Relationship between a forming process of uranium ore deposit, and sedimentary and diagenetic processes

Sasao, Eiji   

Uranium deposits occur in various kinds of rocks at the earth's surface. Sedimentary rock has long been known to be particularly important as the host rock of economic uranium deposits. Source of uranium is generally considered to be basement granitic rock. Recent studies suggest that source of uranium may be released by decomposition of uranium-bearing heavy minerals and volcanic glass during diagenesis. This presentation is held in an invited speaker session regarding sedimentary rock. The author firstly introduces outline of uranium deposits occur in sedimentary rock and then discusses the relationship between uranium ore deposit, and sediment and diagenetic processes in some uranium deposits including the Tono uranium deposit as case examples.