1992 Fiscal Year Final Research Report Summary
Grain growth of quartz in geological processes
| Project/Area Number |
01420015
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
鉱物学(含岩石・鉱床学)
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| Research Institution | Osaka City University |
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Principal Investigator |
AIKAWA Nobuyuki Osaka City Univ., Fac. of Sci., Professor, 理学部, 教授 (20047327)
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| Co-Investigator(Kenkyū-buntansha) |
SHINODA Keiji Osaka City Univ., Fac. of Sci., Research Assist., 理学部, 助手 (40221296)
FURUYAMA Katsuhiko Osaka City Univ., Fac. of Sci., Assoc. Professor, 理学部, 助教授 (10112525)
YOSHIDA Masaru Osaka City Univ., Fac. of Sci., Professor, 理学部, 教授 (30047112)
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| Project Period (FY) |
1989 – 1992
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| Keywords | Quartz / Infrared Spectroscopy / Water Species / Recrystallization / Grain Growth / Thermal History |
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| Research Abstract |
The water in rocks and minerals plays an important role in the formation process of microtexture of minerals. Chemical species, content and distribution of water in quartz, which is the major constituent mineral in rocks of upper crust, was studied for the appreciation of the role of water in geological processes. 1. We studied the content and chemical species of water in quartz which is nominally unhydrous mineral. (1) The method of the measurement of characteristic IR spectra of water species in optical anisotropic crystals was contrived. (2) The determination method of the content of water in quartz was realized by the mesurement of specimen's thick newly devised. (3) The possibility of realizing the orientation determination of OH dipole in the crystal structure was increased. 2. The research in thermal recrystallization of quartz in nature clarified the followings: (1) The internal strain of deformed quartz decreases on recrystallization processes. (2) The total water content in quartz decreases with the degree of recrystallization. (3) The nuclei of recrystallizationare due to the formation of strain free regions in deformed quartz resulting from water asited dislocation motion. (4) the nuclei start to grow with assimilating the strained region. (5) The intragranular water will contribute to the promotion of the growth of recrystallized quartz. 3. The water content of deformed quartz grains in granitic rocks along the Median Tectonic Line was investigated. The total water content tends to increase with the degree of deformation. This result is very attactive in relation to the deformation mechanism of quartz in nature. 4. The contens and chemical species of Water in minerals (ex. olivine, staulorite, topaz etc.) are still being studied in relation to the formation of their microstructure and texture.
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