Clara Waelkens

PhD student
McGill University

In September 2015, I started a PhD at McGill University, under the supervision of Professor John Stix. The project concerns magmatic processes in large silicic calderas, and more specifically focusing on the cataclysmic Bandelier eruptions that took place in Valles Caldera, in the Jemez Mountains of New Mexico, between 1.1 and 1.6 million years ago. One part of my research focuses on establishing how the volatiles in the magma chamber – particularly H2O and CO2 – evolved before the super-eruptions and as the magma reservoir was re-establishing itself after eruption. H2O and CO2 are relevant to study, as their concentration in a magma will influence the magma’s behaviour. In addition, the accumulation of volatile elements in a magma chamber can contribute to triggering an eruption, as it leads to overpressure in the magma chamber. A second aspect is to look at how the Bandelier magma was related to lava domes and flows Tschicoma Formation, erupted mainly between 3 and 5 million years ago in the Jemez Mountains, and exposed now north and east of Valles Caldera. Through major, trace element and isotopic analyses, I am looking at how the different domes of the Tschicoma Formation are related – whether they were all erupted from a same batch of magma, or underwent separate, distinct evolution trends – and how the Tschicoma magma is related to the Bandelier magma. Being part of the MAGNET network has greatly contributed to my evolution as a scientist. The many workshops, seminars and courses introduced me to many different aspects of geochemistry, and particularly to their application in the industry. It has been an invaluable experience, which I am sure will have contributed to my future career in sciences.