世界核地质科学2025，Vol.42Issue(2)：277-290,14.
鹿井铀矿田QFⅤ号矿带东段赋矿花岗岩的岩石学、地球化学特征
Petrography and geochemical characteristics of uranium-bearing granite in the east section of QFⅤ belt,Lujing uranium ore-field
摘要
Abstract
In the Xiaguxuan area of the eastern QFⅤ ore belt in the Lujing uranium ore-field,siliceous vein type uranium mineralization occurs.The ore-bearing rock is medium-coarse-grained porphyritic biotite granite.The hydrothermal alteration near the ore mainly includes hematitization,silicification,chloritization and carbonatization.Zircon U-Pb chronology,petrography and petrogeochemical analysis show that the zircon U-Pb concordant age of the uranium-bearing fresh granite is 228.3 Ma and the weighted average age is 228.9 Ma,which was formed in the second stage of the Indosinian period(Late Triassic).The major elements are characterized by high potassium calc-alkaline series and weakly peraluminous granite,with high contents of silicon and titanium,low contents of magnesium and iron,slightly low aluminum,rich in alkalis and potassium and low in sodium.Among the trace elements,Ba,Sr and Ti are depleted,while Rb,Th,Pb and Nd are enriched.The rare earth distribution curve is of light rare earth enrichment type with right inclination,and there is obvious fractionation between light and heavy rare earth elements,with obvious negative Eu anomaly,which is consistent with the geochemical characteristics of S-type granite.It is considered through analysis that the ore-hosting granite in the Xiaguxuan area may be the product formed by the partial melting of the aluminous shallow metamorphic rock series in the upper crust due to decompression and temperature increase under the background of the transition from compression to extension in the Late Triassic.Compared with normal granite,the ore-bearing granite has a higher SiO2 content,a multiple increase in the contents of CaO and P2O5,as well as the ratios of Fe2O3/FeO and HREE/LREE,and high contents of U and P,etc.All these indicate that the aggregation and precipitation of U in the study area are closely related to the chemical activities of P,LREE and HREE.These summarized chemical indexes are useful indicators for searching for siliceous vein type uranium mineralization in the inner zone of the granite body.关键词
花岗岩型铀矿/岩石地球化学/锆石U-Pb年龄/鹿井矿田Key words
granite-type uranium mineralization/lithogeochemistry/zircon U-Pb age/Lujing ore-field分类
地质学引用本文复制引用
吕川,陈昌,聂斌..鹿井铀矿田QFⅤ号矿带东段赋矿花岗岩的岩石学、地球化学特征[J].世界核地质科学,2025,42(2):277-290,14.基金项目
国家自然科学基金(编号:42062006,42273028)、核资源与环境国家重点实验室开放基金(编号:2020NRE08)和中国核工业地质局地勘项目(编号:202231)联合资助 Supported by National Natural Science Foundation(No.42062006,42273028),Open Fund for State Key Laboratory of Nuclear Resources and Environment(No.2020NRE08)and Geological Exploration Project of China Nuclear Geology(No.202231) （编号:42062006,42273028）
