Choice of a methodological approach for the estimation of recoverable resources with uranium deposits in central Jordan

International audienceChoosing a resource estimation approach for uranium deposits central Jordan needs to consider various issues; the particular geological context of these deposits, the varying degree of reliability of input data and the level of selectivity that can be reasonably envisaged at a production stage. These issues make this resource estimation challenging from a geostatistical perspective. Here, we provide details of the approach used during resource estimation for the surficial part of uranium deposits in central Jordan; as a more standard approach has been applied to the deeper parts of these deposits. The workflow is as follows: (i) Interpolation of the geometry of the mineralised formation. Kriging with external drift is applied to model hangingwall and footwall surfaces. (ii) Estimation of global resources by 2D estimation of layer thicknesses and uranium accumulation using channel samples within delineated areas. (iii) Accounting for vertical selectivity and development of grade tonnage curves using uniform conditioning (UC) followed by localised post-processing (called LUC) delivering, a 3D block model at the selective mining unit support scale. A description of the UC/LUC approach and the adaptations made in order to account for the variable thickness is presented in this paper. This approach involves performing UC on each panel in turn with a thickness varying from panel to panel. This leads to a specific change of support coefficients for each panel. The illustrations of this approach are taken from one specific zone within the Central Jordan deposits. © 2015 Institute of Materials, Minerals and Mining and The AusIMM