巴尔哲超大型稀有稀土矿床富晶体的流体包裹体初步研究  

Study on the crystal-rich fluid inclusions from the Baerzhe super-large rare elements and REE deposit.

作　　者：牛贺才[1] 单强[1] 罗勇[1] 杨武斌[1] 于学元[1] 

机构地区：[1]中国科学院广州地球化学研究所,广州510640

出　　处：《岩石学报》2008年第9期2149-2154,共6页Acta Petrologica Sinica

基　　金：国家重点基础研究发展规划项目(项目编号2006CB403504)资助

摘　　要：巴尔哲矿床是一个超大型稀有稀土多金属矿床,它受巴尔哲碱性花岗岩体(株)控制,稀有稀土矿体分布在巴尔哲岩体上部的钠长石碱性花岗岩中。本文在钠长石碱性花岗岩的石英中发现了大量的富晶体的流体包裹体,并对其进行了初步的激光拉曼光谱和显微测温研究。与一般含盐类晶体矿物的三相流体包裹体不同,巴尔哲富晶体的流体包裹体的晶体不是盐类矿物,而是长石、云母等硅酸盐矿物;同时,该类包裹体内还广泛分布着稀土碳酸盐矿物。富晶体的流体包裹体的发现从微观角度揭示了巴尔哲含矿钠长石碱性花岗岩的形成与岩浆—热液过渡阶段有直接的成因联系,并为阐述巴尔哲岩体稀土元素及氧同位素的地球化学特征提供了新思路。稀土碳酸盐矿物在富晶体的流体包裹体中广泛地分布则充分说明,巴尔哲碱性花岗岩演化到岩浆—热液过渡阶段体系内的稀土元素已经达到足以形成独立稀土矿物的富集程度,其稀土元素矿化受岩浆—热液过渡阶段的制约。Baerzhe Deposit is a super-large rare element and REE deposit. It is controlled by Baerzhe alkaline granite body, occurring in the albite alkaline granite within the upper part of the body. Abundance of crystal-rich fluid inclusions are found in the quartz of the albite alkaline granite, and investigated by Raman spectroscopy and micro-temperature measurements. Unlike the commonly observed salt rich triple-phase fluid inclusions, the crystal-rich fluid inclusions found in the Baerzhe deposit contain mostly the silicate minerals （such as feldspar, mica, etc）, and the REE minerals. The results suggest that the genesis of the ore-bearing albite alkaline granite was directly related to the magmatic-hydrothermal transition process, and provide a new idea for explaining the geochemical characteristics of REE and oxygen isotope of the Baerzhe body. The extensive distribution of the REE minerals also indicates that the REE had already been enriched enough in the alkaline granite during the rnagmatic-hydrothermal stage of magma evolution for a REE ore deposit, and the REE mineralization was constrained by the fluid derived from this stage.

关 键 词：巴尔哲超大型矿床 富晶体的流体包裹体 碱性花岗岩 岩浆-热液过渡阶段 稀有稀土元素 

分 类 号：P588.121[天文地球—岩石学] P618.7[天文地球—地质学]