The existence of molten rock within the Earth is an idea that has fascinated humanity for millennia, and understanding the origins and the evolution of magmas is a subject at the core of the geological sciences. Even though magmas are present only in minor abundances in the Earth at any given point in time, melting and solidification greatly affect the way the Earth works, being responsible for the generation of the oceanic and continental crusts, and for permanent changes in the Earth’s mantle. Given that magma bodies are the sites of differentiation of magmas, understanding magma bodies is in fact an integral part of our attempt to understand the physical and chemical differentiation of the Earth. On more practical grounds, magma bodies in the subsurface are feeders to volcanic eruptions, and one of the potential outcomes of the study of the evolution of magmatic systems is an improved ability to predict hazardous volcanic eruptions.
The fundamental goal of my research is to better understand the evolution of magma bodies, in particular silica-rich magma bodies. I aim to unravel the processes that shape the evolution of these magma bodies, and to constrain their physical state at various stages of their evolution. I pay particular attention to the stages leading to eruption, and to the conditions that make eruptions possible, likely, or inevitable. I am especially interested in combining the volcanic and plutonic rock records in this effort.
The main challenge in studying the evolution of magma bodies is our inability to witness the relevant magmatic processes occurring at depth and on timescales orders of magnitude longer than our lifetimes. Given these constraints, we rely on the study of rocks to understand the evolution of magmas. I pursue these problems by exploring the detailed record of magmatic processes preserved in the microscopic scales (e.g. minerals, glass, vesicles), and I use these data to inform our understanding of processes on the crustal scale (e.g. magma evolution, decompression, eruption). I study two facets of the rock record. On one hand, I use the physical distribution of crystals and vesicles, their sizes and contact relations–what we call textures. On the other hand, I use mineral compositions and compositional variations (i.e. zoning) to investigate the internal histories of crystals, and also to correlate this textural evolution with the chemical evolution. What emerges is a clearer picture of the spatio-temporal evolution of magma bodies, the processes that shape their evolution, and the conditions that lead to or prevent eruptions.
“Evolution of magma bodies that feed supereruptions”
Collaborators: Darren Gravley (Canterbury, New Zealand); Ayla Pamukcu (WHOI); Mark Ghiorso (OFM Research); Calvin Miller (Vanderbilt); Chad Deering (Michigan Tech); Steve Sutton, Mark Rivers (Chicago)
Students & Post-docs: Lydia Harmon*, Genna Chiaro*, Blake Wallrich*, Brandt Gibson*, Brad Pitcher†, Liam Kelly*
Evolution of magma bodies that feed supereruptions. Hundreds to thousands of cubic kilometers of magma are ejected to the surface in a matter of weeks to months during a supereruption. We aim to understand the timescales of evolution, the architecture of the crust in the moments leading to supereruptions, and the processes that shape their evolution.
“Towards a record of volcanic eruptions from plutonic rocks”
Collaborators: Bob Wiebe (UC Davis); Jonathan Miller (San Jose State), Calvin Miller (Vanderbilt)
Students & Post-docs: Susanne Seitz†
Granitic plutons preserve a complex record of magma crystallization over extended periods of time. We use zoning in feldspars to better understand the histories of magma injection and eruption that shape the evolution of magmas at the subsurface.
“Phase equilibrium modeling of magmatic systems”
Collaborator: Mark Ghiorso (OFM Research)
Students & Post-docs: Liam Kelly*
We develop thermodynamic tools that can be used for calculation of equilibrium phase assemblages and the evolution of magmas, particularly focused on applications for silicic magmas under crustal conditions.
“Trace elements as constraints for the evolution of magma bodies”
Collaborators: Calvin Miller, Lily Claiborne (Vanderbilt), Mark Ghiorso (OFM Research)
Students & Post-docs: Blake Wallrich*
We are currently gathering data on partition coefficients between mineral and melt during magmatic crystallization to better understand the processes by which magmas are created and modified within the Earth’s crust.
“Volcanic styles associate with silicic magmas of the Paraná Province, South Brazil”
Collaborators: Darren Gravley, (Canterbury), Edenilson Nascimento (UFPR, Brazil)
Students & Post-docs: Lydia Harmon*, Samuel Heagney§
We are developing criteria to distinguish and characterize volcanic deposits that are extensively welded and rheomorphically deformed, to understand the distribution of volcanic centers and the sequence of volcanic events associated with opening of the South Atlantic in South Brazil.