南岭地区高度演化花岗岩类的稀土元素模型

本文应用现有的理论模型和矿物／熔体分配系数讨论南岭地区高度演化花岗岩类的ＲＥＥ模型，包括重稀土富集型和稀土亏损型。在花岗岗岩浆分异演化过程中，副矿物（尤其是稀土矿物）的晶出种类，顺序和物理化学条件是控制ＲＥＥ强烈分馏的关键因素。ＲＥＥ分布型式不能简单地作为鉴别岩石成因的标志。

RARE EARTH ELEMENT MODELS OF HIGHLY EVOLVED GRANITOIDS IN THE NANL1NG MOUNTAIN AREA

Highly evolved granites are generally related to W,Sn, Nb-Ta and REE mineralization in the Nanling Mountain area. According to the REE distribution patterns, they can be divided into three categories: (1)normal; (2)HREE-enriched and( 3 )REE-depleted, and show fractional trends from earlier to later stages in multiphase intrusive complexes. Simulating calculation's by using the available theoretical models reveal that several processes, such as batch partial melting, fractional crystallization and combined fractional partial melting and crystallization (Wetzel et al., 1989), might be responsible for the evolution of the magmas, during which accessory minerals, such as sphene, apatite, allanite,monazite, xeno-time, zircon and garnet, play the most important role in REE fractionation.Such complex processes lead to the conclusion that one must be cautious when using REE distribution patterns as tracers for interpretating the genesis of granitic magmas.