松辽盆地南部开鲁坳陷姚家组砂岩物源示踪研究——来自岩石地球化学及锆石U-Pb年代学的制约  

Provenance Tracing of Yaojia Formation Sandstone in Kailu Depression,Southern Songliao Basin:Constraints From Petrogeochemistry and Zircon U-Pb Chronology

作　　者：冯绍南 严兆彬[1] 张文文 吴修俣 FENG Shaonan;YAN Zhaobin;ZHANG Wenwen;WU Xiuyu(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang,Jiangxi 330013,China)

机构地区：[1]东华理工大学核资源与环境国家重点实验室,江西南昌330013

出　　处：《铀矿地质》2024年第4期633-647,共15页Uranium Geology

基　　金：国家自然科学基金项目(编号:42072009、42062008)资助。

摘　　要：针对可地浸砂岩型铀矿潜在铀储层预测和铀资源评价而言,明确赋矿砂体的物源是关键。文章以松辽盆地南部开鲁坳陷上白垩统姚家组砂岩为研究对象,通过岩石地球化学及锆石年代学分析工作,探讨姚家组沉积物来源,结果表明:姚家组砂岩稀土元素含量为100.08×10^(-6)~134.06×10^(-6),以轻稀土富集、重稀亏损、铕负异常为特征;所有样品稀土元素配分模式曲线高度一致,表明姚家组砂岩来自于同一物源体系;利用∑REE-La/Yb、HfLa/Th、Zr/Sc-Th/Sc和Cr/Th-Th/Sc图解结合砂岩镜下特征综合判断,姚家组砂岩的源岩为长英质岩石;碎屑锆石UPb测年显示姚家组砂岩年龄主要集中分布在3个年龄区间,分别为110~180 Ma,230~280 Ma,1695~2171 Ma。结合地层划分、岩石微量和稀土元素特征、盆缘岩浆岩年代以及区域构造演化,指出姚家组沉积物来源于大兴安岭南段乌兰浩特地区。For the potential prediction and the evaluation of in-situ leachable sandstone type uranium deposit,the source of ore-bearing sand body it is the key factor.In this paper,the microtrace,rare earth elements and zircon chronology of sandstone samples from the Upper Cretaceous Yaojia Formation in the southern margin of Songliao Basin was studied for the tracing the source.The results showed that the content of REE is 100.08×10^(-6)~134.06×10^(-6),which is characterized by the enrichment of LREE,flat of HREE and moderate negative Eu anomaly.The REE pattern of all samples are highly consistent,indicating that the source of Yaojia Formation came from the same source system.According toΣREE-La/Yb,Hf-La/Th,Zr/Sc-Th/Sc and Cr/Th-Th/Sc diagrams combined with the microscopic characteristics of sandstone,the source rocks was found to be felsic rocks.U-Pb dating of detrital zircon showed that the concordant ages of the zircons are mainly distributed in three ranges,110~180 Ma,230~280 Ma,1695~2171 Ma.With the lithostratigraphic division,characteristics of trace and rare earth elements,age of magmatic rocks and regional tectonic evolution,the sediments of Yaojia Formation was believed to be originated from Ulanhot area in the southern part of the Greater Hinggan Mountains.

关 键 词：松辽盆地 姚家组 地球化学 锆石年代学 物源分析 

分 类 号：P619.14[天文地球—矿床学]