Eric D KellyPostdoctoral Fellow, Department of Geological Sciences
Eric is a metamorphic petrologist who investigates fundamental problems of metamorphism. He applies that knowledge to determine the conditions of metamorphism and the tectonic processes that cause metamorphism. He collects samples in the field to understand the structural and tectonic context of the samples and analyzes them with petrographic, analytical, and numerical techniques.
He investigates metamorphic problems from the non-traditional perspective of crystallization occurring under chemical disequilibrium. Traditional methods in metamorphic petrology are tied to the assumption that minerals approach chemical equilibrium during metamorphism. However, increasing evidence invalidates that assumption, and if equilibrium-based techniques are applied to disequilibrium mineral assemblages, the interpretations of geologic history may be erroneous. Departures from equilibrium have profound effects on estimates of pressure, temperature, chemical composition, and time extracted from metamorphic rocks, and his work focuses on quantifying kinetic factors of crystallization to determine the departures from equilibrium that impact interpretations of geologic history.
Currently, Eric's research is on determining intracrystalline diffusion rates of petrologically and geochronologically important trace elements in garnet. Garnet is one of the most important metamorphic minerals because of its wide P-T-X stability range and ability to record and preserve chemical zoning acquired deep in the crust. Trace elements (e.g., REEs, Y, Li) in garnet have the potential to reveal the timing and conditions of metamorphism through careful analysis of zoning and well-constrained intracrystalline diffusion rates. However, trace element diffusion rates in natural garnet are poorly constrained at low temperatures (<700 degrees C). Eric is determining these intracrystalline diffusion rates in natural garnets at low temperatures through analytical (EPMA, LA-ICPMS, nano-SIMS) and numerical techniques.
Areas of Expertise
Metamorphic petrology; mineralogy; geochronology; thermodynamics; mineral chemical zoning; disequilibrium crystallization; crystallization kinetics including nucleation rates, diffusion rates, and interfacial energies of crystal nucleation; numerical models of metamorphic processes used to extract fundamental constraints on crystallization and geologic history; P-T-t path construction
Glenn and Martha Vargas Endowed Presidential Scholarship - The University of Texas at Austin (2010)
Thomas R. Banks Memorial Scholarship - The University of Texas at Austin (2007)
Robert H. Cuyler Endowed Presidential Scholarship - The University of Texas at Austin (2007)
The Montgomery Prize - Northern Arizona University (2004)
Outstanding Teacher Award - Northern Arizona University (2004)
Geology Department Alumni Grant - Northern Arizona University (2003)
Abandoning the equilibrium assumption: Effects of disequilibrium on metamorphic interpretations, Baylor University, Waco, Texas (2012)
Implications of garnet resorption for the Lu-Hf garnet geochronometer: An example from the contact aureole of the Makhavinekh Lake Pluton, Labrador, Colby College, Waterville, Maine (2011)