Atomic diffusion in defect fields in mantle minerals

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03750
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: TOMIOKA Naotaka 国立研究開発法人海洋研究開発機構, 高知コア研究所, 主任技術研究員 (30335418)
• Co-Investigator(Kenkyū-buntansha): 伊藤 元雄 国立研究開発法人海洋研究開発機構, 高知コア研究所, グループリーダー代理 (40606109) ; Das Kaushik 広島大学, 理学研究科, 准教授 (40634077) ; 安東 淳一 広島大学, 理学研究科, 教授 (50291480)
• Research Collaborator: OHNISHI Ichiro
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 欠陥 / マントル鉱物 / 原子拡散 / 透過電子顕微鏡

Outline of Final Research Achievements

We have performed nanoscale observations of natural and synthetic silicate minerals by transmission electron microcopy to clarify cation diffusion processes in their defect fields. Based on relationships between defect structures and elemental distributions in the samples, it was qualitatively revealed that dislocations and stacking faults behave as a high-speed diffusion path within mineral grains. In addition, during characterization of the defect structures, we incidentally discovered new high-pressure phases of olivine and pyroxene, which provide some insights for better understanding of transformation mechanisms of silicate minerals in subducting lithospheres into the Earth’s mantle, in shocked meteorites.

Free Research Field

鉱物学