Application of phase-field simulation of solidification and texture evolution to diffusion chronometry

• Applicant: Dr. Julia Kundin
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 405665352

The aim of the project is to develop a quantitative understanding of the growth mechanisms and texture formation during the growth and dissolution of crystals in melt bearing systems. This is of particular interest for the applications of Diffusion Chronometry to magmatic systems, where the process of textural maturation involving growth and dissolution of crystals and associated changes in crystal shapes lead to modification of diffusion profiles (and may ultimately set an upper limit to timescales accessible by diffusion chronometry i.e. timescales of crystal dissolution). The phase-field modeling method, which is an efficient, thermodynamically consistent tool for modeling complex diffusion and growth phenomena, is being used for this. In the first cycle of funding, a formulation that allows anisotropic crystal forms such as those of common mineral like olivine, plagioclase and diopside to be modeled was developed and tested in model binary systems. Several general implications for the study of igneous rocks emerged already from those simple models. In this next phase, the developments will be extended to systems with multicomponent melts with realistic compositions (and hence temperatures) that are applicable to natural systems, and to the handling of solid-dominated partially molten systems (i.e. mush zones, where many solid- solid grain contacts need to be modeled). Some experiments will be carried out test and benchmark the numerical models.

• DFG Programme: Research Units
• Subproject of: FOR 2881: Diffusion Chronometry of magmatic systems
• International Connection: United Kingdom
• Cooperation Partner: Dr. Katharina Marquardt