Noble gases in silicate perovskite: Solubility, dissolution mechanism and influence on the equation of state

硅酸盐钙钛矿中的稀有气体：溶解度、溶解机制及其对状态方程的影响

• 批准号: 140003049
• 负责人: Professor Dr. Hans Keppler
• 金额: --
• 依托单位: Bayerisches Forschungsinstitut für Experimentelle Geochemie und Geophysik (BGI)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/140003049?language=en
• 关键词: Noble; gases; silicate; perovskite; Solubility

We have carried out some preliminary experiments suggesting significant noble gas solubility in (Mg,Al)(Si,Al)O3 perovskite, the main constituent of Earth´s lower mantle. Measured argon contents are in the 500 ppm range, but actual solubilities may be much higher, since the samples may not have been saturated with argon. If noble gases were highly soluble in perovskite, this would provide the long-sought reservoir for primitive volatiles in the deep Earth. It would also have implications for high-pressure research in general, since ultrahigh-pressure experiments are usually carried out in diamond cells using a noble gas pressure medium. The inferred solubilities are high enough to affect equations of state and the location of phase boundaries. In this project, (i) the solubilities of argon and xenon in silicate perovskite shall be systematically studied in multi-anvil and diamond anvil cell experiments (ii) the effect of argon in the perovskite on the equation of state shall be studied by in-situ X-ray diffraction (iii) the substitution mechanism of noble gases in silicate perovskite shall be investigated by ab-initio modeling.

我们已经进行了一些初步的实验，表明在地球下地幔的主要成分（Mg，Al）（Si，Al）O3钙钛矿中存在显着的惰性气体溶解度。测得的氩含量在500 ppm范围内，但实际溶解度可能高得多，因为样品可能没有被氩饱和。如果稀有气体在钙钛矿中高度可溶，这将为地球深处的原始挥发物提供长期寻找的储存库。这也将对一般的高压研究产生影响，因为超高压实验通常是在使用惰性气体压力介质的金刚石单元中进行的。推断的溶解度是足够高的状态方程和相边界的位置的影响。本项目将采用多砧实验和金刚石对顶砧实验系统研究氩和氙在硅酸盐钙钛矿中的溶解度;采用原位X射线衍射研究钙钛矿中氩对状态方程的影响;采用从头算模型研究稀有气体在硅酸盐钙钛矿中的替代机制。

项目成果

The origin of the terrestrial noble-gas signature

• DOI: 10.1038/nature11506
• 发表时间: 2012-10
• 期刊: Nature
• 影响因子: 64.8
• 作者: S. Shcheka;H. Keppler