A possible origin of uranium deposits in granites in special reference to the formation of SL deposit

The tectonic destruction and hydrothermal alteration of the H granite massif resulted in the formation of the green alteration zone. During this process, infiltrating hydrothermal solutions would resorb uraninite in the rocks, leading to the mobilization and thus migration of uranium into fissures and grain interstices, or being adsorbed on clay minerals. As a result, the medium and space were provided for later mineralization. In the Cretaceous period, the upper part of the green alteration zone underwent strong oxidation, followed by the resorption and then the transformation of metallicsulfides into limonite and hydrogeothite. And uranium present both in uraninite and in fissures was further mobilized and concentrated to form uranium ore deposits of economic importance in the redox boundary between the green zone and the purple zone.