豫西卢氏稀有金属伟晶岩脉地球化学特征研究  

Study on geochemical characteristics of Lushi rare metal pegmatite dike in western Henan Province

作　　者：包民伟 康晓涛 李蓓 王昭 张苏苏 Bao Minwei;Kang Xiaotao;Li Bei;Wang Zhao;Zhang Susu(Henan Province First Geological Exploration Institute,Zhengzhou 450001,China)

机构地区：[1]河南省第一地质勘查院,河南郑州450001

出　　处：《能源与环保》2023年第7期97-104,共8页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：河南省地质矿产勘查开发局局管地质科研项目(豫地矿科研201806)。

摘　　要：豫西卢氏一带的伟晶岩脉沿灰池子岩体外围规律展布,依次为黑云母型、二云母型、白云母型和锂云母型伟晶岩。以不同类型伟晶岩作为研究对象,通过研究其地球化学特征,分析其成因以及与灰池子岩体的关系。研究发现,不同类型的伟晶岩具有相似的化学特征:高硅、富铝、富碱、低铁镁钙;Rb、Ta、U、Nb、Pb富集,La、Th、Ce、Eu、Nd亏损:稀土元素稀土含量极低,最低值为0.20×10^(-6),平均只有9.44×10^(-6),轻稀土相对富集,重稀土相对亏损。通过花岗伟晶岩与灰池子岩体紧密的时空关系及相似的岩石地球化学特征,推测以上各类伟晶岩来源于灰池子岩体的残余岩浆,该岩浆可能是深部地壳和上地幔岩石圈熔融作用的产物,在其上升过程中受到地壳的混染。Pegmatite dikes in the Lushi area in western Henan regularly distribute along the periphery of the Huichizi pluton,which are biotite,bimicite,Muscovite and limicite in sequence.In this study,pegmatite of different types is taken as the object,and its genesis and relationship with Huichizi rock mass are analyzed by studying its geochemical characteristics.The pegmatite dikes in Lushi area,western Henan Province,are regularly distributed along the periphery of Huichizi rock mass,and are in turn biotite type,bimorphite type,muscovite type and lepidolite type in sequence.Taking different types of pegmatite as the research object,through studying their geochemical characteristics,we analyze their genesis and relationship with Huichizi rock mass.It is found that different types of pegmatite have similar chemical characteristics:high Si,rich Al,rich alkali,low Fe,Mg and Ca;enrichment of Rb,Ta,U,Nb,Pb,depletion of La,Th,Ce,Eu,Nd:rare earth elements are extremely low in rare earth elements,the lowest value is 0.20×10^(-6),with an average of only 9.44×10^(-6).Light rare earth elements are relatively enriched,while heavy rare earth elements are relatively depleted.Based on the close temporal and spatial relationship between the granite pegmatite and the Huichizi pluton and the similar geochemical characteristics of the rocks,it is inferred that the above pegmatite originated from the residual magma of the Huichizi pluton.The magma may be the product of the melting of the lithosphere of the deep crust and upper mantle,and may be contaminated by the crust during its ascent.

关 键 词：伟晶岩 稀有金属 灰池子岩体 地球化学特征 

分 类 号：P588.13[天文地球—岩石学]