Probabilistic modeling and uncertainty quantification of weathering crustal horizons of San Felipe nickel deposit

Abstract

The geological modeling commonly performed on mineral deposits is of the deterministic type, but it has been demonstrated that probabilistic modeling is more adequate to know or quantitatively measure the associated uncertainty. This study is aim to quantify the uncertainty of weathering crustal horizons for a sector of the San Felipe nickel deposit, based on its probabilistic modeling. The descriptive geological model of the lateritic deposit was taken as a basis, characterized by the lithological zoning at depth. The probabilistic Sequential Indicator Simulation with Locally variable Proportions was used, through which 50 equiprobable scenarios of the geological units are synthetically reproduced, conditioned to 3,884 composites from the network of 100 m x 100 m drillholes. As a result, the 3D model of the lithological horizons on block support is presented for the study sector, as well as the entropy maps that quantify the uncertainty associated with the model of the modeled geological units. As conclusion, we can say that, due to the variability present in this type of lateritic deposit, the availability of geological information is still insufficient to reproduce the model of weathering crust horizons with an adequate level of certainty.