Using Stochastic Borehole Seismic Velocity Tomography and Bayesian Simulation to Estimate Ni, Cu and Co Grades

In the mining industry, conventional methods to build a block models of ore deposits are based on kriging or cokriging of grades for targeted minerals measured on core sample in fertile geologicals units. As the complexity of geological geometry increases, so does the complexity of the grade estimation. Without additional information on the geological framework, the definition of fertile zone is a low-precision exercise that requires extensive experience from the geologist. Recently, thanks to computer and geophysical tool improvements, seismic tomography became very attractive for many application fields. Indeed, this non-intrusive technique allows inferring the mechanical properties of the ground using travel times and amplitude analysis of the transmitted wavelet between two boreholes, hence provide additional information on the nature of the deposit. Application of the presented method to the Voisey's Bay deposit allows improving the knowledge of the geological framework and generating grades models with realistic spatial variability.