A Study on Post-Shock Pressure?Temperature Conditions and Feldspar Amorphization Mechanisms in Meteorites Using Feldspar and Silica

목차 (Table of Contents)

• Chapter 1. Introduction 1
• 1.1. Importance of the study for Shock metamorphism of silicate minerals 2
• 1.2. Contents of thesis 6
• REFERENCES 8
• Chapter 2. Chemical and structural evidence for melt-induced amorphization of alkali feldspar in lunar meteorite DEW 12007: insight into shock amorphization mechanisms 12
• ABSTRACT 12
• 2.1. Introduction 13
• 2.2. Materials and Methods 15
• 2.2.1. Samples 15
• 2.2.2. Analytical methods 16
• 2.3. Results 18
• 2.3.1. Petrography of alkali feldspar in the granophyre clast 18
• 2.3.2. Crystallinity of alkali feldspar: Raman spectroscopy 20
• 2.3.3. Chemical composition of alkali feldspar: relationship between the crystallinity and the chemical composition in the partial amorphization process 22
• 2.4. Discussion 26
• 2.4.1. Chemical evidence of melt-quenched amorphous alkali feldspar 26
• 2.4.2. Application to other meteorites: feldspar in ordinary chondrites (L6) 28
• 2.4.3. Why shock-melted feldspar follows low-pressure phase relations 29
• 2.4.4. Diagnostics for distinguishing feldspar amorphization mechanisms 30
• 2.5. Conclusion 31
• APPENDIX 33
• 2A-1. Estimation of crystallinity using Raman spectra 33
• 2A-2. Raman and EPMA analysis point 36
• 2A-3. Texture observations by polarized light microscopy and BSE imaging 38
• 2A-4. Raman and EPMA analysis of feldspar in EET 13004 40
• 2A-5. EPMA results 41
• REFERENCES 43
• Chapter 3. Structural and compositional variations of feldspar in an ordinary chondrite induced by shock metamorphism 49
• ABSTRACT 49
• 3.1. Introduction 50
• 3.2. Materials and Methods 52
• 3.2.1. Samples 52
• 3.2.2. Analytical methods 53
• 3.3. Results 54
• 3.3.1. Observations under polarized-light microscope and backscattered electron imaging 54
• 3.3.2. Identification of crystalline and amorphous domains using Raman spectroscopy 56
• 3.3.3. Mineral chemical compositions 59
• 3.4. Discussion 61
• 3.5. Conclusion 67
• REFERENCES 68
• Chapter 4. Estimation of post-shock P-T conditions using silicate polymorphs in a granophyre clast within lunar meteorite 72
• ABSTRACT 72
• 4.1. Introduction 73
• 4.2. Materials and Methods 76
• 4.2.1. Samples 76
• 4.2.2. Analytical Methods 78
• 4.3. Results 79
• 4.3.1. Mineralogy and silica texture of the granophyre clast 79
• 4.3.2. Characterization of silica polymorphs in the granophyre clast: Raman spectroscopy and Color CL mapping 82
• 4.3.3. Chemical composition of silica polymorphs: Field Emission EPMA 84
• 4.3.4. Spatial distribution of silica polymorphs and feldspar in the granophyre clast 89
• 4.4. Discussion 94
• 4.4.1. Estimation of post-shock temperature and peak pressure-temperature 94
• 4.4.2. Origin of shock-induced spatial heterogeneity in the granophyre clast 99
• 4.4.3. Constraints on the thermal evolution of the granophyre clast based on silica polymorphs 100
• 4.5. Conclusion 102
• REFERENCES 104
• APPENDIX I. Publication list 110
• A1. Publication list 110
• A2. Conference List 111
• ABSTRACT (in Korean) 113