Chemical Kinetics and texture interpretation of rocks at high pressures and temperatures
Project/Area Number |
60420016
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Research Category |
Grant-in-Aid for General Scientific Research (A)
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Allocation Type | Single-year Grants |
Research Field |
鉱物学(含岩石・鉱床学)
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Research Institution | Kyoto University |
Principal Investigator |
MORI Takeshi Faculty of Science, Kyoto University, 理学部, 助教授 (80125963)
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Co-Investigator(Kenkyū-buntansha) |
TATSUMI Yoshiyuki Faculty of Science, Kyoto University, 理学部, 助手 (40171722)
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Project Period (FY) |
1985 – 1987
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Project Status |
Completed (Fiscal Year 1987)
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Budget Amount *help |
¥20,500,000 (Direct Cost: ¥20,500,000)
Fiscal Year 1987: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1986: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1985: ¥14,300,000 (Direct Cost: ¥14,300,000)
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Keywords | High pressure rocks / Texture formation / Lherzolite / Clinopyroxene / Subsolidus reaction / High pressure apparatus / 化学反応論 / かんらん岩 / ガーネットのゾーニング / 反応境界の移動 / 粒間にそう元素の移動 / 幌満超塩基性岩 / 泥質物の脱水分解反応 |
Research Abstract |
We have made researches on chemical kinetics of subsolidus reactions among rock-forming minerals at high pressures and temperatures, of both synthetic and natural rocks. As natural rock samples, the Horoman peridotites and basic metamorphic xenoliths at Kibi Plateau were chosen. The most important outcome of the analysis of garnet lherzolites synthesized at high pressures using a piston-cylinder type high pressure apparatus is the experimental demonstration of differential velocities among various subsolidus chemical reactions in the garnet lherzolite mineralogy. That is, the Ca-Mg-Fe redistribuion ,that is rathe simple reaction, took place everywhere in the minerals while such an Al-related reaction as the Tschermak substitution failed at the core. This phenomena, probably due to the relative complexity of reaction mechanisms, would be directly related to the differential closure temperatures among various geothermometers. The analysis of texture and mineral chemistry of natural rocks , in conjunction with the experimental study, led us to deeper understandings in the textures and formation histories of natural rocks. For example, we could decipher that the Horoman peridotites once belonged to the garnet lherzolite facies though the peridotites now totally lack traces of garnet lherzolite facies mineralogy. Future studies : The high pressure apparatus in our laboratory can maintain pressure in lengthy period. On this benefit, we paln to make as lengthy runs as possible so that subsolidus chemical kinetics can be further understood.
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Report
(3 results)
Research Products
(6 results)