My research focusses on two mains areas of activity.  The first uses the mineralogical and geochronological record of metamorphic rocks to unravel tectonic histories and tectonic behaviour of crustal systems in space and time.  The bulk of the continental and oceanic crust has been processed by metamorphism.  These metamorphic mineral assemblages record the thermal and mechanical processes that form and/or modify the Earth’s crust.  Metamorphic rocks effectively encompass the entire duration of the Earth’s rock record, so they encode the rise and fall of continents and mountain belts, the birth and death of oceans and the evolution of the thermal state of the crust through Earth’s history.

The second main area of research is on mineral exploration, particularly copper, in Australia.  Copper is unambiguously the most critical metal in the transition to a lower carbon economy.  The bulk of the world’s copper endowment is contained in porphyry systems that developed in thick magmatic arcs, and exploration strategies in such systems are well understood.  However, Australia is notably lacking in thick arc systems.  Instead, Australia’s copper endowment is principally contained in tectonically ambiguous iron-oxide-copper-gold and diverse epi-genetic replacement systems in the Gawler Craton and Mount Isa regions.  Consequently, copper exploration in Australia is more complex than in young arc-dominant systems.  Our research is focussed on improving the age constraints on copper mineralisation to better understand the tectonic environment of ore formation in order to identify new areas of copper prospectivity.

In addition to these foci, I also work on the geochronological and mineralogical record of the early Solar System using materials derived from pallasite and mesosideritic meteorites.

Examples of current projects

Garnet speed dating to resolve tectonic histories.  Traditionally, the age and duration of high temperature tectonic events has been generally constrained by the age of zircon and monazite.  However, the age relationship between these minerals and minerals in the same rock used to constrained depths and temperature has to be inferred, rather than proven.  Consequently, there is no particular reason why the age of zircon and monazite is the age of the metamorphic mineral assemblage.  Using a new dating method we have developed for dating garnet, our research has shown that zircon and monazite ages may be drastically different to the age of high temperature metamorphism, requiring conventional tectonic histories to be rewritten.

Interrogating the thermal record of supercontinent formation.  Ultrahigh-temperature (UHT) metamorphism represents the extreme limit of temperatures that are regionally attainable in the Earth’s crust and is typically assumed to be linked to supercontinent formation.  However, a common feature of UHT crust is UHT mineral assemblages are volumetrically minor.  Instead, the bulk of the crust is composed of apparently lower temperature rocks.  This common relationship calls into the question to what extent UHT mineral assemblages represent the ambient thermal state of deep supercontinental crust.

Behaviour of material in subduction channels.  Subduction channels are dynamic systems within which material is simultaneously subducted and exhumed.  This two-way flow leads to complex interplays where material can be partially exhumed and then resubducted.  The time scales of these processes likely vary depending on whether the subducted material is oceanic or continental and are poorly understood.  Our research is focussed on determining the duration of matertial interactions in subduction channel and their implications for the size of ancient and now consumed oceans.

New horizons for copper exploration:  Large-scale copper mineralisation in southern Australia (most notably Olympic Dam, Carrapeteena, Prominent Hill) occurred 1580 million years ago.  However our recent work has identified a younger and unrelated copper system in the northeasten Gawler Craton that formed more than 100 million years later.  Our present work is focussed on determining the spatial and temporal distribution of this newly discovered copper system to provide a better framework for greenfields mineral exploration.

Projects for Honours and PhD available in 2024 include

1. Taking the temperature of the deep Gondwanan crust.
2. The tectonic significance of ultra-high temperature metamorphism in southern Australia.  
3. What do hot and cold eclogites in eastern Australia tell us about subduction zone dynamics?
4. The new copper corridor, linking southern and northern Australia to unearth new opportunities for mineral exploration.