| Project/Area Number |
63114002
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| Research Category |
Grant-in-Aid for Special Project Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Wide Area
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
MARUMO Fumiyuki Tokyo Institute of Technology, Research Laboratory of Engineering Materials, 工業材料研究所, 教授 (10013492)
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| Co-Investigator(Kenkyū-buntansha) |
IIYAMA Toshimichi Chiba University, Faculty of Science, Professor, 理学部, 教授 (90107699)
KURODA Yoshimasu Shinshu University, Faculty of Science, Professor, 理学部, 教授 (20015530)
AOKI Ken-ichiro Tohoku University, Faculty of Science, Professor, 理学部, 教授 (00004276)
TAKEDA Hiroshi The University of Tokyo, Faculty of Science, Professor, 理学部, 教授 (50011523)
KUSHIRO Ikuo The University of Tokyo, Faculty of Science, Professor, 理学部, 教授 (80011526)
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| Project Period (FY) |
1985 – 1988
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| Keywords | earth's interior / high-pressure / high temperature experiment / insitu observation / high temperature transmission electron microscope / garnet / perovskite / pyroxene |
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| Research Abstract |
1. The following evidences have been revealed on formations and changes of materials accompanying large scale material transport in the earth's interior.
(1) Ultra-high pressure, high temperature experiments on MgSiO_3 showed that hte teteagonal garnet with ordered arrangements of Mg and Si over the octahedral sites ahs a wide stable retion ranging from 1600 C to the congruent melting temperature and from 17 GPA to the transition temperature to perovskite. The tetragonal garnet is more dense than the AL-free cubic garnets and in a higher entropy state than perovskite.
(2) The density of anhydrous basalt magmas increases almost linearly with increasing pressure up to 1.2 GPa. Under such condition, even calcic plagioclase floats upwards in the fractionating magma. On the other hand, the density of basalt magma becomes smaller in the presence of 3 wt% H_2O than that of intermediate plagioclase, and the crystallizaed plagioclase woulk sink even in the lower crust.
2. The following results have been obtained on crystallization and transformation of minerals with atomic scale investigations.
(1) Equimpents have been developed for in-situ observation of nucleation, growth and dissolution of silicate and oxide crystals at high temperatures up to 1600 C. Employing these equipments, retes of nucleation, crystal growth and dissolution were determined on conpouns such as Di_<85>En_<15>.
(2) A high temperature transmission electron microscope was constructed for in-situ observation of phase transformations. The processes of laihunite formation from olivine, and of the phase transitions of pyroxenes and cordierite were revealed at atomic scale.
(3) Local structures around transition-element atoms in silicate melts and glasses were investigated, showing correlations to structures of crystals appearing from the melts.
3. Non-empirical SCF-MO calculation resulted in realistic two-body central potential in SiO_2 ready to use in the molecular dynamics calculations.
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