| Project/Area Number |
62540608
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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 |
鉱物学(含岩石・鉱床学)
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| Research Institution | Faculty of Science, Hokkaido University |
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Principal Investigator |
HARIYA Yu Faculty of Science, Hokkaido University, 理学部, 教授 (50000815)
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| Co-Investigator(Kenkyū-buntansha) |
MIURA Hiroyuki Faculty of Science, Hokkaido University, 理学部 (昭和62年次のみ), 助手 (70157436)
IRIFUNE Tetsuo Faculty of Science, Hokkaido University, 理学部, 助手 (80193704)
KIKUCHI Takeshi Faculty of Science, Hokkaido University, 理学部, 助教授 (60211190)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1987: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Mn-Mg-Fe-O system / pyroxmangite / Mn-clinopyroxene / f_<CO_2> / fH_2O / Pyroxmangite / Mn-clinoPyroxene / fH_2 / pyroxmangite |
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| Research Abstract |
Main problems on the stability relations of of manganese minerals have been approached by experimental study with CO_2 and H_2O. The experiments were conducted with oxygen and/or graphite buffers in the system C-O-H at pressuretemperature conditions corresponding to normal crustal metamorphism to understand the evolution of mineral assemblages from Ca-poor Mn-Mg-Fe carbonates admixed with silica.
Stability field of pyroxmangite solid solution contained Fe can appear at low temperature than the MnSiO_3 end member. The appearance of single phase pyroxmangite solid solution is insensitive to variations in X_<Mn> of the bulk in the range -0.8 and above. With increasing X_<Mg> and X_<Fe> in the bulk composition, carbonate solid solution+quartz react to produce pyroxmangite solid solution+Mn-clinopyroxene solid solution and Mn-clinopyroxene solid solution successively. All the reaction boundaries are insensitive to pressure, at least up to 8kb, and have gentle slope in temperature.
The reactions are also independent of the X_<CO2> of the fluid phase in the region X_<CO2> =0.21-0.53 above moderate temperatures. The slope of the InX_<CO2>-10^<-3>/TK relationship of these reactions is similar to that of the pure pyroxmangite forming reaction.
Mn-clinopyroxene solid solution can be stabilized at a low temperature than pyroxmangite solid solution from favourable bulk composition [X_<(Mg+Fe)>=0.4].
With increasing Fe content, stability field field of Mn-clinopyroxene solid solution extends toward higher X_<Mn> region as compared to that in Fe-free system.
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