Nonlinear disjunctive kriging for the estimating and modeling of a vein copper deposit
Subject Areas :
Mineralogy
Ali Akbar Daya
1
1 - Department of Mining Engineering, University of Sistan and Baluchestan, Zahedan, Iran
Received: 2018-08-12
Accepted : 2019-03-04
Published : 2019-07-01
Keywords:
Disjunctive kriging,
Chelkureh,
Vein type,
Zahedan,
Abstract :
Estimation of mineral resources and reserves with low values of error is essential in mineral exploration. The aim of this study is to estimate and model a vein type deposit using disjunctive kriging method. Disjunctive Kriging (DK) as an appropriate nonlinear estimation method has been used for estimation of Cu values. For estimation of Cu values and modeling of the distribution of Cu in Chelkureh, samples have been taken from 48 drill holes in Chelkureh, and the values of Cu have been analyzed. Resulting data from analyzing Cu values were converted to standard normal values using Hermite polynomials. Variography has been done in the Chelkureh deposit. After studying variograms in different directions, it was found out that the ore deposit has a mild anisotropy. The best-fitted variogram model was considered for disjunctive kriging estimation. The model consists of a pure nugget effect with 0.46 amplitude plus a spherical scheme with sill 1.20 and range 140 m. Consequently, a three-dimensional model of estimated value and error estimated value was provided by disjunctive kriging to divide the ore into an economic and uneconomic part. The models based on the estimate of the DK method in the study area exhibited an increasing trend of concentration from the center to North. Finally, validation between the disjunctive kriging carried out by using cross-validation. The result showed that the correlation of estimated values and real values was strong (63.4%).
References:
Afzal P, Shahbeik Sh, Moarefvand P, Yasrebi AB, Zuo R, Wetherelt A (2013) 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 6:78-90.
Chiles JP, Delfiner P (1999) Geostatistics: Modeling Spatial Uncertainty, Wiley.
Daya AA (2012) Reserve estimation of central part of Choghart north anomaly iron ore deposit through ordinary kriging method, International Journal of Mining Science and Technology 22: 573-577.
Daya AA (2014) Application of disjunctive kriging for estimating economic grade distribution in an iron ore deposit: a case study of the Choghart North Anomaly, Iran, Journal of the Geological Society of India 83: 567–576.
Daya AA (2015a) Ordinary Kriging for the estimation of vein type copper deposit: A case study of the Chelkureh, Iran, Journal of Mining and Metallurgy 51:1-14.
Daya AA (2015b) Application of median indicator kriging in the analysis of an iron mineralization, Arabian journal of Geosciences 8:367-377.
Daya AA, Bejari H (2015) A comparative study between simple kriging and ordinary kriging for estimating and modeling the Cu concentration in Chelkureh deposit, SE Iran, Arabian journal of Geosciences 8: 6003-6020.
Daya AA, Hosseininasab M (2019) Application and comparison of the cokriging and the fractal model for identifying geochemical anomalies in Janja area, SE Iran, International Journal of Mining and Mineral Engineering 10: 1-26.
Deutsch CV, Journel AG (1998) GSLIB: Geostatistical software library and user’s guide, second ed, Oxford University Press, New York, NY, 369p.
Emery X (2005) Simple and ordinary multigaussian kriging for estimating recoverable reserves, Mathematical Geology 37: 295-319.
Emery X (2006) A Disjunctive Kriging Program for Assessing Point-Support Conditional Distributions, Computers & Geosciences 32: 965–983.
Hassanipak AA, Sharafaddin M (2001) Exploration Data Analysis, University of Tehran Press (UTP), Tehran (In Persian).
Journel AG, Huijbregts CJ (1978) Mining Geostatistics, Academic Press, London, 600 pp.
Maanijou M (2007) Geochemistry, origin of ore fluids, and formation of Chehelkureh copper deposit (NW of Zahedan): Ph.D. Thesis, Tehran, Shahid Beheshti University, 236 p (in Persian with English abstract).
Maanijou M, Lentz DR, Rasa I and Alirezaei S (2008) Petrography and alteration of Chehelkureh copper deposit: Mass balance of elements and behavior of REE, Geosciences of Iran 17: 86–101 (in Persian with English abstract).
Maanijou M, Rasa I, Lentz RD (2012) Petrology, geochemistry, and stable isotope studies of the Chelkureh Cu-Zn-Pb deposit, Zahedan, Iran, Economic Geology 107:683–712.
Matheron G (1984) Isofactorial models and change of support. In: Verly, G., David, M., Journel, A.G., Mare’chal, A. (Eds.), Geostatistics for Natural Resources Characterization. Reidel, Dordrecht 449–467.
Ortiz JM, Oz B, Deutsch CV (2004) A Step by Step Guide to Bi-Gaussian Disjunctive Kriging, Geostatistics Banff 14: 1097-1102.
Rivoirard J (1994) Introduction to disjunctive kriging and nonlinear geostatistics, Clarendon Press (Oxford) 180p.
Stocklin JO (1977) Structural correlation of the Alpine ranges between Iran and Central Asia. Mémoires Hors Série Soc Geol France 8 : 333–353.
Tirrul R, Bell IR, Griffis RJ, Camp VE (1983) The Sistan suture zone of eastern Iran. Geological Society of America Bulleti 94: 134–150.
Valeh N, Saeedi A (1989) Geological map of Chelkureh, Geological Society of Iran, Sheet 8050, scale 1:250,000.
Verly G (1983) The multigaussian approach and its applications to the estimation of local reserves, Mathematical Geology 15:259–286.
Vural A. (2014). Trace/heavy metal accumulation in soil and in the shoots of acacia tree, Gümüşhane-Turkey. Bulletin of the Mineral Research and Exploration 148:85-106.
Webster R, Oliver M A (2001) Geostatistics for environmental scientists, Wiley, UK.
