鄂尔多斯盆地巴音青格利铀矿床成矿流体驱动下的黏土矿物转变与铀的协同富集机理OA

Ordos Basin is an important multi-energy mineral-rich area in China.In its northern part,sandstone-type uranium deposits are primarily formed by interlayer oxidation,a process involving complex water-rock interactions and clay mineral alteration.This study focused on Bayinqinggeli uranium deposit to investigate forming process by comprehensively employing whole-rock geochemical analysis,X-ray diffraction(XRD),scanning electron microscopy(SEM),and electron probe techniques.The study emphasized the evolutionary sequence of clay minerals during the mineralization process and their coupling with elemental geochemical behavior.The results indicated that the transformation from montmorillonite to kaolinite was mainly driven by the acidic environment of the mineralizing fluids.The increase in organic carbon and total sulfur content was closely related to uranium reduction and precipitation processes involving microorganisms and organic matter.The coffinite as the primary uranium mineral was inferred the result from chemical alteration of asphaltic uranium and coexisted with chlorite,pyrite,calcite,among others,revealing a shift in the post-mineralization fluid environment from acidic to alkaline.This study provides new evidence for a deeper understanding of the formation mechanisms of this type of uranium deposit and offers guidance for subsequent exploration and development.