Jon Blundy Lecture

15 May 2019



From Ores to Ash: the Inner Workings of Hazardous Volcanoes

A public lecture by Jon Blundy, Professor of Petrology, University of Bristol and 2019 UWA Robert and Maude Gledden Senior Visiting Fellow.

Volcanoes are best known for their potential to wreak hazard, through catastrophic eruptions and climate-changing gas emissions. However, volcanoes also furnish humankind with considerable bounty, in the form of fertile volcanic soils and metal ore deposits. Any geological account of volcanoes must explain the tendency of some magma systems to evolve towards eruptions, while others solidify underground, sometimes forming ore deposits. Can a single model explain both outcomes?

In this public lecture Professor Blundy will discuss how our concept of volcanic systems has evolved in the light of recent geophysical and geochemical studies from the classic magma chamber concept, so beloved of textbooks, to a more nuanced system of partially molten rock that straddles the entire crust of the Earth. Professor Blundy will explain how such ‘transcrustal magma systems” can account for apparent dichotomy of outcome (“ashes or ores”) and what such systems mean for the monitoring of restless volcanoes. He will show that the build-up to very large eruptions may be much shorter than previously assumed, while some of the world’s largest copper ore deposits may form in the geological blink of an eye. The talk will draw on examples of Professor Blundy’s fieldwork in some of the world’s most hazardous volcanic regions, including the Andes, the Lesser Antilles, and the Cascades Range of the western USA.

Jon Blundy is an igneous petrologist, with interest in all things magmatic, from magma generation in the crust and mantle to trace element geochemistry, active volcanism and ore formation. He approaches these topics through a combination of field observations, thermodynamics, geochemical analysis, and high pressure and temperature experiments. He is Professor of Petrology at the University of Bristol (UK), where he has been since 1989. He has held visiting positions at the universities of Oregon and Nagoya (Japan), California Institute of Technology and, currently, UWA, where he is a Robert and Maude Gledden Visiting Fellow. He has published some 200 articles in the scientific literature and received a number of awards for his research, including the Ted Ringwood Medal of the European Association of Geochemistry (2016), and the Bigsby (2005) and Murchison (2016) Medals of the Geological Society. He was elected Fellow of the Royal Society in 2008.