Vertical oxidation-reduction zoning in the crust of weathering as an ore control factor for uranium in hypergenic conditions

Redox zoning of the crust of weathering as a factor of uranium ore control under hypergene conditions is studied. Regular location of uranium mineralization in the profile of the crust of weathering, restricted by redox zoning, and to a certain extent related to facies type of the crust of weathering, is established. The change of redox situation in the profile of the crust of weathering determines the differences in uranium migration ability. Experimental data confirm the role of the crust of weathering as uranium source in epochs, following the weathering ones. Crusts of weathering during metallogenic studies should be considered in two aspects: oxidative zone of the crust of weathering plays the role of uranium source, involved in the processes of hypergene migration; the reductive one - is a favourable medium for localization of uranium concentrations