A series of laboratory experiments to study the diffusion of radioactive tracers (''Sr, 36 C1) was performed on samples of Cambrian clays. The use of radioactive isotopes makes it possible to avoid superposition of osmotic processes, changes in migration forms of elements and other phenomena during the diffusion experiment. The self-diffusion coefficients of individual ions are evaluated, whereas binary diffusion coefficients are evaluated in the trait experiments. The dependence of diffusion coefficients on solution concentration and concentration gradient is studied.
