| 下地幔温压下(Mg, Fe)SiO3钙钛矿的相稳定性 |
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| 关键词:enstatite shock recovery phase stability XRD microanalysis |
| 基金项目:国家自然科学基金面上项目(编号: 40474033)和武汉工业学院校基金(编号: 07Y15)联合资助 |
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| 摘要: |
| Stability of (Mg, Fe)SiO3-Perovskite under the Condition of Lower Mantle Pressure and Temperature |
| Shock recovery experiments with the initial sample of (Mg0.92, Fe0.08)SiO3 and MgO+SiO2 were conducted in the pressure range of 69~100 GPa (with the corresponding temperature estimated to be 2600~4300 K). XRD microanalysis of the recovered samples has yielded the following understanding: ①The main phase of the recovered sample is enstatite of the single-chain structure instead of that of` the perovskite structure. Both the XRD characteristic spectrograms of oxides SiO2 and (Mg0.92, Fe0.08)O are not observed in the recovered samples; ②the main components of recovered samples of MgO+SiO2 are SiO2 and Mg2SiO4. The experiment results show that enstatite is transformed into the perovskite structure under the shock compression whereas the perovskite structure is transformed retrogressively into the single-chain structure during the process of pressure release. It doesn’t exist the possibility of the chemical decomposition reaction from (Mg0.92, Fe0.08)SiO3 to oxides SiO2 and the production of (Mg0.92, Fe0.08)O under the temperature and pressure condition of the experiment, and hence the high-pressure phase of the enstatite-perovskite structure remains stable under the experimental condition. In addi-tion, the spectral difference between the original sample and the recovered samples might be attributed to the crystal distortion under the shock compression or the release process, and the loading process might probably re-sult in such a distortion. |
| CHEN Xiu-fang,YU Hui,GONG Zi-zheng.2009.Stability of (Mg, Fe)SiO3-Perovskite under the Condition of Lower Mantle Pressure and Temperature[J].Acta Geoscientica Sinica,30(2):210-214. |
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