Progress in the research on noble gas isotope tracing of the mantle plume and its significance.

Abstract: There is appreciable difference in noble gas isotopic composition among the mantle plume, upper mantle and crust. Using this feature, the mantle plume can be well traced and recognized. The 3He/4He ratios of the mantle plume are ＞8-8.5 Ra, higher than those of the upper mantle and crust. The 20Ne/22Ne ratios of the mantle plume are ≥10.8, close to those of the upper mantle, but the 21Ne/22Ne ratios of the mantle plume are lower than those of the upper mantle. The 40Ar/36Ar ratios of the mantle plume are generally lower than those of the upper mantle. The 129Xe/130Xe and 136Xe/130Xe ratios of the mantle plume are commonly higher than those of the upper mantle and crust, over 10% higher than those of the upper mantle. The 3He/4He ratios of Cenozoic pyrolites in eastern China generally fluctuate around the end-member values of 3He/4He of the upper mantle (8±1Ra) and differ from the 3He/4He ratios of mantle plume greatly. It is widely accepted that the upwelling of the mantle plume is closely associated with the formation of large igneous provinces (LIP). The Emeishan basalt is the only LIP in China recognized universally at present by the academic community. The study of noble gas isotope tracing of the mantle plume, including the study of the Emeishan basalt, has great significance for deepening the study of the mantle plume in China and advancing the process of continental dynamic research.