【摘要】 文章通过对鄂尔多斯盆地东北部地区断裂体系和构造发展演化分析,指出铀成矿受断裂控制明显,主矿体就位于盆地内主要隐伏断裂附近,断裂活动对成矿起建设性作用的同时也起一定的破坏作用。构造发展演化阶段决定了成矿过程,目标层抬升剥蚀出露地表的时期和持继时间的长短对成矿类型和成矿阶段有着重要的控制作用。据此将成矿划分为潜水氧化阶段、早期古层间氧化阶段、晚期古层间氧化阶段和新层间氧化阶段。两期古层间氧化阶段地下水流动方向以SE向为主,铀源区主要是富铀的阴山山系,形成了分别为120 Ma和80 Ma的铀矿体。新层间氧化阶段地下水流动方向为NW向,铀源区为相对贫铀的吕梁山山脉,单独由其控制的地段铀矿化较差,但新层间氧化带与古层间氧化带相互叠加改造地段,矿化程度明显提高,形成20 Ma和8 Ma的铀矿体。更多还原

【Abstract】 In this article,analysis on the fault system and tectonic evolvement in research area indicates that faults clearly control uranium distribution because main the ore body locates near the fault.Fault action is not only active,but also destructive to uranium metallization to some extent.The phases of the structual evolvement decide metallogenic process,period and persistence of stripped target stratum,and control metallogenic type and phases.Hereby,the four metallogenic phases,include phreatic oxidation,early interlayer oxidation,later interlayer oxidation and new interlayer oxidation,are divided.Different tectonic stress determines the directions of groundwater recharge and uranium source region.The groundwater flowed from southeast in early and later interlayer oxidation phases,whose uranium source region was Yinshan mountain system which was rich in uranium,and formed 120 Ma and 80 Ma uranium ore-body.The groundwater flowed from northwest in the new interlayer oxidation phase,and the uranium source region was Lüliang mountain which was poor in uranium.If mineralization is only controlled by the new interlayer oxidation belt,it will be poor.The uranium ore-body will richen when the ore-bodies stack and rebuild together in the old and new interlayer oxidation belts.The uranium ages in the new interlayer oxidation belt are 20 Ma and 8 Ma.更多还原