稀有气体在深部地质研究中的意义

Significance of noble gas study in deep process research

幔源物质中的稀有气体蕴藏着丰富的地球深部过程信息。它们可对地幔结构、地幔脱气历史、大陆地幔不均一性、幔源岩浆演化和CO2天然气成因等研究提供独特的示踪作用。结合中国东部地幔捕虏体的资料,综述了稀有气体在这些方面的研究进展。研究表明,MORB源和OIB源玄武岩稀有气体组成差异强烈支持地幔双层结构的存在,地幔脱气过程主要受溶解度控制脱气模式(SCD)控制;同时,中国东部地幔存在不均一性可以在稀有气体方面得到印证;郯庐断裂可能为东部幔源无机CO2的脱出提供了良好的通道。

Noble gases in mantle materials contain abundant information on the deep processes. They can be used to track the mantle structure, degassing history, inhomogeneity, magma evolution and the genesis of natural CO2. With the noble gas isotopic data of mantle xenoliths from eastern China, the main advance are summarized in this paper. The study indicates strong composition differences between noble gases from MORB and OIB supporting two-layer mantle structure. Mantle degassing process is controlled mainly by SCD model. That mantle beneath eastern China is inhomogeneous is confirmed by noble gases. The Tanlu Fault may provide a good channel for the degassing of mantle inorganic CO2 in eastern China.