000 sheet, Kurdistan. Iranian Journal of Earth Sciences 11: 196-204.##
Ziaii, M., Carranza, E.J.M., Ziaei, M. 2011. Application of geochemical zonality coefficients in mineral prospectivity mapping. Computers & Geosciences 37: 1935-1945.##
Ziaii, M., Doulati Ardejani, F., Ziaei, M., Soleymani, A.A., 2012. Neuro-fuzzy modeling based genetic algorithms for identification of geochemical anomalies in mining geochemistry. Applied Geochemistry 27: 663-676.##
Ziaii, M., Safari, S., Timkin, T., Voroshilov, V., Yakich, T., 2019. Identification of geochemical anomalies of the porphyry-Cu deposits using concentration gradient modelling: A case study, Jebal- Barez area, Iran. Journal of Geochemical Exploration 199: 16-30.##
Zissimos, A.M., Cohen, D.R., Christoforou, I.C., Sadeghi, B., Rutherford, N.F. 2021. Controls on soil geochemistry fractal characteristics in Lemesos (Limassol), Cyprus, Journal of Geochemical Exploration. 220,
Zuo, R., 2011. Identifying geochemical anomalies associated with Cu and Pb-Zn skarn mineralization using principal component analysis and spectrum-area fractal modeling in the Gangdese Belt, Tibet (China). J Geochem Explor. 111: 13-22.##