A Geostatistical Simulation of a Mineral Deposit using Uncertain Experimental Data

Abstract

In the geostatistical modeling and characterization of natural resources, the traditional approach for determining the spatial distribution of a given deposit using stochastic sequential simulation is to use the existing experimental data (i.e., direct measurements) of the property of interest as if there is no uncertainty involved in the data. However, any measurement is prone to error from different sources, for example from the equipment, the sampling method, or the human factor. It is also common to have distinct measurements for the same property with different levels of resolution and uncertainty. There is a need to assess the uncertainty associated with the experimental data and integrate it during the modeling procedure. This process is not straightforward and is often overlooked. For the reliable modeling and characterization of a given ore deposit, measurement uncertainties should be included as an intrinsic part of the geo-modeling procedure. This work proposes the use of a geostatistical simulation algorithm to integrate uncertain experimental data through the use of stochastic sequential simulations with local probability functions. The methodology is applied to the stochastic modeling of a benchmark mineral deposit, where certain and uncertain experimental data co-exist. The uncertain data is modeled by assigning individual probability distribution functions to each sample location. Different strategies are proposed to build these local probability distributions. Each scenario represents variable degrees of uncertainty. The impacts of the different modeling approaches on the final deposit model are discussed. The resulting models of these proposed scenarios are also compared against those retrieved from previous studies that use conventional geostatistical simulation. The results from the proposed approaches showed that using stochastic sequential simulation with local probability functions to represent local uncertainties decreased the estimation error of the resulting model, producing fewer misclassified ore blocks.

Geometallurgical Simulation of the Work Index in a Porphyry Copper Deposit Using Geostatistical Techniques

“…It is a technique that allows obtaining realizations that reproduce the statistics and spatial variability of the original data (Narciso et al, 2019) achieving an unsmoothed representation of reality (Abzalov, 2016). In the study of geometallurgical variables Sequential Gaussian Simulation "SGS" is used (Hosseini & Asghari, 2015), which requires normal distribution in the samples.…”

Geostatistical simulations with heterotopic hard and soft data without modeling the linear model of coregionalization

“…To the authors' knowledge, the method has not been applied before. Similar to other approaches (Cuba, 2012;Barnett and Deutsch (2015); Silva and Deutsch (2018); Soares et al (2017); Neves et al (2018); Narciso et al (2019) and Araujo et al ( 2019)), we start by generating a series of datasets at the location of the soft datum. The generation of the datasets is performed by p-field simulation (Srivastava 1992).…”