The Characteristics And Mechanism Of Interlayer Oxidation Zone Color At Shi Hongtan Uranium Deposit In Turpan-hami Basin

As the typical sandstone type uranium deposit in China,Shi Hongtan uranium deposit presents the significant geochemical zoning with various color in the interlayer oxidation zone in Turpan-Hami Basin.And the epigenetic alteration colors could be used as the macro indicators for different geochemical zonation.Such as,red zone illustrated the hematitization,while the yellow color indicated the formation of goethite and water goethite in interlayer oxidation zone.The studies indicate that the formation of different color with corresponding minerals also related to the pH value in interlayer oxidation zone.In the front line of the interlayer oxidation zone,pH value is weak acid and neutral which is favorable for the forming of goethite and water goethite.When pH value increased to neutral and weak alkaline,which is favorable for the formation of hematite.Since there is the transformation between goethite and hematite in nature.further studies show that acidic water with Fe³⁺played a positive role in the migration of uranium.When Fe³⁺is reduced to Fe²⁺,the uranium will be precipitated due to the reduction in interlayer oxidation zone.Therefore,the iron played a vital role in mineralization process in interlayer oxidation zone of sandstone type uranium deposit.