居隆庵铀矿床酸碱交代叠合成矿特征

坑道地质观测和取样研究表明,居隆庵铀矿床不仅发育酸交代型铀矿化,也普遍存在碱交代型铀矿化,而且碱交代早于酸交代,酸、碱交代型铀矿化在空间上叠合形成富矿。碱交代型矿化蚀变矿物组合为钠长石-赤铁矿-绿泥石-碳酸盐;酸交代型矿化蚀变矿物组合为萤石-伊利石-绿泥石-磷灰石。碱交代型矿石铀主要以分散吸附状态存在;酸交代型矿石铀主要存在于沥青铀矿中,少量存在于钛铀矿、铀(钍)石中。碱交代型矿石具有富Na、低K含量和LREEHREE等特点,矿化指示元素组合为U、Sr、W、Y、LREE、Yb、Th;酸交代型矿石有富F、S、P,HREELREE等特点,矿化指示元素组合为U、P、Sb、W、Yb、Lu、Th、Y、HREE、Mo、Cd、Pb。

Metallogenic Characteristics of Alkali and Acid Metasomatism in Julong'an Uranium Deposite

Geological observation in mine tunnel and sample study showed that there was not only acid metasomatic uranium mineralization,but also widespread alkali metasomatism in Julong'an deposit.Alkali metasomatism was earlier than acid metasomatism,rich ore is the superposition products of the two kinds alteration.Mineral assemblages for alkali metasomatic mineralize alteration is albite-hematite-chlorite-carbonate,and mineral assemblages for acid metasomatic mineralize alteration is fluorite-illite-chlorite-apatite.Uranium in alkali metasomatic ore mainly exists as adsorbed state,but in acid metasomatic ore mainly exists in pitchblende,some exists in brannerite and thorite.Alkali metasomatic ore is rich in Na and poor in K and it is characterized by LREE＞ HREE.The element association that indicates mineralization is U,Sr,W,Y,LREE,Yb,Th.Aicd metasomatic ore is rich in F,S,P and it is characterized by HREE＞LREE.The element association that indicates mineralization is U,P,Sb,W,Yb,Lu,Th,Y,HREE,Mo,Cd,Pb.