Experimental constraints on basalt-rhyolite mixing dynamics in a caldera-forming eruption

Volcanic eruptions commonly involve several magma batches with distinct compositions that meet and mix during or shortly prior to eruption. In some cases, this mixing process can prime or trigger eruptions, as ascending hot and gas-rich magmas can remobilise and mix with cooler magmas stalled at shallower depths and destabilise the magmatic system. We have conducted field and geochemical studies on deposits from the Halarau?ur eruption (Krafla volcano, Iceland), a very large eruption that provides physical and chemical evidence for mixing of two discrete magmas. To assess any role this mixing process may have played in priming or triggering this eruption, it is crucial to constrain the timescale over which mixing occurred. We will use a recently developed, cutting-edge experimental apparatus at the University of Perugia, designed to replicate the dynamics of magma mixing under natural conditions, to perform a time-series of chaotic mixing experiments using natural end-member samples from the Halarau?ur deposits. By examining the compositional evolution of the hybrid (mixed) magma through time in our experiments, we will constrain the timescale of magma mixing during/prior to the Halarau?ur eruption […]

Faculty Supervisor:

John Stix

Student:

Partner:

University of Perugia

Discipline:

Earth science

Sector:

Sustainability & the Environment; Environmental Science and Technology

University:

McGill University

Program: