超深金刚石包裹体:对深部地幔物理化学环境的指示

The Inclusions in Superdeep Diamonds:Indication and Response to Deep Mantle Physical and Chemical Environment

超深金刚石及其包裹体是探究深部地幔组成及物理化学环境的重要样本。梳理了超深金刚石中新发现的典型矿物包裹体及其组合,并结合前人高精度原位分析、高温高压合成金刚石实验的研究成果,综述分析了超深金刚石矿物包裹体及其组合指示的深度范围、微量元素与温压条件之间的关系,超深地幔水的赋存矿物相、金属相以及强还原环境新认识,残留的俯冲洋壳可能是深部地幔水的重要储库,超深金刚石及其包裹体对深俯冲及深部碳循环的指示等研究进展。指出我国学者虽然在华北、扬子克拉通金刚石中也发现了指示超深来源的矿物包裹体,在超高压金刚石形成及蛇绿岩型金刚石成因研究方面获得了某些重要进展,但对超深金刚石包裹体的研究仍然有待深入。

Superdeep diamonds and their inclusions are important samples to probe the physical and chemical environment and constitution of Earth’s deep mantle. By combining the studies of high-precision in-situ analysis and HPHT synthetic diamond experiments,and by reviewing the new discovery of classical mineral inclusions and their combinations,the ranges of different inclusion combinations,as well as the relationship between trace elements and temperature-pressure conditions were reoriented. The so-called nominally anhydrous minerals combinations, metal phases and redox environments in superdeep mantle were also affirmed.Meanwhile,the recent findings of inclusions and isotopes in superdeep diamonds support the fact that the remaining subduction ocean crust may be a significant reservoir of the deep mantle’s water and the deep mantle carbon cycle is closely related to oceanic subduction. Furthermore,although Chinese scholars have discovered some kinds of superdeep inclusions in diamonds from North China Craton and Yangtze Craton,and made considerable progress in the study of the formation of UHP diamonds and the genesis of ophiolite diamonds,there are still many scientific questions about superdeep diamonds that require further research.