Phase equilibria and thermodynamic, properties of granulite facies minerals.

麻粒岩相矿物的相平衡和热力学性质。

• 批准号: 11640481
• 负责人: KAWASAKI Toshisuke
• 金额: $ 2.3万
• 依托单位: Ehime University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640481/
• 关键词: ultra high-temperature granulite; orthopyroxene-garnet geothermometry; Ol+Cpx; Ca-Mg olivine; Opx+Spr+Sil; Opx+Spr+Qtz; lower crust; thermodynamic properties; 斜方輝石-サグロ石地質温度計; ザクロ石; Fe-Mg分配; 斜方輝石+スピネル+石英; 珪線石; ザクロ石の相関係; グラニュライト; 中間領域

1. The theoretical and experimental investigations were carried out on the Ca-Fe-Mg partitioning between olivine and clinopyroxene and on the miscibility of Ca-Mg olivine. Both olivine and clinopyroxene can be approximated as the two-site asymmetric regular solution cooperating intracrystalline exchange equilibria. The Fe-Mg distribution coefficient increases with the Ca content, Fe/(Fe+Mg) of the system and h pressure, but the increase with pressure is very small. The solvus of the Ca-Mg olivine becomes narrow with pressure due to the negative excess volume of this solid solution.2. The high pressure experiments were carried out to constrain the phase relations in the Mg_3Al_2Si_3O_<12>(pyrope composition) and (Mg_<0.75>, Fe_<0.25>)_3Al_2Si_3O_<12>(Prp_<75> composition) systems. The system equivalent to the Mg-rich garnet composition never directly break down to the low-pressure phase assemblages without any garnet phases, and has an intermediate P-T field including garnet + orthopyroxene + sillimanite + quartz, as well as garnet + orthopyroxene + sapphirine + quartz as decreasing pressure.3. High pressure experiments reveals that an orthopyroxene granulite from McIntyre Island, Enderby Land, East Antarctica experienced retrograde metamorphism at 11.2 kbar and 895℃ and subsequently passed at a certain pressure between 10.9 kbar and 11.4 kbar at 873℃.

1.对橄榄石与单斜辉石之间的Ca-Fe-Mg分配以及Ca-Mg橄榄石的混溶性进行了理论和实验研究。橄榄石和单斜辉石都可以近似为配合晶内交换平衡的双位不对称正规溶液。Fe-Mg分配系数随Ca含量、体系Fe/（Fe+Mg）和压力的增大而增大，但随压力的增大而增大的幅度很小。由于钙镁橄榄石固溶体的负过剩体积，固溶线随压力的增大而变窄.本文通过高压实验研究了Mg_3Al_2Si_3O_（镁铝榴<12>石成分）和（Mg_<0.75>，Fe_<0.25>）_3Al_2Si_3O_<12>（Prp_<75>成分）体系的相关系。与富镁石榴子石成分相当的体系不会直接分解成不含石榴子石相的低压相组合，而是具有一个中间的P-T场，包括石榴子石+斜方辉石+硅线石+石英，以及随压力降低的石榴子石+斜方辉石+硅线石+石英.高压实验表明，东南极恩德比地麦金泰尔岛的斜方辉石麻粒岩在11.2 kbar和895℃下经历了退变质作用，随后在873℃下以10.9 kbar至11.4 kbar之间的一定压力通过。

项目成果

T.Kawasaki: "Thermodynamic analysis of partitioning of Ca, Fe and Mg between olivine and clinopyroxene." Geochemical Journal. 33. 33-58 (1999)

T.Kawasaki：“橄榄石和单斜辉石之间 Ca、Fe 和 Mg 分配的热力学分析。”

T.Kawasaki and Y.Motoyoshi: "High-pressure and high-temperature phase relations of an orthopyroxene granulite from McIntyre Island, Enderby Land, East Antarctica."Polar Geoscience. 13. 114-133 (2000)

T.Kawasaki 和 Y.Motoyoshi：“来自东南极洲恩德比地麦金太尔岛的斜方辉石麻粒岩的高压和高温相关系。”极地地球科学。

T.Kawasaki: "Thermodynamic analysis of partitioning of Ca, Fe and Mg between olivine and clinopyroxene."Geochemical Journal. 23. 33-58 (1999)

T.Kawasaki：“橄榄石和单斜辉石之间 Ca、Fe 和 Mg 分配的热力学分析。”地球化学杂志。

T.Kawasaki: "Thermodunamic analysis of partitionig of Ca.Fe and Mg between olivine and clirdopyroxene"Geochem.J.. 33. 33-58 (1999)

T.Kawasaki：“橄榄石和绿辉石之间 Ca.Fe 和 Mg 分配的热力学分析”Geochem.J.. 33. 33-58 (1999)