High-pressure phase equilibria of deep-mantle minerals and related materials by high-pressure experiments and calorimetry

2020 Fiscal Year Final Research Report

• Project/Area Number: 17H02986
• 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: Gakushuin University
• Principal Investigator: Akaogi Masaki 学習院大学, 理学部, 教授 (30126560)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 高圧実験 / 熱測定 / マントル / 結晶構造 / 相転移 / 相平衡 / スピネル / ペロブスカイト

Outline of Final Research Achievements

Phase changes in mantle-constituent rocks were clarified by high-pressure and high-temperature experiments. High-pressure phase transitions of aluminum- and chromium-bearing minerals were investigated, and crystal structures of newly synthesized high-pressure phases were analyzed by X-ray diffraction method. The pressure-temperature stability conditions of some of the high-pressure minerals were precisely determined by calorimetric measurements and thermodynamic calculation. Furthermore, high-pressure phase transitions of various spinel-type oxides were investigated, and systematics in the phase transitions were clarified.

Free Research Field

高圧地球科学

Academic Significance and Societal Importance of the Research Achievements

地球深部のマントルを構成する岩石・鉱物が高温高圧下で起こす相変化を従来より詳細に解明した。それらの結果は、マントルで起こるダイナミックなプロセスを理解するための基盤となる。またスピネル型酸化物が高温高圧下で起こす相転移の様式の規則性を明らかにした。それらは、新しい結晶構造や機能を持つ酸化物を高温高圧下で合成する際に有用な指針となる。