Deep mantle hydrogen in the pyrite-type FeO2–FeO2H system

• 来源期刊: 地学前缘（英文版）
• 年，卷（期）: 2021,（2）
• 所属期刊栏目: Editorial
• 页码范围: 975-981
• 页数: 7页
• 语种: 英文

摘要

The pyrite-type FeO2 and FeO2H were synthesized at the pressure-temperature conditions relevant to Earth's deep lower mantle. Through the water-iron reaction, the pyrite-phase is a good candidate to explain the chemical heterogeneities and seismological anomalies at the bottom of the mantle. The solid solution of pyrite-type FeO2 and FeO2H, namely the FeO2Hx (0≤x≤1), is particularly interesting and introduces puzzling chemical states for both the O and H atoms in the deep mantle. While the role of H in the FeO2–FeO2H system has been primarily investigated, discrepancies remain. In this work, we summarize recent progress on the pyrite-phase, including FeO2, FeO2H, and FeO2Hx, which is critical for understanding the water cycling, redox equilibria, and compo-sitional heterogenicities in the deep lower mantle.