Besim, Jen, Kristie, Mark, Victor (holding Jordie), Kristen and Kyle. Blacksburg; September, 2013

Mark Caddick

Mark Caddick

Mark is an assistant professor of geology, working on petrology of magmatic and metamorphic systems. His work is multi-disciplinary, with emphasis on unravelling tectonic histories by understanding preserved minerals and their geochemical signatures. He employs and develops methods for studying chemical equilibrium and disequilibrium in rocks – these aim to illustrate both the paths that rocks and melts take through the crust, and the duration over which they evolve. Mark is currently working in diverse settings from subduction zones to ultra-high temperature terranes – take a look at our research, resources and publications pages for more information.

Mark arrived at Virginia Tech in 2012. Before this he was a research associate at ETH, Zürich, a Ph.D. student at the University of Cambridge, and an undergraduate at the University of Bristol.

Mark:  Publications   CV   email me

Robert Tracy

Robert (Bob) Tracy is a professor of geology at Virginia Tech. Bob's current interests include (i) developing techniques for electron microprobe dating of monazites, especially targeted dating of thermal pulses and shearing events, (ii) tectonic interpretation of monazite dating, (iii) ultra-high temperature processes in contact metamorphism, particularly of aluminous xenoliths, (iv) imaging and interpretation of very fine-scale chemical zoning in metamorphic garnet, and (v) metamorphic and tectonic relationships of terranes in the Appalachians.

Before arriving at Virginia Tech in 1986, Bob was a Research Fellow at Harvard University then an Assistant and Associate Professor at Yale University. His B.A., M.S. and Ph.D. degrees were from Amherst College, Brown University and University of Massachusetts, respectively.

Post Docs & Visiting Professors

Besim is a post-doc who arrived in spring 2013 after a Ph.D. at Boston University. Prior to this, he gained B.A. and M.S. degrees from Boston University and University of Conneticut, respectively, and spent 6 years working as a research chemist in industry.

Besim specializes in coupling isotopic geochronology with petrological modeling to decipher rates of metamorphic processes. He is currently involved in projects examining systematics of garnet growth in both very low temperature settings (subduction zones) and at very high temperatures (granulite terranes).

Julie is a visiting scholar from Victoria University of Wellington, New Zealand. During her current sabbatical she has visited CSIRO Australian Resources Research Centre in Perth and the University of Wisconson-Madison, before coming to Virginia Tech.

Julie works on interpreting rock records of metamorphism, with emphasis on understanding pressure–temperature–time–deformation (P-T-t-d) paths, poly-metamorphism (effects, timing, tectonic causes), fluid flow and fluid/rock interaction in orogenic belts, and crustal-scale fault zones.

Graduate Students

Kirkland is a PhD student who recently joined the Metamorphic Processes Group for the Fall 2015 term. He previously earned his B.S. from the College of William & Mary.

Kirkland is broadly interested in understanding metamorphic processes at destructive plate boundaries. In particular, he is currently studying (i) the nature of synorogenic magmatism and its effects on the P-T-t paths of metamorphic rocks, and (ii) metamorphism during subduction in the western Alps. More information is available here.

Jen is a Ph.D. student who joined the Metamorphic Processes Group as a graduate student in Fall 2013, following her B.S. degree, also at Virginia Tech.

Jen is working on subduction zone metamorphic processes and timescales, focusing in particular on volatile production associated with high-pressure metamorphism on the Aegean islands of Sifnos and Syros.

Victor is a Ph.D. candidate who joined us in Fall 2012 from the University of Montana, where he completed his M.S.

Victor is working on hot and ultra-hot metamorphic rocks, using preserved chemical and textural features to infer the conditions and duration of their heating–cooling histories, and the tectonic mechanisms for such extreme crustal heat flux. He is currently comparing the evolutionary timescales of some of the oldest and youngest known granulite facies rocks.

Calvin is a Ph.D. student who joined us in Fall 2014 from the University of Massachusetts where he completed his M.S.

Calvin works with both the Metamorphic and Structural geology groups studying the geology of the Scottish Caledonides. His current work involves using monazite geochronology to place better time constraints on the thermal evolution of the Scandian orogenic wedge in the Northwestern Highlands of Scotland. Future garnet geochronology will compliment these efforts.


Emma is a Masters student who joined the Metamorphic Processes Group as a graduate student in Fall 2015, following her B.S. degree, also at Virginia Tech.

Emma works both with the both the Metamorphic and Sedimentary Geochemistry Group groups. Her project involves understanding the effect of contact metamorphism on sulfur and carbon bearing specices in sedimentary rocks.

Undergraduate Students

Hanna Brooks

Matthew Petroff

Hanna is an undergraduate student working with members of our group on a variety of projects associated with subduction zones. She began work on an independent research project in Fall 2013, focusing on fluid chemistries during subduction as preserved on the Greek island of Syros.

Matt is an undergraduate working with members of our group and the Sedimentary Geochemistry Group on a variety of projects associated with serpentine. He began work on a project examining carbon and sulfur isotope data of serpentinites from peridotite hosted hydrothermal systems in Summer 2014.

Honorary Members

Jordie (Petro Dog)

Jordie is a fieldwork enthusiast. In addition to running circles in snowfields, smelling wildflowers, and finding the most comfortable spot to rest his head, he has a spectacular nose for hunting out garnet-rich rocks. He is undoubtedly the fittest group member when it comes to working in rugged terrain.


Kyle Ashley

Kristie Dorfler

Kyle graduated with a PhD in Spring 2015. He worked on a variety of projects, investigating rock evolution in metamorphic and igneous terranes (with respect to P-T-t path, heating duration, fluid composition, mineral growth, and microstructural evolution). This work was coupled with investigations into deformation and fabric development. Much of his work focuses on quartz growth and deformation histories, and the calibration of innovative thermobarometer techniques. More information is available on our publications page.

Kyle is currently a Jackson School of Geosciences Distinguished Postdoctoral Fellow at the University of Texas at Austin.

Kristie graduated with a PhD in summer 2014. She studied partial melting and development of disequilibrium assemblages and textures in high-pressure & ultra-high temperature (up to 1200°C) aluminous xenoliths from the Cortlandt Complex, NY State. Image and chemical analyses and thermodynamic modeling were coupled to improve our understanding of rock/magma interaction and reactive xenolith preservation. More information is available on our publications page.

Kristie is currently a visiting assistant professor at Oberlin College, Ohio.

Kristen McCall

Ryan Ordnung

Kristen graduated with an M.S. degree in summer 2014 after work on quantifying some of the key controls on formation of metamorphic texture. Numerical models were used to simulate crystal growth in static or deforming rocks and understand how element mobility and thermodynamic driving forces couple to produce textural features in natural metamorphic rocks. More information is available on our publications page.

Following a summer internship with CONSOL Energy during her M.S., Kristen accepted an offer from ExxonMobil. She is now working as a geoscientist in Houston.

Ryan graduated with a B.S. in spring 2015. He worked with Esther on projects associated with the serpenization process. His independent research project focused on the mineralogical evolution of serpentinite veins in pyroxene grains from peridotites.

Ryan is currently working as a Junior Geologist for Groundwater and Environmental Services. He is also continuing to work with Esther on his undergraduate research project.

Esther Schwarzenbach


Esther is a petrologist and geochemist who works on serpentinization. She studies serpentinite’s petrology and micro-textures, tracing their evolving temperature and oxygen fugacity, and the origin of the interacting fluids. Sulfur isotopes (32S, 33S & 34S) allow her to fingerprint biogenic activity, demonstrating the extreme fluid conditions and temperatures that support microbial life.

Esther worked as a research scientist at Virginia Tech after receiving her doctorate at ETH Zurich, Switzerland. She is currently a research assistant in the Institute of Geological Sciences at Freie Universität Berlin.