Location
University of Nevada Las Vegas, Student Union Ball Room
Start Date
6-8-2008 9:00 AM
End Date
6-8-2008 12:00 PM
Description
We are studying how the mineral fayalite deforms under stress while it is subject to high pressures and temperatures. Specifically, we are analyzing x-ray diffraction spectra obtained from experiments with the D-DIA apparatus at Brookhaven national labs. By fitting peaks to the diffraction spectra, we can calculate the spacing between lattice planes of fayalite and so we can observe how this spacing changes over time as the crystal structure deforms We hope to show that this deformation can be modeled using an Elastic Plastic Self Consistent model. In such a model, the material is treated as a cluster of independently oriented grains. When stress is applied to the material, deformation takes place because the lattice planes can slip by each other. A variety of slip systems are used to model the different ways these planes can move. The model allows us to calculate the aggregate properties of the material from the microscopic properties of the individual grains. The goal of our project was to fit an Elastic Plastic Self Consistent (EPSC) model to experimental data on the deformation of the mineral fayalite (Fe2SiO4) which is the iron end member of olivine. In the past, Professor Burnley has successfully fit an EPSC model to experimental data on the deformation of quartz. If an EPSC model could be fit to data on fayalite, it would further support the use of these models to study the plastic deformation of minerals. Modeling the deformation of fayalite is of particular interest because olivine is an important component of the Earth’s mantle and studying how it deforms at high temperatures and pressures can help us understand how the mantle moves over time. The first step in our project was to analyze the experimental data set. We also explored some of the parameter space of the EPSC model before trying to fit the model to the data. Unfortunately, our attempts to fit the model to the experimental data have been unsuccessful, and this suggests that there may be another deformation mechanism involved in the deformation of fayalite.
Keywords
Crystalline structures; Deformation; Elastic plastic self consistent (EPSC) model; Fayalite; High temperatures; High pressures; Mantle; Minerals
Disciplines
Geophysics and Seismology | Mineral Physics
Language
English
Modeling the deformation of Fayalite
University of Nevada Las Vegas, Student Union Ball Room
We are studying how the mineral fayalite deforms under stress while it is subject to high pressures and temperatures. Specifically, we are analyzing x-ray diffraction spectra obtained from experiments with the D-DIA apparatus at Brookhaven national labs. By fitting peaks to the diffraction spectra, we can calculate the spacing between lattice planes of fayalite and so we can observe how this spacing changes over time as the crystal structure deforms We hope to show that this deformation can be modeled using an Elastic Plastic Self Consistent model. In such a model, the material is treated as a cluster of independently oriented grains. When stress is applied to the material, deformation takes place because the lattice planes can slip by each other. A variety of slip systems are used to model the different ways these planes can move. The model allows us to calculate the aggregate properties of the material from the microscopic properties of the individual grains. The goal of our project was to fit an Elastic Plastic Self Consistent (EPSC) model to experimental data on the deformation of the mineral fayalite (Fe2SiO4) which is the iron end member of olivine. In the past, Professor Burnley has successfully fit an EPSC model to experimental data on the deformation of quartz. If an EPSC model could be fit to data on fayalite, it would further support the use of these models to study the plastic deformation of minerals. Modeling the deformation of fayalite is of particular interest because olivine is an important component of the Earth’s mantle and studying how it deforms at high temperatures and pressures can help us understand how the mantle moves over time. The first step in our project was to analyze the experimental data set. We also explored some of the parameter space of the EPSC model before trying to fit the model to the data. Unfortunately, our attempts to fit the model to the experimental data have been unsuccessful, and this suggests that there may be another deformation mechanism involved in the deformation of fayalite.
Comments
Abstract & poster