Detection of rare earth element anomalies in Esfordi phosphate deposit of Central Iran, using geostatistical-fractal simulation

Document Type : Research Paper


1 Department of Earth Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Department of Geology, North Tehran Branch, Islamic Azad University, Tehran, Iran

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

4 Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran


This study is aimed to determine geochemical anomalies of rare earth elements (REEs) and provides a concentration distribution map for the Esfordi phosphate deposit (EPD), Bafq metallogenic province (BMP), Central Iran. With an average grade of 5519 ppm for REEs, the EPD is one of the prominent deposits of the region. In this research, sequential Gaussian simulation (SGS) and concentration-area (C-A) fractal modeling are used to determine concentration anomalies and provide a ∑REEs concentration map based on surface data. The log-ratio matrix is used to investigate the mineralization processes, determining the relationships between the anomalies and the rock units, and validating the results of SGS fractal modeling. The results are indicating that the main anomaly has strong correlation with the apatite-iron, and in particular, with the apatite mineralization, which can be considered as an exploration guide. The results also confirm the efficiency of simultaneous application of fractal modeling and SGS simulation.


Article Title [Persian]


Afzal, P., Aramesh Asl, R., Adib, A., Yasrebi, A.B., 2015. Application of fractal modelling for Cu
mineralisation reconnaissance by ASTER multispectral and stream sediment data in Khoshname
area, NW Iran. Journal of the Indian Society of Remote Sensing 43(1): 121-132.##
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(3): 220-232.##
Afzal, P., Khakzad, A., Moarefvand, P., Rashidnejad Omran, N., Esfandiari, B., Fadakar Alghalandis, Y., 2010. Geochemical anomaly separation by multifractal modeling in Kahang (Gor Gor) porphyry system, Central Iran. Journal of Geochemical Exploration 104(1-2): 34-46.##
Afzal, P., Mirzaei, M., Yousefi, M., Adib, A., Khalajmasoumi, M., Zia Zarifi, A., Foster, P., Yasrebi, A.B., 2016. Delineation of geochemical anomalies based on stream sediment data utilizing fractal modeling and staged factor analysis. Journal of African Earth Sciences 119: 139-149.##
Afzal, P., Shahbeik, S., Moarefvand, P., Yasrebi, A.B., Zuo, R., Wetherelt, A., 2014. The Effect of Estimation Methods on Multifractal Modeling for Mineralized Zone Delineation in the Dardevey Iron Ore Deposit, NE Iran. Iranian Journal of Earth Sciences 6(1): 78-90.##
Afzal, P., Yasrebi, A.B., Daneshvar Saein, L., Panahi, S., 2017. Prospecting of Ni mineralization based on geochemical exploration in Iran. Journal of Geochemical Exploration 181: 294-304.##
Afzal, P., Yusefi, M., Mirzaie, M., Ghadiri-Sufi, E., Ghasemzadeh, S., Daneshvar Saein, L., 2019.
Delineation of podiform-type chromite mineralization using geochemical mineralization prospectivity index and staged factor analysis in Balvard area (SE Iran). Journal of Mining and
Environment 10(3): 705-715.##
Afzal, P., Zia Zarifi, A., Farhadi Khankandi, S., Wetherelt, A., Yasrebi, B.A., 2012. Separation of
uranium anomalies based on geophysical airborne analysis by using Concentration-Area (CA)
128 Shamseddin Meigooni et al. Fractal Model, Mahneshan 1: 50000 Sheet, NW IRAN. Journal of Mining and Metallurgy A: Mining 48(1): 1-11.##
Agterberg, F., 1995. Multifractal modeling of the sizes and grades of giant and supergiant deposits. International Geology Review 37(1): 1-8.##
Ahmadfaraj, M., Mirmohammadi, M., Afzal, P., Yasrebi, A.B., Carranza, E.J., 2019. Fractal modeling and fry analysis of the relationship between structures and Cu mineralization in Saveh region, Central Iran. Ore Geology Reviews 107: 172-185.##
Asghari, O., Soltni, F., Bakhshandeh Amnieh, H., 2009. The comparison between sequential gaussian simulation (SGS) of Choghart ore deposit and geostatistical estimation through ordinary kriging. Australian Journal of Basic and Applied Sciences 3(1): 330-341.##
Bonyadi, Z., Davidson, G.J., Mehrabi, B., Meffre, S., Ghazban, F., 2011. Significance of apatite REE depletion and monazite inclusions in the brecciated Se–Chahun iron oxide–apatite deposit, Bafq district, Iran: insights from paragenesis and geochemistry. Chemical Geology 281(3-4): 253-269.##
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(2): 167-185.##
Carranza, E.J.M., 2017. Geochemical mineral exploration: should we use enrichment factors or logratios? Natural Resources Research 26(4): 411-428.##
Carranza, E.J.M., Zuo, R., Cheng, Q., 2012. Fractal/multifractal modelling of geochemical exploration data. Journal of Geochemical Exploration 122: 1-3.##
Chen, F., Chen, S., Peng, G. 2012. Using sequential gaussian simulation to assess geochemical anomaly areas of lead element. In: International Conference on Computer and Computing Technologies in Agriculture. Springer, 69-76.##
Cheng, Q., Agterberg, F., Ballantyne, S., 1994. The separation of geochemical anomalies from
background by fractal methods. Journal of Geochemical Exploration 51(2): 109-130.##
Cheuiche Godoy, M., Dimitrakopoulos, R., Costa, J.F. 2001. Economic functions and geostatistical simulation applied to grade control. In: The Australasian Institute of Mining and Metallurgy, 591-599.##
Daliran, F., 2002. Kiruna-type iron oxide-apatite ores and apatitites of the Bafq district, Iran, with an emphasis on the REE geochemistry of their apatites. Hydrothermal iron oxide copper gold and related deposits: a global perspective 2: 303-320.##
Daneshvar Saein, L., Afzal, P., 2017. Correlation between Mo mineralization and faults using
geostatistical and fractal modeling in porphyry deposits of Kerman Magmatic Belt, SE Iran. Journal of Geochemical Exploration 181: 333-343.##
David, M., 1970. Geostatistical ore reserve estimation, Elsevier, Amsterdam, 1-283.
Davis, J.C., 2002. Statistics and data analysis in geology, John Wiley and Sons Inc., New York, 1- 638.##
Deutsch, C., 2002. Goestatistical reservoir modeling, Oxford University Press, New York, 1-371.
Deutsch, C.V., Journel, A.G., 1992. Geostatistical software library and user’s guide, Oxford University Press, New York, 1-340.##
Dubrule, O., 2003. Geostatistics for seismic data integration in earth models, Society of Exploration Geophysicists and European Association of Geoscientists and Engineers, Oklahoma, 1-283.##
Emery, X., Lantuéjoul, C., 2006. Tbsim: A computer program for conditional simulation of threedimensional gaussian random fields via the turning bands method. Computers & Geosciences 32(10): 1615-1628.##
Farahmandfar, Z., Jafari, M., 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.##
Foerster, H., Jafarzadeh, A., 1994. The Bafq mining district in central Iran; a highly mineralized
Infracambrian volcanic field. Economic Geology 89(8): 1697-1721.##
Gholampour, O., Hezarkhani, A., Maghsoudi, A., Mousavi, M., 2019. Delineation of alteration zones based on kriging, artificial neural networks, and concentration–volume fractal modelings in hypogene zone of Miduk porphyry copper deposit, SE Iran. Journal of Mining and Environment 10(3): 575-595.##
Goncalves, M.A., Mateus, A., Oliveira, V., 2001. Geochemical anomaly separation by multifractal
modelling. Journal of Geochemical Exploration 72(2): 91-114.##
Goovaerts, P., 1997. Geostatistics for natural resources evaluation, Oxford University Press, New York, Geopersia 2021, 11(1): 115-130 129 1-483.##
Goovaerts, P., 2008. Kriging and semivariogram deconvolution in the presence of irregular geographical units. Mathematical Geosciences 40(1): 101-128.##
Haghipour, A., 1964. Iron ore deposits in Central Iran, in relation to structural geology and
metamorphism, scapolitization and albitization. Journal of Iranian Petroleum Institute 76: 1-9.##
Hajsadeghi, S., Asghari, O., Mirmohammadi, M., Afzal, P., Meshkani, S.A., 2017. Uncertainty-Volume fractal model for delineating copper mineralization controllers using geostatistical simulation in Nohkouhi volcanogenic massive sulfide deposit, Central Iran. Maden Tetkik ve Arama Dergisi (159): 1-10.##
Hassanpour, S., Afzal, P., 2013. Application of concentration–number (C–N) multifractal modeling for geochemical anomaly separation in Haftcheshmeh porphyry system, NW Iran. Arabian Journal of Geosciences 6(3): 957-970.##
Hawkes, H.E., Webb, J.S., 1979. Geochemistry in mineral exploration, Academic Press, New York, 1- 657.##
Jami, M. 2006. Geology, geochemistry and evolution of the Esfordi phosphate-iron deposit, Bafq area, Central Iran. In: University of New South Wales, Australia.##
Jami, M., Dunlop, A.C., Cohen, D.R., 2007. Fluid inclusion and stable isotope study of the Esfordi apatite-magnetite deposit, Central Iran. Economic Geology 102(6): 1111-1128.##
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(1): 131-141.##
Journel, A., 1980. The lognormal approach to predicting local distributions of selective mining unit grades. Journal of the International Association for Mathematical Geology 12(4): 285-303.##
Journel, A.G., 1974. Geostatistics for conditional simulation of ore bodies. Economic Geology 69(5): 673-687.##
Journel, A.G., Huijbregts, C.J., 1978. Mining geostatistics, Academic press, London, 1-600.##
Kühn, C., Visser, J.K., 2014. Managing uncertainty in typical mining project studies. South African Journal of Industrial Engineering 25(2): 105-120.##
Machuca-Mory, D.F., Deutsch, C.V., 2009. Sequential Gaussian and Indicator Simulation with
Location-Dependent Distributions and Statistics. Centre for Computational Geostatistics 11.
Madani Esfahani, N., Asghari, O., 2013. Fault detection in 3D by sequential Gaussian simulation of Rock Quality Designation (RQD). Arabian Journal of Geosciences 6(10): 3737-3747.##
Manchuk, J.G. 2010. Geostatistical modeling of unstructured grids for flow simulation. In: University of Alberta, Canada. Mandelbrot, B.B., 1983. The fractal geometry of nature, WH freeman, New York, 1-468.##
Mokhtari, M.A.A., 2015. Posht-e-Badam metallogenic block (central Iran): A suitable zone for REE mineralization. Central European Geology 58(3): 199-216.##
Nas, B., 2009. Geostatistical Approach to Assessment of Spatial Distribution of Groundwater Quality. Polish Journal of Environmental Studies 18(6): 1073–1082.##
Navidi, A., Ziaii, M., Afzal, P., Yasrebi, A.B., Wetherelt, A., Foster, P., 2014. Determination of
chromites prospects using multifractal models and zonality index in the parang 1: 100000 sheet, Iran. Universal Journal of Geoscience 2(4): 133-139.##
Nazarpour, A., Sadeghi, B., Sadeghi, M., 2015. Application of fractal models to characterization and evaluation of vertical distribution of geochemical data in Zarshuran gold deposit, NW Iran. Journal of Geochemical Exploration 148: 60-70.##
Pardo-Igúzquiza, E., Atkinson, P.M., 2007. Modelling the semivariograms and cross-semivariograms required in downscaling cokriging by numerical convolution–deconvolution. Computers & Geosciences 33(10): 1273-1284.##
Queiroz, J.C.B., Sturaro, J.R., Riedel, P.S. 2001. Geostatistic Mapping of Arsenic, Manganese and Iron Contamination Risk in the Port of Santana, Amapa, Brazil. In: Annual Conf. of Int. Association for Mathematical Geology. Cancun, Mexico.##
Rezaie, M., Afzal, P., 2016. The effect of estimation methods on fractal modelling for anomales' detection in the Irankuh area, Central Iran. Geopersia 6(1): 105-116.##
Shahsavar, S., Jafari Rad, A., Afzal, P., Nezafati, N., 2020. Selection of Optimum Fractal Model for Detection of Stream Sediments Anomalies. Geopersia, 10.22059/GEOPE.2020.293961.648516.##
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 Sarajeh 1: 100,000 sheet, Central Iran. Arabian Journal of Geosciences 7(12): 5333-5343.##
Soltani, F., Afzal, P., Asghari, O., 2014. Delineation of alteration zones based on Sequential Gaussian Simulation and concentration–volume fractal modeling in the hypogene zone of Sungun copper deposit, NW Iran. Journal of Geochemical Exploration 140: 64-76.##
Stosch, H.-G., Romer, R.L., Daliran, F., Rhede, D., 2011. Uranium–lead ages of apatite from iron oxide ores of the Bafq District, East-Central Iran. Mineralium Deposita 46(1): 9-21.##
Taghipour, S., Kananian, A., Mackizadeh, M.A., K Somarin, A., 2015. Skarn mineral assemblages in the Esfordi iron oxide–apatite deposit, Bafq district, Central Iran. Arabian Journal of Geosciences 8(5): 2967-2981.##
Torab, F., Lehmann, B., 2007. Magnetite-apatite deposits of the Bafq district, Central Iran: apatite geochemistry and monazite geochronology. Mineralogical Magazine 71(3): 347-363.##
Torab, F.M. 2008. Geochemistry and metallogeny of magnetite apatite deposits of the Bafq mining district, Central Iran. In: Clausthal University of Technology, Germany.Wang, X.-q., 2003. Exploration geochemistry: Past achievements and future challenges. Earth Science
Frontiers 10(1): 239-248.##
Webster, R., Oliver, M.A., 2007. Geostatistics for environmental scientists, John Wiley & Sons, New York, 1-270.##
Yasrebi, A.B. 2014. Determination of an Ultimate Pit Limit Utilising Fractal Modelling to Optimise NPV. In: University of Exeter, Exeter, UK.##
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(1): 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.##
Zuo, R., 2011a. Decomposing of mixed pattern of arsenic using fractal model in Gangdese belt, Tibet, China. Applied Geochemistry 26: 271-273.##
Zuo, R., 2011b. 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). Journal of Geochemical Exploration 111(1-2): 13-22.##
Zuo, R., Cheng, Q., Xia, Q., 2009. Application of fractal models to characterization of vertical
distribution of geochemical element concentration. Journal of Geochemical Exploration 102(1): 37-43.##
Zuo, R., Wang, J., 2016. Fractal/multifractal modeling of geochemical data: A review. Journal of
Geochemical Exploration 164: 33-41.##
Zuo, R., Xia, Q., 2009. Application fractal and multifractal methods to mapping prospectivity for
metamorphosed sedimentary iron deposits using stream sediment geochemical data in eastern Hebei province, China. Geochimica et Cosmochimica Acta 73: A1540##