Combined diffusion—Infiltration of uranium in micaceous schists

Fission and particle track methods have been used to study uranium and lithium/boron distributions in muscovite and biotite schists. The results show that uranium and lithium/boron have a non-uniform distribution within grain boundaries and strained crystal lattice structures of the micas. Uranium redistribution is attributed to; (1) hydrothermal or metamorphic fluids that have redistributed the uranium together with lithium/boron by diffusion and infiltration through planar and lattice defects within the mica aggregate, (2) meteoric fluids that postdate the hydrothermal or metamorphic fluid and are also responsible for the introduction of iron and manganese concentrations within planar defect structures.