School of Earth Sciences - Centre for Exploration Targeting
Centre for Exploration Targeting (CET)
School of Earth Sciences
The University of Western Australia (M006)
35 Stirling Highway
CRAWLEY WA 6009
Research Output / Publications
Originally trained as a chemist, I switched to geology for my PhD (University of Maryland, College Park) and became fascinated with the tiny pockets of fluid (fluid inclusions) that are found in minerals in virtually every hydrothermal environment on Earth (and beyond actually). These inclusions are often ignored as “holes” or “blemishes” to be avoided, but actually provide us a window into the rapidly changing hydrothermal environments of short and long-lived geologic systems. With recent micro-analytical advancements, they can even be quantified to nearly the same precision as rock and mineral samples. My research is focused on using these inclusions to understand the interplay between hydrothermal ore deposits, geothermal reservoirs, and volcanic degassing.
My long-term research goal is to build much stronger links between interpretation of hydrothermal alteration, ore geology, geothermal reservoir modelling, and volcanic hazard monitoring. Each of these disciplines captures part of the “mineral-hydrothermal” system but all can benefit from a more synergistic view of the complex and rapidly changing hydrothermal fluids involved. Connecting magmatic fluid evolution across these disciplines is also vital to a true “source to surface” understanding of hydrothermal fluids and improving our treatment of extreme fluids in our mineral systems models and distal exploration programs for hydrothermal ore deposits.
I completed my PhD in 2012 examining the ability of high-temperature magmatic fluids to scavenge and transport ore metals. My research had since expanded to understand the interface between high-temperature fluids and minerals/melts “from source to surface”. This includes understanding the generation of hydrous melts, various processes that control volatile degassing from magmas, fluid-rock interactions at both the magmatic and hydrothermal stage, and the deposition and fingerprint of ore mineral precipitation. I examine both natural and synthetic systems in order to understand these processes and have pioneered a number of experimental and analytical techniques to improve how we can characterize fluids in these extreme environments. My research utilizes a mineral systems approach that is aimed at improving our understanding of extreme (e.g. high-temperature, hypersaline) hydrothermal fluids across scales in order to improve our ability to vector towards high-grade ore within deposits, model large hydrothermal and geothermal fluid reservoirs, and evaluate the arc-scale processes that generate metalliferous magmatic fluids.
I have been working at the University of Bristol collaboratively with BHP for 8 years on hydrothermal ore deposit research projects as well as broader industry collaborative research funded by NERC in the UK. At the CET I am leading a project funded by BHP on high-grade Cu-Au porphyry ore formation as part of a consortium group which includes other researchers at UWA (Dr. Marco Fiorentini, Dr. Steffen Hagemann, Dr. Tony Kemp) and Curtin (Dr. Katy Evans) as well as partners at the University of Bristol, the University of Oxford, Imperial College London and the Natural History Museum in London. Our project is focused on refining the mineral systems models for porphyry deposits in order to improve our ability to find not just ore, but high-grade ore that will be required to satisfy the demands of a transition to a greener energy economy. As part of my goal of developing a holistic picture of magmatic fluids, I am also very keen to develop new collaborative research opportunities. I currently work with the Geologic Survey of Japan (AIST), the BGS, the Montserrat Volcano Observatory, and academic partners in the USA, Canada, UK, Iceland, Russia, France, and Switzerland.
Unfortunately, the magmatic-hydrothermal fluids that are critical to understanding ore formation, geothermal power generation, and volcanic degassing are unquenchable and unrecoverable to atmospheric pressure and temperature. My foremost expertise lies in designing and implementing new experimental and analytical techniques for creating synthetic hydrothermal fluid reservoirs and directly quantifying mineral-melt-fluid assemblages. In the laboratory, I utilize high-temperature (400-1200 oC) vessels pressurized to hundreds or thousands of times atmospheric pressure to create synthetic mixtures of fluids, minerals, and melts. Upon rapid cooling the minerals and melts quench to stable phases, but the fluid does not. However, I have several techniques to trap equilibrium samples of these fluids as small bubbles or “fluid inclusions” within minerals that provide us an opportunity to accurately quantify the properties of that fluid. This can include major volatile chemistry (e.g. H2O-CO2-H2S-SO2-CH4), major element (e.g. NaCl-KCl-CaCl2-FeCl2) and trace element data (e.g. Cu, Au, Ag, Li, Mo, W, REEs, etc.). These same kinds of fluid inclusions occur in natural hydrothermal systems and with careful interpretation can provide the same kinds of compositional data along with the pressure, temperature, or even oxidation environment in the system. I have used these techniques to study metal transport, model trans-crustal magmatic degassing, simulate and quantify high-temperature hypothermal alteration, and characterize modern and ancient supercritical hypersaline magmatic fluid reservoirs.