Using zircon geochemistry to map alteration in the Gawler Craton, South Australia

Summary

Zircon is a refractory mineral that is able to crystallize within hydrothermal, igneous and metamorphic environments, resulting in extreme variability in its external morphology, internal textures and chemistry. The chemistry of zircon is sensitive to its source rock type and crystallisation environment. Zircon has a tendency to incorporate a range of minor and trace elements, largely determined by its crystal structure and changes in temperature, pressure and composition. Internal textures of zircon can be used to indicate the type of crystallisation environment, as well as the environment(s) to which it was subjected following crystallisation. Given the complexity of zircon textures and the uncertainty associated with interpreting isotopic ages, trace element analysis is becoming widely applied as another line of evidence for more confident petrogenic interpretation.

Here we present geochemical and morphological data from zircon from the Gawler Craton, South Australia. This area preserves a complex geological history dating back to the late Archean and preserves multiple igneous units that each have their own unique geochemical characteristics and are associated with iron oxide-copper-gold mineralisation. We show that zircon will preserve chemistry reflective of its host rock, and possibly of alteration associated with mineralisation.

• Zircon
• Geochemistry
• Gawler Craton