Pathways to high grade gold – 3D gradient mapping of mineral systems

Summary

The aim of the project was to use 3D mineral system mapping technologies to translate mineral zoning into thermo-chemical gradients that may be related to the transport and deposition of gold.

Mineral sensors to map gradients in activity of H2O, pH, redox (e activity) as well as temperature (energy) gradients are documented and the concept of zoned volato-thermal plumes as the productive architecture of Late Archean volato-thermal Au systems is introduced. The mineralogical/isotopic zoning of the Athena-Hamlet system, St Ives Gold Field is used to illustrate the concept. Preliminary integration/interpretation of mineral zoning/paragenetic/architectural constraints from the Kundana Camp suggests we may have identified a thermally-zoned Au system or at least a significant part thereof.

Gradient mapping within lithologically and structurally constrained 3D architectures, provides the basis for application to Au exploration. Targeting with mineral system concepts is a new and novel approach to adding value to brown field’s exploration strategies. The ability to identify and rapidly map complete systems should impact positively on both brown-fields and green-fields exploration.

Keywords: 3D mineral-system mapping, chemical gradients, mineral sensors, volato-thermal systems