On the problems about the state of noble gases in the deep Earth

Abstract

Noble gases are chemically inert and their behavior is not always similar to those of the other elements. Their isotope ratios also reflect such effects as mass fractionation, addition of radiogenic and nucleogenic isotopes as shown in the difference between those of MORB and OIB. Further, relative abundances of primorodial components such as ³He differ between MORB and OIB, reflecting the evolution of the Earth. Noble gases have been considered to be retained mostly in the silicate phase in the interior of the Earth.In recent years, however, it has been argued that ³He might be retained in the core. But there are no trial to explain the state of heavier noble gases including Xe from such a point of view. In my talk, I will discuss the problems of the sate of noble gases in the Earth's deep interior and its relationship with the evolution of the Earth, referring the recent publications.