1998 Fiscal Year Final Research Report Summary
Reaction mechanism of sheet silicates and water-Elucidation on the atomic level
| Project/Area Number |
09440184
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Petrology/Mineralogy/Science of ore deposit
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| Research Institution | The University of Tokyo |
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Principal Investigator |
MURAKAMI Takashi The University of Tokyo, Graduate School of Science, Associate Professor, 大学院・理学系研究科, 助教授 (00253295)
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| Co-Investigator(Kenkyū-buntansha) |
KOGURE Toshihiro The University of Tokyo, Graduate School of Science, Associate Professor, 大学院・理学系研究科, 助教授 (50282728)
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| Project Period (FY) |
1997 – 1998
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| Keywords | sheet silicate / electron microscopy / weathering / dissolution |
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| Research Abstract |
Mineral-water-atmosphere interactions have a great role in mass transport and global cycles at the Earth's surface. In order to understand the reaction mechanisms of sheet silicates and water on the atomic level, we analyzed solids such as rocks arid minerals weathered in nature, and those in laboratory. Reaction solutions in the laboratory were also analyzed. In natural biotite and chlorite, we found the formation of vermiculite unit layers in primary domains in one case, and direct weathering of biotite without forming secondary sheet silicates in the other case. In the early stage of dissolution of biotite both in the filed and in the laboratory, scanning electron microscopic observation revealed that Al and Fe oxides/hydroxides are formed at the edges of biotite but there are few at the cleavage surfaces. These facts and the results of thermodynamic calculations of solution data in references suggest that secondary minerals such as vermiculite and kaolinite forming between biotite layers in the early stage of dissolution occur due to the chemistry of local solutions at the edges.
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