Speaker
Description
Diffusion chronometry is an important tool in understanding various aspects of geological processes, e.g., processes in magma reservoirs [1]. However, the timescales which can be accessed by diffusion chronometry are restricted by recrystallization. While the coupling of mechanical and chemical processes has not been explored in a quantitative framework yet, it has been shown in both experimental [2] and field observations [3].
In this presentation we expand on the model introduced by Haddenhorst et al. [4] to describe the evolution of olivine crystals surrounded by a melt. Whilst the original model was intended to be used to describe the evolution of magnesium-based forsterite crystals exchanging iron as a fayalite component, thanks to its general nature, the model can be used to describe the behavior of varying crystals, which are present in volcanic eruptive products under the influence of any diffusing component.
Furthermore, the existing model is expanded by the introduction of a phase field approach and the inclusion of heat conduction. As the original model was restricted to idealized spherical crystals, the phase field approach enables us to simulate olivine crystals of arbitrary shapes.
We discuss the introduction of the phase-field model and present initial results.
References:
[1]: Chakraborty, S., \& Dohmen, R. (2022). Diffusion chronometry of volcanic rocks: looking backward and forward. Bulletin of Volcanology, 84 (6), 57.
Retrieved from https://doi.org/10.1007/s00445-022-01565-5
[2]: Nachlas, W., \& Hirth, G. (2015). Experimental constraints on the role of dynamic recrystallization on resetting the ti-in-quartz thermobarometer. Journal of Geophysical Research: Solid Earth, 120 (12), 8120–8137.
[3]: Bestmann, M., Pennacchioni, G., Grasemann, B., Huet, B., Jones, M. W. M., \& Kewish, C. M. (2021). Influence of deformation and fluids on ti exchange in natural quartz. Journal of Geophysical Research: Solid Earth, 126 (12), e2021JB022548. Retrieved from https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021JB022548
[4]: Haddenhorst, H. H., Chakraborty, S., \& Hackl, K. (2023). A model for the evolution size and composition of olivine crystals. Proceedings in Applied Mathematics and Mechanics, 00, e202300081. https://doi.org/10.1002/pamm.202300081
