湘南骑田岭矿集区深部探测剖面的稀土元素地球化学特征  

Geochemical Characteristics of Rare Earth Elements in Deep Geological Profile of Qitianling Intrusion,Hunan Province

作　　者：何晗晗[1,2] 李建康[1] 李超[3] 苏晓云[2] 赵芝[1] 张怡军 王国瑞[1] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]国家地质实验测试中心,北京100037 [4]湖南省湘南地质勘察院,湖南郴州423000

出　　处：《岩矿测试》2014年第1期110-117,共8页Rock and Mineral Analysis

基　　金：深部矿产资源立体探测及实验研究项目(SinoProbe-03-01;SinoProbe-03-03)

摘　　要：湖南骑田岭白石渡—飞仙镇剖面是我国深部探测专项工作实施的重点剖面之一,前人对该剖面穿过的骑田岭岩体稀土元素特征开展了大量研究工作,但并未系统地就岩体、风化壳及其邻近的地层等各地质单元稀土元素地球化学特征作出分析。本文运用电感耦合等离子体质谱技术,对该剖面穿切的5种地质单元(灰岩岩屑、砂岩岩屑、第四纪残破积黏土、花岗岩及花岗岩风化壳)的稀土元素含量进行分析。结果表明:①剖面中各地质体的稀土配分曲线均为轻稀土富集型,但稀土总量存在显著的差异,骑田岭花岗岩风化壳的稀土含量最高(均值605×10-6),灰岩的稀土含量最低(均值154.3×10-6);对于相同岩石类型的岩性,其稀土总量也存在着较大差异,往往是越靠近岩体的地层其稀土元素含量越高;②结合REEs-Y/ΣREEs、ΣREEs-δEu图解及前人对花岗岩中锇同位素示踪结果,推测骑田岭花岗岩混入了较多的幔源物质;③骑田岭花岗岩风化壳的稀土含量(RE2O3平均含量814.8×10-6)超过了离子吸附型稀土矿床的边界品位(重稀土RE2O30.05%,轻稀土0.07%)。研究指出,骑田岭矿集区的稀土是否以离子吸附状态存在以及能否构成工业矿床有待进一步评价。Baishidu-Feixianzhen profile in Qitianling intrusion of Hunan Province is one of the most important profiles carried out in Sinoprobe. Despite the fact that a large amount of previous research had been carried out using various methods on rare earth elements （REEs） characteristics of Qitianling granite complex, no systematical study has been undertaken on geochemical characteristics from different geological units including limestone, sandstone, quaternary eluvial clays, the plution and the weathering crust. Analysis of the REEs in the profile through Inductively Coupled Plasma-Mass Spectrometry （ICP-MS） has been carried out and is reported in this paper. The results indicate that all geology units have LREE enrichment pattern, while a great difference exists between EREEs. For the total content of REEs in Qitianling Granite, the weathering crust has the highest level of EREEs with an average value of 605 x 10-6, and the limestone has the least EREEs with an average value of 154. 3 X 10-6. In addition, the closer to the intrusions, the higher EREEs contents have in strata, even for the same lithology rock. In combination with REE-Y/EREE, EREE-~Eu diagrams and Os Isotope tracer results, Qitianling granitoids might have mixed with some mantle materials. The content of REEs in the Qitianling Granite weathering crust （average value of RE203 is 814.8 x 10-6） are more than the cutoff grade of ion-absorbed-type REEs deposit （HREE RE2030.05% and LREE 0.07% ） in the main.

关 键 词：骑田岭矿集区 白石渡-飞仙镇剖面 稀土元素 地球化学特征 

分 类 号：O614.33[理学—无机化学] P59[理学—化学]