Application of geochemical zonality coefficients in mineral prospectivity mapping

Abstract

Indices of geochemical zonality ( Vz) of multielements around mineral deposits and their spatial associations with particular geological, geochemical, and structural factors are critical aspects that must be considered in mineral exploration. Values of Vz indices allow distinction between sub-ore and supra-ore anomalies, which are associated with outcropping and blind deposits, respectively. In this paper, we used a map of a Vz index (Zn⁎Pb/Cu*Ag) in weights-of-evidence analysis of regional-scale prospectivity for porphyry–Cu deposits in the area covered by 1:100,000 scale map sheet of Jebal-Barez (Kerman province, southern Iran). For comparison, we used a Cu map instead of the Vz map in the weights-of-evidence (WofE) analysis. The Vz-in-WofE prospectivity model outperforms the Cu-in-WofE prospectivity model. In fact, prior to writing this paper, blind porphyry–Cu mineralization was intersected at depth by borehole exploration in a high prospectivity zone delineated by the Vz-in-WofE model. The results demonstrate the usefulness of the Vz-in-WofE for regional-scale targeting of blind mineral deposits.