Mineralogy and Geochemistry of granitic pegmatite, Lichenhills, Outback Nunatak, North Victoria land, Antarctica

• Main Author: 김태우
• Other Authors: 이인성, 자연과학대학 지구환경과학부
• Format: Thesis
• Language: English
• Published: 서울대학교 대학원 2017
• Subjects: pegmatite; tourmaline; petrogenetic indicator; S-type; chemical zoning; schorl-elbate; ferrischorl substitution; 550; Lichen Hills; Outback Nunataks; Victoria Land; Antarc*; Antarctica
• Online Access: https://hdl.handle.net/10371/131447

학위논문 (석사)-- 서울대학교 대학원 : 지구환경과학부, 2017. 2. 이인성. Pegmatite is Macrocrystalline rock and composition of rock forming minerals is similar to granite. Tourmaline is boron-rich mineral which is much content in pegmatite. General chemical formula is XY3Z6Si6B3O27(OH,O,F)4. Tourmaline have useful information about the environment and conditions of deposition. And significance of petrogenetic indicator recently has gained more attention. Besides, variability in its crystal-chemistry reflects physical and chemical changes during crystallization.(Henry and Guidotti et al., 1985 Jolliff et al., 1986). The study area is located in Lichen hills and Outback Nunatak, North Victoria land, Antarctica. Lichenhills rocks are composed of granitoids, leucogranites and dolerites. Outback nunatak rocks are composed of granitic pegmatite and Precambrian schist. So, Igneous rocks of Outback Nunatak and igneous rock of Lichenhills are from same Granite habour Intrusive, but origin is little bit different. Lichen hills' rocks are more close to S-type rather than Outback nunataks. In Outback nunataks pegamatie, tourmaline is well discovered. Due to chemical difference, zoning is well developed on 001 side of macrocrystalline tourmaline. These tourmalines belong to schorl-elbaite solid solution and which indicate that Li, Mg contents is poor, Al, Fe contents is abundant when tourmaline were formed. Ferrischorl (ferric oxide)substitution (Fe3+Al-1) from core to rim occur. This means oxidation state of hydrothermal fluid increase at late period making rim of tourmaline. This can be done by mixture of hydrothermal fluid or supergene water which is more oxidizing fluid or boiling of hydrothermal fluid. 1. Introduction 1 2. Geological Setting & Sample information 3 3. Method 6 4. Result and Discussion 9 4.1 Macroscopy & Microscope observation 9 4.2 Chemical composition 12 4.3 Tourmaline observation 17 4.4 Tourmaline geochemistry 19 5. Conclusion 24 6. Reference 27 Figures, Tables 31 Abstract in Korean 86 Master