幕阜山北缘断峰山地区两类伟晶岩地球化学特征及其成矿作用指示意义  

Geochemical Characteristics of Two Types of Pegmatites in the Duanfengshan Areaon the Northern Margin of the Mufushan and Its Metallogenic Significance

作　　者：任旭 朱金 李江力 刘圣鑫 刘雷 Ren Xu;Zhu Jin;Li Jiangli;Liu Shengxin;Liu Lei(Hubei Geological Survey,Wuhan,Hubei 430034;Hubei Provincial Engineering Technology Research Center for Geological Exploration,Wuhan,Hubei 430034)

机构地区：[1]湖北省地质调查院,湖北武汉430034 [2]湖北省地质勘查工程技术研究中心,湖北武汉430034

出　　处：《资源环境与工程》2023年第2期135-147,共13页Resources Environment & Engineering

基　　金：湖北省地质局2022年度矿产地质项目“湖北幕阜山北缘铌钽锂铍等战略性矿产调查评价”(KCDZ2022-15)。

摘　　要：幕阜山地区是华南重要的稀有金属矿集区,其北缘断峰山地区伟晶岩脉极为发育,伴随良好的Nb、Ta、Be等矿化。通过对断峰山地区详细的野外地质调查,选取钠长石伟晶岩和微斜长石伟晶岩为研究对象,着重分析两类伟晶岩的分类、与围岩关系、母岩类型、岩浆来源及其与成矿作用的关系。认为这两类伟晶岩均为LCT族系伟晶岩,原岩来自冷家溪群部分熔融形成的S型花岗岩,岩浆源区主要为地壳物质。断峰山地区钠长石伟晶岩与黑云母二长花岗岩为同一期次岩浆活动产物,对应幕阜山岩体第一阶段晚期岩浆活动;微斜长石伟晶岩与二云母二长花岗岩为同期次岩浆活动产物,对应幕阜山岩体第二阶段岩浆活动,两类伟晶岩之间并无成因演化关系。断峰山地区钠长石伟晶岩相比于微斜长石伟晶岩,其演化程度更高,岩浆—热液作用更显著,晚期富含挥发分和稀有金属元素(Nb、Ta、Be等)的钠质热液的交代作用形成了Nb、Ta和Be等稀有金属矿化。The Mufushan area is an important rare metal ore concentration area in South China.The pegmatite dykes in the Duanfeng Mountain area on the northern margin are relatively exposed,with good Nb,Ta,Be and other mineralization.Based on the detailed field geological survey of pegmatites in the area of Duanfengshan,this paper selects albite pegmatites and microcline feldspar pegmatites,and focuses on analyzing the classification of the two types of pegmatites,their relationship with surrounding rocks,parent rock types,magma source and the relationship between the two types of pegmatites and mineralization.It is considered that the two types of pegmatites belong to the LCT-group pegmatites,the original rocks are from the S-type granite formed by partial melting of the Lengjiaxi Group,and the magma source areas are mainly crustal material.Duanfengshan albite pegmatite and biotite granite are the products of the same magmatic activity,corresponding to the late magmatic activity of the first stage of the Mufushan rock mass.Microcline pegmatite and ermica granite are the products of secondary magmatic activity in the same period,corresponding to the second stage of magmatic activity of Mufushan rock mass,there is no evolutionary relationship between the two groups of pegmatites.The Dangfengshan albite pegmatite has a higher degree of evolution,significant magmatic-hydrothermal interaction in the late stage,and the late stage is rich in volatiles and rare metal elements(Nb,Ta,Be,etc.).The sodium hydrothermal metasomatism formed the mineralization of rare metal such as Nb,Ta and Be.

关 键 词：钠长石伟晶岩 微斜长石伟晶岩 稀有金属矿化 岩浆热液作用 断峰山 

分 类 号：P588.13[天文地球—岩石学]