Translating the mineral systems approach into an effective exploration targeting system

Abstract

Holistic mineral systems approaches are being increasingly adopted in the study of ore deposits but application in industry has been suboptimal, because of the lack of a conceptual framework to help translate the mineral system understanding to practical application. A four-step process is proposed for linking the conceptual mineral system with data available to support exploration targeting. These steps include translation from (1) critical processes of the mineral system, to (2) constituent processes of the mineral system, to (3) targeting elements reflected in geology, and (4) targeting criteria used to detect the targeting elements directly or by proxy. This translation process is illustrated using examples from komatiite-hosted Ni–Cu–PGE and orogenic Au mineral systems. Ranking of targets must be at the critical process level, rather than the current practice of mixing processes, elements and proxies. The significance of targeting elements and their mappable criteria changes as a function of the scale at which the critical processes operate and the availability of relevant geoscience datasets. This scale dependence is rarely recognised in current practice. Sources of uncertainty when translating the mineral system understanding into an effective exploration targeting system include: (1) resolution of a mappable criterion in a dataset, (2) how well the targeting criterion reflects the targeting element, (3) how well the targeting element reflects the critical process and (4) whether the process being mapped is critical for the genesis of a mineral deposit. The first three sources of uncertainty collectively are termed the representativeness of the targeting criteria (i.e., how representative is a mappable criterion of the constituent process for which it is a proxy). The last source of uncertainty reflects our lack of understanding of the processes that control mineralisation, and highlights areas for further research.