The compositional ranges of Mn-pyroxenoids
| Project/Area Number |
02640645
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
人類学(含生理人類学)
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| Research Institution | National Science Museum |
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Principal Investigator |
MATSUBARA Satoshi National Science Museum, Dept. of Geology, senior resercher, 地学研究部, 主任研究員 (40000137)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Akira National Science Museum, Dept. of Geology,, 地学研究部, 室長 (70000114)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1991: ¥400,000 (Direct Cost: ¥400,000)
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| Keywords | Pyroxmangite / Rhodonite / Bustamite / Johannsenite / マ-スタ-石 / 南部石 / マンガン準輝石 |
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| Research Abstract |
Mn-pyroxenoids and clinopyroxenes from Japan were analysed using EDS. Pyroxmangite is extant under 10 % of CaSiO_3 mole, and only Ca-poor one is stable at higher temperatures. The compositional range of FeSiO_3 mole varies widely and reaches 32 mole % among studied pyroxmangites. Rhodonite may be stable under the wide temperature range, and its compositional range exsists between 10 % and 20 % of CaSiO_3 sole and under 30 % of (Fe. Mg)SiO_3 mole. Rhodonite accompanying johannsenite formed under low temperature is high-calcian, and its CaSiO_3 mole reaches about 35 %. Bustamite has wide compositional range located within the area between 30 % and 55 % of CaSiO_3 mole and under 20 % of (Fe. Mg)SiO_3 mole. In case of high temperature, bustamite is stable in the compositional area of clinopyroxene under 20 % of (Fe. Mg)SiO_3 mole. The decreasing temperature invites the appearance of johannsenite near CaMnSi_2O_6, and the distribution of clinopyroxenes on Ca(Fe, Mg)Si_2O_6- CaMnSi_2O_6 join becomes consecutive. That is, the stability field of bustamite is limited at lower temperatures. but it is able to exist outside of clinopyroxene area.
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Report
(3 results)
Research Products
(6 results)
