Phase relations and thermodynamic properties of spinelloid phases in the system Mg_1tn2SiO_1tn4-Fe_1tn2SiO_1tn4-Fe_1tn3O_1tn4 at high temperatures and pressures [Elektronische Ressource] / presented by Mario Koch

Phase Relations and Thermodynamic Properties of SpinelloidPhases in the System Mg SiO –Fe SiO –Fe O at high2 4 2 4 3 4Temperatures and PressuresDissertationsubmitted to theCombined Faculties for Natural Sciences and Mathematicsof the Ruperto-Carola University, Heidelberg, Germanyfor the degree ofDoctor of Natural Sciencespresented byDiplom-Mineraloge Mario Kochborn in Ludwigshafen/PfalzMay 2003Referees: Prof. Alan B. Woodland, Ph.D.Prof. Dr. Rainer AltherrOral examination: June 27th, 2003Table of contentsTable of contents1. Introduction1.1. Mantle mineralogy and seismic discontinuities 11.2. Spinelloids 43+1.3. Fe in the Earth's mantle 61.4. Goals of this study 72. Experimental Methods2.1. Starting material synthesis 92.2. High pressure experiments 102.2.1. Multianvil apparatus 102.2.2. Belt apparatus 143. Analytical Methods3.1. Electron microprobe and scanning electron microscope 173.2. X-ray powder diffraction 184. Results4.1. Chemical data 214.1.1. Phase relations 214.1.2. Stability of spinelloid III and wadsleyite 334.1.3. Stability of spinel 334.1.4. Occurrence of additional phases 334.2. Structural data 344.2.1. Unit-cell parameters and cell volumes of spinel solid solutions 364.2.2. Unit-cell parameters and cell volumes of the spinelloids 374.2.3. Olivine 385. Discussion5.1. Phase relations 415.1.1. Spinelloids and spinel 415.1.2. Additional phases 412+5.1.3. Equilibrium and Mg-Fe partitioning 425.2.