From Melting Dynamics to Medical Diagnostics: Studies in Geochemical Kinetics

Citation

Miaou, Emily Yishiuan (2025) From Melting Dynamics to Medical Diagnostics: Studies in Geochemical Kinetics. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/ck82-t059. https://resolver.caltech.edu/CaltechTHESIS:05162025-025853405

Abstract

This thesis investigates geochemical kinetics across different subfields, from isotope metallomics in the human body to melting dynamics in igneous petrology. Chapters II and III explore the chemical complexities of rapid mineral melting in igneous systems. An experimental-computational approach is used, with the experiments providing data that help calibrate the numerical model. This integrated strategy contributes to a comprehensive understanding of the kinetics of melting that could not be captured by either method alone. Chapter II outlines the experimental work, which includes both equilibrium and kinetic melting experiments performed on the ubiquitous igneous mineral series plagioclase. The kinetic experiments are designed to deliberately access a parameter space of disequilibrium behaviors rarely studied experimentally yet likely to be relevant in various natural settings where systems evolve too quickly to follow the predictions of equilibrium theory. Quantitative and qualitative analyses of the recovered experimental products allow us to observe unique textures and chemical gradients that arise from the interplay of thermal and chemical diffusion within the phases, coupled with phase boundary motion and associated surface reactions. Chapter III details the theory and computational methods used to develop a numerical model that describes chemical evolution of melt and crystal phases during two-component melting. Novel application of thermodynamic data is used to describe chemical behavior at the phase boundary, allowing for departure from traditional equilibrium assumptions. Results of the model bring us one step closer to the ultimate goal of understanding disequilibrium in multicomponent rock systems. Chapter IV investigates the kinetics of stable isotopes in biomedicine. Box modeling was used to simulate copper (Cu) stable isotope dynamics in the human body, allowing us to quantify the possible effects of various health conditions (e.g., cancer, liver disease) on isotopic compositions throughout different organs. In turn, we determine whether Cu isotopes can act as diagnostic or prognostic markers for certain diseases using detection by modern mass spectrometry and provide recommendations on their potential uses in the medical field.

Thesis Files