Studies of the effects of outliers and data transformation on variogram estimates for a base metal and a gold ore body

  • Daniel G. Krige
  • Eduardo J. Magri


Variograms for gold and lead values from the Loraine and Prieska mines, respectively, indicate that data outliers can seriously distort and/or mask the real variogram patterns. Studies show that this problem is best overcome for these mines by logarithmic transformation of the data, and/or a suitable screening out of such outliers, and/or more robust variogram estimation procedures; the benefits are particularly significant when the basic data is limited.

Key words

geostatistics variogram outliers 


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  1. Cressie, N. and Hawkins, D. M., 1980, Robust estimation of the variogram:Jour. Math. Geol., v. 12.Google Scholar
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  3. Krige, D. G., 1981, Lognormal-de Wijsian geostatistics for ore evaluation (2nd ed.): S.A.I.M.M. Monograph Series No. 1.Google Scholar
  4. Krige, D. G. and Magri, E. J., 1982, Geostatistical case studies of the advantages of lognormal-de Wijsian kriging with mean for a base metal mine and a gold mine: Jour. Math. Geol., v. 14, p. 547–555.Google Scholar

Copyright information

© Plenum Publishing Corporation 1982

Authors and Affiliations

  • Daniel G. Krige
    • 1
  • Eduardo J. Magri
    • 2
  1. 1.Department of Mineral EconomicsUniversity of WitwatersrandJohannesburgSouth Africa
  2. 2.Operations Research and Geostatistics DivisionAnglo Transvaal Cons. Inv. Co. LtdJohannesburgSouth Africa

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