过铝质岩浆体系中不相容元素的地球化学行为及机理——元素对分异和稀土元素“四重效应”及其对流体作用过程的指示意义  

Geochemical Behavior of Incompatible Elements in Peraluminous Magmatic System and Its Mechanism——Fractionation of the coherent elemental pairs and the lanthanide tetrad effect in granitic magmas: Implications for melt-fluid interaction

作　　者：刘丛强[1] 张辉[1] 

机构地区：[1]中国科学院地球化学研究所,贵阳550002

出　　处：《高校地质学报》2003年第4期648-660,共13页Geological Journal of China Universities

基　　金：国家自然科学基金(40273030)及中国科学院知识创新重要方向(kzcx3-sw-124)联合资助项目

摘　　要：根据对新疆阿尔泰3号伟晶岩脉各结构带中磷灰石的微量元素组成的系统研究,并综合了目前世界上对不同演化程度的酸性岩浆岩(I型和S型花岗岩、过铝质花岗岩、花岗伟晶岩)的研究成果,对通常具有相似离子半径和相同离子电价的元素对比值变化以及稀土元素“四重效应”产生的原因进行了分析。研究认为,这些元素对的分异和稀土元素“四重效应”的产生与富含挥发分流体相的存在密切相关,流体/熔体相作用的程度可能是制约元素对分异和稀土元素“四重效应”大小的主要因素。Based on the studies on apatites from the Altay No. 3 granite pegmatite, XinJiang, China, together with those peraluminous granites and pegmatites from various areas in the world, this paper discusses the fractionation of the coherent elemental pairs that have similar ionic radii and same valences, and also the origin of the lanthanide tetrad effect. It is suggested that the fractionation of the coherent elemental pairs and occurrence of the lanthanide tetrad effect are genetically related to formation of volatile-rich fluid during magmatic evolution, and that the fractionation of the elemental pairs and the intensity of the lanthanide tetrad effect are dependent on the extent of fluid-melt interactions.

关 键 词：过铝质岩浆体系 不相容元素分异 稀土元素“四重效应” 

分 类 号：P595[天文地球—地球化学]