青海省查查香卡铀矿床矿石特征及铀的存在形式研究

Ore Characteristics and Existing Form of Uranium in Chachaxiangka Uranium Deposit, Qinghai Province

铀矿石特征和铀存在形式有助于查查香卡铀矿床成因和成矿过程的研究。查查香卡铀矿石地质特征分析和显微研究表明铀矿石主要为糜棱岩化斜长角闪岩、碎裂岩、角砾岩及正长花岗岩,矿石经历了韧性和脆性变形,铀矿物与长英质脉体关系密切,呈脉状分布。矿石放射性径迹、化学分析显示,矿石中铀矿物主要以铌钛铀矿为主,其次为晶质铀矿、铀钍矿及钍铀矿物,矿石U含量与Th、Nb、Ce、La和稀土总量呈正相关性,其中Nb、Ce、La、Th含量可达工业品位。综合分析,查查香卡铀矿床至少发育两期铀矿化,前期为独立铀矿化期或者铀钍矿化期,后期为铀、钍稀土综合矿化期。

The characteristics of uranium ore and the existing form of uranium are helpful in the investigation of the genesis and metallogenic process of Chachaxiangka uranium deposit.The geological characteristics and microscopic study of Chachaxiangka uranium ore show that uranium ore is mainly mylonite plagioclase amphibolite schist,cataclasite,breccia and orthoclase granite.The ores have undergone ductile and brittle deformation,uranium minerals in the ore are in the form of vein,which is closely related to the felsic vein.The ore radioactivity track and chemical analysis indicate that the uranium minerals in the ore are mainly mendeleevite,followed by uraninite,uranothorite and thoruraninite.The U content of the ore is positively correlated with the contents of Th,Nb,Ce,La and the total amount of rare earth elements,in which the content of Nb,Ce,La,Th elements can reach the industrial grade.Comprehensive analysis suggests that at least two stages of uranium mineralization are developed in Chachaxiangka uranium deposit,which are independent uranium mineralization or U-Th mineralization in the early stage,and U,Th and rare earth elements comprehensive mineralization in the later stage.