地球の資源と環境

ウランの地球化学サイクルを例として

抄録

A mineralogical view of the earth's resources and environment is given by taking an example of the global geochemical cycle of uranium. The formation of U deposits is closely related to the evolution of the atmosphere, oceans, crust, microorganisms and plants. U is hence taken as a significant benchmark of the geohistory. The short-term geochemical cycle of U is considered to be mainly controled by the weathering of U deposits and the sink of U in marine sediments. This kind of short-term cycles of U and heavy metals are very important for the environmental problems such as the radioactive waste disposal. New methodologies such as microspectroscopic methods and the realistic geochemical kinetics should be developed in order to clarify mineralogical forms of unknown phases containing U and heavy metals and quantify the kinetics of their formation.