Evaluation of performance of non-linear geostatistical estimation methods to estimate tonnage-grade of the Chah-‎bashe iron deposit, Yazd province‎


1 Mining Engineering Department, Geosciences Engineering College, Arak University of Technology

2 PhD Candidate of Mining Engineering, Mining Engineering College, University of Tehran


In this research, non-linear geostatistical methods containing block ordinary log-kriging, indicator kriging and sequential ‎gaussian simulation as well as inverse squared distance from statistical methods (for comparison) have been employed ‎to evaluate grade and ore reserve of the Chah-bashe iron deposit, Yazd provice. To achieve this goal, first statistical ‎studies of assay data of exploratory boreholes were performed through determination of descriptive statistics, drawing ‎the histograms and cumulative probability distribution diagrams of the data. For modeling the deposit, variography ‎was also carried out through drawing various directional variograms using SGEMs software, MATLAB functions and ‎short programming in this environment. Afterward, 3-D block modeling of the deposit, determination of average grade, ‎ore reserve estimation and plotting tonnage-grade diagrams were performed using Datamine software. The results of ‎the research show that sequential gaussian simulation, indicator kriging, ordinary log-kriging, and inverse squared ‎distance‏ ‏methods have the minimum estimation variance, respectively. Although all selected methods are the most ‎accurate geostatistical methods, however the results of sequential gaussian simulation method by applying various ‎filters on the data such as using residual maps, is most highly accurate and more reliable so has more validity. ‎


Ahmadi, R., 2010. Application of statistical patterns for ore reserve estimation emphasis to Ali-abad, Yazd copper mine. Arak University of Technology, Vice Chancellor for Research, Arak, 102 pp.
Bohling, G., 2007. SGeMS Tutorial Notes, 26 pp.
Hassani-Pak, A.A., Sharafodin, M.S., 2001. Exploration data analysis. Tehran University Press, 987 pp.
Rendu, J.M., 1981. An introduction to geostatistical methods of mineral evaluation, South African Institute of Mining and Metallurgy monograph series, Johannesburg, 84 pp.  
Yousefi, M., Jaafarzadeh, A.O., Karami, A. and Fereidooni, H., 2013. Detailed exploration report of the region of Chah-bashe deposit, Iran Minerals Supply and production Co., Tehran, 125R4-02, 67 pp.