Publications
Detailed Information
Study on the microstructures and seismic anisotropy of blueschist and eclogite from Ring Mountain and Jenner in California
DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | 정해명 | - |
dc.contributor.author | 하윤해 | - |
dc.date.accessioned | 2017-07-19T08:54:52Z | - |
dc.date.available | 2017-07-19T08:54:52Z | - |
dc.date.issued | 2016-02 | - |
dc.identifier.other | 000000133279 | - |
dc.identifier.uri | https://hdl.handle.net/10371/131418 | - |
dc.description | 학위논문 (석사)-- 서울대학교 대학원 : 지구환경과학부, 2016. 2. 정해명. | - |
dc.description.abstract | Seismic anisotropy has been observed in many subduction zones. During subduction of slab, the oceanic crust changes to blueschist and eclogite. Since minerals in blueschist are very anisotropic elastically, seismic properties in the subducting slab can be attributed to the lattice preferred orientation (LPO) of these minerals. We studied microstructures and seismic properties of blueschist and eclogite from Ring Mt. and Jenner in California. Blueschist samples are mainly composed of glaucophane, epidote and phengite. Eclogite samples are mostly composed of omphacite, glaucophane, epidote and garnet. We determined LPOs of minerals using SEM/EBSD and calculated seismic properties of minerals and whole rocks.
LPOs of glaucophane showed [001] axes are aligned subparallel to lineation, and both (110) poles and [100] axes subnormal to foliation. Glaucophane in samples from Jenner, however, exhibited [001] axes forming a girdle subparallel to lineation. Seismic anisotropy of glaucophane was stronger in samples from Ring Mt. than those from Jenner. Epidote showed [001] axes are aligned subnormal to foliation and (110) and (010) poles subparallel to lineation. LPOs of phengite were characterized by a maximum of [001] axes normal to foliation, with (110) and (010) poles and [100] axes aligning in a girdle parallel to foliation. Phengite showed the strongest seismic anisotropy among major minerals. LPOs of omphacite showed that [010] axes subnormal to foliation and [001] axes are aligned subparallel to lineation and foliation with a girdle in eclogites and blueschist, respectively. Seismic anisotropy of omphacite was very weak. Blueschist from Ring Mt. showed stronger seismic anisotropy than those from Jenner because samples from Jenner included high contents of garnet ± omphacite. Especially, blueschist including abundant phengite showed very strong seismic anisotropy (AVP = 30%, max.AVS = 23%). Eclogite showed much weaker seismic anisotropy (AVP = 5-6%, max.AVS = 4-6%) than blueschist (AVP = 12-30%, max.AVS = 9-23%). Therefore, strong seismic anisotropy observed in subduction zone can be more affected by blueschist than eclogite. | - |
dc.description.tableofcontents | Chapter 1. Introduction 1
Chapter 2. Geological background 3 Chapter 3. Sample description 8 Chapter 4. Analytical methods 9 4.1. Determination of chemical compositions of minerals 9 4.2. Measurement of LPOs of minerals 11 4.3. Calculation of rock seismic properties 12 Chapter 5. Results 12 5.1. Microstructure 12 5.2. Chemical compositions of minerals 14 5.3. LPOs of minerals 22 5.4. Seismic velocity and anisotropy of minerals 30 Chapter 6. Discussion 45 6.1. LPO variations of minerals 45 6.1.1. LPO of glaucophane 45 6.1.2. LPO of omphacite 47 6.1.3. LPO of epidote and phengite 48 6.2. Seismic anisotropy of epidote blueschist and eclogite in the subducting slab 49 Chapter 7. Conclusion 59 References 61 List of Tables 69 List of Figures 70 국문초록 73 | - |
dc.format | application/pdf | - |
dc.format.extent | 12505982 bytes | - |
dc.format.medium | application/pdf | - |
dc.language.iso | en | - |
dc.publisher | 서울대학교 대학원 | - |
dc.subject | blueschist | - |
dc.subject | eclogite | - |
dc.subject | phengite | - |
dc.subject | lattice preferred orientation | - |
dc.subject | seismic anisotropy | - |
dc.subject.ddc | 550 | - |
dc.title | Study on the microstructures and seismic anisotropy of blueschist and eclogite from Ring Mountain and Jenner in California | - |
dc.type | Thesis | - |
dc.description.degree | Master | - |
dc.citation.pages | 76 | - |
dc.contributor.affiliation | 자연과학대학 지구환경과학부 | - |
dc.date.awarded | 2016-02 | - |
- Appears in Collections:
- Files in This Item:
Item View & Download Count
Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.