『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 significant 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.
Keywords: Gold; Nickel; Mineral systems; Exploration; Targeting』
1. Introduction
2. Mineral systems
3. Mineral systems to exploration targeting systems
3.1. Generating targeting models
3.2.Target ranking
4. Representativeness and sources of uncertainty
5. Scale dependence of targeting criteria
6. Summary and conclusions
Acknowledgements
References