摘要
芨岭矿床位于甘肃龙首山铀成矿带中段,是我国北方钠交代型铀矿床的典型代表之一。本次通过岩矿鉴定、电子探针分析,结合电子探针U-Th-Pb化学法和LA-ICP-MS U-Pb同位素方法,对芨岭铀矿床铀矿物特征及成矿年代学进行了研究。芨岭矿床铀的赋存形式以独立铀矿物为主,少量以吸附铀及含铀副矿物形式存在。铀矿物有沥青铀矿、铀石、氧化型沥青铀矿、晶质铀矿及次生铀矿物,其中沥青铀矿为主要铀矿物。电子探针矿物成份分析显示,在不同类型铀矿物中沥青铀矿铀含量最高,晶质铀矿化学成份总量及钍、铅含量较高;氧化型沥青铀矿为铀矿物的派生产物,其化学成份变化较大且总量偏低;晶质铀矿稀土元素总量较高,轻稀土元素相对亏损,重稀土元素相对富集,铕异常明显;沥青铀矿稀土元素总量较低,轻稀土元素相对富集,重稀土元素相对亏损,轻重稀土元素分馏明显;晶质铀矿形成时代为441 Ma,可能代表了赋矿围岩(中粗粒似斑状花岗岩)的形成时代,沥青铀矿年龄为99 Ma和50 Ma,可能代表了芨岭矿床的两期热液铀成矿作用时代。
The Jiling deposit is located in the middle part of the Longshoushan uranium metallogenic belt in Gansu Province,which is one of the typical representative of sodium metasomatic uranium deposits in the North China.The uranium mineralogical characteristics and metallogenic chronology of the Jilng uranium deposit are studied by petrographic observation,electron probe analysis,EPMA U-Th-Pb chemistry and LA-ICP-MS U-Pb isotope analyses.The occurrence of uranium in the ore is mainly as independent uranium minerals,with a small amount as adsorbed uranium and uranium bearing accessory minerals.Uranium minerals include pitchblende,uranite,oxidized pitchblende,uraninite and secondary uranium minerals.Among them,pitchblende is the main uranium mineral.Pitchblende has the highest uranium content in different types of uranium minerals;the total chemical composition and thorium and lead content of uraninite are relatively high;oxidized pitchblende is a derivative product of uranium minerals,with large chemical composition changes and low total amount;uraninite mainly consists of UO 2 and SiO 2.Thorite is uranium bearing mineral,with main components of ThO 2 and SiO 2.The total amount of rare earth elements in uraninite is relatively high,the light rare earth elements are relatively deficient,the heavy rare earth elements are relatively enriched,and the europium anomaly is obvious.The total amount of rare earth elements in pitchblende is relatively low,and the light rare earth elements are relatively enriched.The age of uraninite is 441 Ma,which may represent the formation age of host rock(medium coarse porphyritic granite).The age of pitchblende is 99 Ma and 55 Ma,which may represent the two-stage of hydrothermal uranium mineralization in the Jiling deposit.
作者
王生云
范洪海
顾大钊
钟军
陈金勇
宋继叶
朱泉龙
王刚
王伟
邵东
荣骁
宋振涛
WANG Sheng-yun;FAN Hong-hai;GU Da-zhao;ZHONG Jun;CHEN Jin-yong;SONG Ji-ye;ZHU Quan-long;WANG Gang;WANG Wei;SHAO Dong;RONG Xiao;SONG Zhen-tao(Beijing Research Institute of Uranium Geology,Beijing 100029,China;China National Nuclear Corporation,Beijing 100045,China;NO.203 Research Institute of Nuclear Industry,Xianyang 712000,China;Airborne Survey and Remote Sensing Center of Nuclear Industry,Shijiazhuang 050002,China)
出处
《东华理工大学学报（自然科学版）》
CAS
2020年第6期501-513,共13页
Journal of East China University of Technology(Natural Science)
基金
中国核工业地质局铀矿地质科研项目(201654,201928-3)
国家自然科学基金项目(41772082,41602080)
中核集团公司预研项目(3210408)。
关键词
芨岭钠交代型铀矿床
铀矿物特征
成矿年代学
龙首山成矿带
Jiling Na-metasomatism uranium deposit
characteristics of uranium minerals
metallogenic chronology
Longshoushan metallogenic belt
