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Compositions, Logratios And Geostatistics: An Application To Iron Ore, Clint Ward
Compositions, Logratios And Geostatistics: An Application To Iron Ore, Clint Ward
Theses: Doctorates and Masters
Common implementations of geostatistical methods, kriging and simulation, ignore the fact that geochemical data are usually reported in weight percent, sum to a constant, and are thus compositional in nature. The constant sum implies that rescaling has occurred and this can be shown to produce spurious correlations. Compositional geostatistics is an approach developed to ensure that the constant sum constraint is respected in estimation while removing dependencies on the spurious correlations. This study tests the applicability of this method against the commonly implemented ordinary cokriging method. The sample data are production blast cuttings analyses drawn from a producing iron ore …
Wavelet-Based Simulation Of Geological Variables, T. T. Tran
Wavelet-Based Simulation Of Geological Variables, T. T. Tran
Theses: Doctorates and Masters
This thesis introduces a number of conditional simulation algorithms using wavelet bases. These make use of two orthogonal wavelet bases, the Haar and the Db2 bases. Firstly, two single-level algorithms are introduced, HSIM: with the Haar basis and DB2SIM with the Db2 basis. HSIM reproduces the histogram and semivariogram model of isotropic samples but not the semivariogrnm model of anisotropic samples. DB2SIM reproduces the histogram and semivariogram model in both the isotropic and anisotropic cases but, because of the conditioning method employed, is not as computationally efficient as we would wish. Because of the limitations of HSIM and Db2SIM two …
Geostatistical Optimisation Of Sampling And Estimation In A Nickel Laterite Deposit, Mark P. Murphy
Geostatistical Optimisation Of Sampling And Estimation In A Nickel Laterite Deposit, Mark P. Murphy
Theses: Doctorates and Masters
Nickel and cobalt are key additives to metal alloys in modem industry. The largest worldwide nickel-cobalt resources occur in nickel laterite deposits that have formed during the chemical weathering of ultramafic rocks at the Earth's surface. At the Murrin Murrin mine in Western Australia, the nickel laterite deposits occur as laterally extensive, undulating blankets of mineralisation with strong vertical anisotropy, near normal nickel distributions, and positively skewed cobalt distributions. The mineral resources in nickel laterite deposits in Murrin Murrin are usually estimated from drilling and sampling on relatively wide-spaced drill patterns that are supported by local clusters of close-spaced sampling. …