上地幔不相容元素的显交代作用

通过矿物微区成分和图象分析，研究了在金伯利岩中发现的多种氧化物矿物的成分、结构特点及其相互关系．指出富含硅酸盐不相容元素的地幔流体交代、熔融先期形成的矿物以及充填作用，形成了近年来我国和南非金伯利岩中发现的多种新矿物相，包括沂蒙矿系列、蒙山矿系列、Ｋ－Ｃｒ柱红石、阿玛科矿、Ｚｒ－Ｔｉ氧化物（锆钛矿）、ＲＥＥ－Ｔｉ氧化物（铈钛矿）等．这些新矿物高度富集了Ｋ，Ｂａ，Ｃａ，Ｓｒ，Ｔｉ，Ｚｒ，ＲＥＥ等不相容元素．研究表明不相容元素的显交代作用可分早、中、晚３个阶段，各阶段不相容元素的富集程度、温压条件及流体的动力学特征等既有明显的差异性，又有一定的继承性

METASOMATISM OF INCOMPATIBLE ELEMENTS FROM UPPER MANTLE

From the chemical composition and image analyses of micro-region,the chemical and structural characteristics and their relationship of several oxide minerals found in kimberlite are studied.It is pointed out that the metasomatism,melting of the previously formed minerals,and fill-in action of the mantle liquid rich in incompatible elements resulted in the formation of several new kinds of minerals existing in kimberlite in China and South Africa,including yimengite series,mathiasite series,K-Cr priderite,armalcolite,Zr-Ti oxide,and REE-Ti oxide etc..The incompatible elements,K,Ba,Ca,Sr,Ti,Zr and REE,etc.are highly enriched in the above-mentioned new minerals.The metasomatism of the incompatible elements could be divided into three stages:early,middle and late stages.The contents of incompatible elements,temperature and pressure conditions,and the dynamic characteristic of the liquid are apparently different,but there exists certain inheritance.