柴达木盆地断隆带对砂岩型铀成矿的约束机制OA

As a large intermountain basin located in the northeastern margin of Tibetan Plateau,Qaidam Basin hosts a series of Cenozoic fault-uplift zones.Traditional view holds that such tectonically active regions are unfavorable for uranium mineralization.However,recent uranium exploration has discovered industrial-grade uranium mineralization in several fault-uplift zones,revealing the significant prospecting potential of uranium deposit.To elucidate its metallogenic mechanisms,this study systematically investigated the geological characteristics of sandstone-type uranium mineralization within these fault-uplift zones through comprehensive field surveys,drill core observations,mineralogical analysis,and geochemical testing.The research reveals that the fault-uplift zones exert a tripartite,integral control over uranium mineralization,summarized as"sand control,fluid channeling,and orebody localization."During the syndepositional stage,the paleo-uplift background controlled the spatial distribution of favorable sandstone bodies,such as those in braided river delta systems.Subsequent sustained uplift and the associated fault activity provided dominant conduits for the upward migration of deep-seated ore-forming fluids.Finally,the structural styles shaped by these zones—particularly"anticline-fault"combinations—ultimately controlled the localization of uranium mineralization.Geochemical analysis demonstrates a significant positive correlation between uranium and deep-source elements such as Mo,Re,Cu,Pb,and Zn.Combined with the abundant presence of powdered organic matter and bitumen in the ores,which are indicative of a deep source,all these evidence collectively points to a deep-source origin of the ore-forming fluids.Based on the above findings,an exudative uranium metallogenic model was proposed to adapt the fault-uplift zones of the Qaidam Basin.All These findings not only provide direct guidance for the breakthroughs in sandstone-type uranium exploration in Qaidam Basin but also contribute valuable insights toward uranium metallogenic theories in tectonically active regions of China.