| Project/Area Number |
17H01174
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Petrology/Mineralogy/Economic geology
|
|---|
| Research Institution | Okayama University |
|---|
Principal Investigator |
Xue Xianyu 岡山大学, 惑星物質研究所, 教授 (70362986)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
神崎 正美 岡山大学, 惑星物質研究所, 教授 (90234153)
|
|---|
| Project Period (FY) |
2017-04-01 – 2021-03-31
|
| Project Status |
Completed (Fiscal Year 2020)
|
| Budget Amount *help |
¥46,800,000 (Direct Cost: ¥36,000,000、Indirect Cost: ¥10,800,000)
Fiscal Year 2020: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
Fiscal Year 2019: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
Fiscal Year 2018: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
Fiscal Year 2017: ¥39,000,000 (Direct Cost: ¥30,000,000、Indirect Cost: ¥9,000,000)
|
|---|
| Keywords | 鉱物構造 / 分光法 / 水 / 高圧 / 欠陥 |
|---|
| Outline of Final Research Achievements |
Water may be present in nominally anhydrous mantle minerals in the form of OH defects, affecting the structure and dynamics of the Earth’s mantle. Thus, it is important to clarify how water is incorporated in such minerals. In this study, we have used a combined approach of NMR spectroscopy, first-principles calculation, etc. on a number of mantle minerals (enstatite, grossular, pyrope, ringwoodite, etc.), either synthesized at high pressure and high temperature or natural samples, and have revealed new insights into the incorporation mechanisms of OH defects in these minerals.
In addition, we have also carried out a comparative study on Zn silicate system in an attempt to understand how the behaviors of hydrogen in high-pressure minerals vary with cation type. We have found a new high-pressure hydrous Zn silicate phase (Zn-phase A) and have determined its crystal structure.
|
| Academic Significance and Societal Importance of the Research Achievements |
本研究により、赤外分光法などを用いた先行研究を補って、水の主要な「無水」マントル鉱物におけるOH欠陥の存在様式並びにその鉱物構造や圧力依存性を明らかにした。また、一部の鉱物については、一部の水素は強い水素結合を示し、よく用いられる赤外分光法では検出されていなかった可能性を示唆し、NMR分光法による解明の有用性を証明した。また、本研究による構造知見は、マントルの物性（電気伝導度、元素の拡散率など）並びにダイナミクスを理解するための基盤を提供した。また、亜鉛珪酸塩系に関する比較的研究は、水素の振る舞いのカチオン依存性に関する結晶化学的知見を提供した。
|
