滇西梁河盆地砂岩型铀矿化特征及控矿因素  

The characteristics and ore controlling factors of sandstone-type uranium mineralization in Lianghe basin,western Yunnan

作　　者：张亮 孙泽轩 莫帮洪 张凯 邓祖林 ZHANG Liang;SUN Zexuan;MO Banghong;ZHANG Kai;DENG Zulin(Research Institute No.280,CNNC,Guanghan,Sichuan 618300,China)

机构地区：[1]核工业二八〇研究所,四川广汉618300

出　　处：《世界核地质科学》2021年第2期207-217,共11页World Nuclear Geoscience

基　　金：中国核工业地质局“滇西梁河盆地平山—清水地区铀矿资源调查评价”项目(编号:2020-32)资助。

摘　　要：梁河盆地是滇西地区砂岩型铀矿赋矿盆地之一,现已探明砂岩型铀矿床2个。在野外调查的基础上,结合钻探查证,对梁河盆地砂岩型铀矿化特征及控矿因素进行研究,结果表明,梁河盆地内已探明砂岩型铀矿床定位于冲积扇扇中颗粒流-砾质辫状河沉积砂体中。铀矿化与潜水层间氧化带关系密切,铀矿体定位于潜水层间氧化带前锋与上、下翼。热水改造作用有利于基底岩石中铀的淋出,并沿断裂带上升进入沉积盖层中,在富含有机质、炭质的地段被吸附沉淀,叠加在潜水层间氧化带形成的铀矿体上,形成富铀矿体。铀矿化受蚀源区岩石、基底凹槽(冲积扇扇体)、地层层位、岩性岩相、潜水层间氧化带控制,热水改造作用控制了富铀矿体的展布。研究成果对在梁河盆地内开展砂岩型铀矿找矿工作具有一定的指导意义。Lianghe basin is a sandstone-type uranium deposits production area in western Yunnan.Two sandstone-type uranium deposits have been discovered.On the basis of field investigation and drilling verification,the characteristics and ore controlling factors of sandstone-type uranium mineralization were studied.The results showed that the deposits are located in sand body of the middle part of alluvial fan of grain flow sedimentary and gravel braided river sedimentary.The uranium mineralization is closely related to the phreatic interlayer oxidation zone.Uranium ore bodies are located in the front,upper and lower wings of the phreatic interlayer oxidation zone.The hydrothermal reformation is favorable for leaching uranium from the basement rocks and ascending along the fault into the sedimentary cover,which is adsorbed and deposited in rich organic,carbonaceous region,and the richer uranium ore bodies are formed by superimposed uranium ore bodies formed by phreatic interlayer oxidation zone.Uranium mineralization is controlled by source rocks,basement troughs(alluvial fans),strata,lithology and lithofacies,phreatic interlayer oxidation zone,and the distribution of richer uranium orebody is controlled by hydrothermal reformation.

关 键 词：潜水层间氧化带 砂岩型铀矿 控矿因素 热水改造作用 梁河盆地 滇西 

分 类 号：P619.14[天文地球—矿床学]