花岗质岩石成因分类研究述评

A REVIEW OF PETROGENETIC CLASSIFICATION OF GRANITOIDS

由于花岗质岩石类型多 ,分布广 ,差异大 ,因此 ,国内外学者依据不同的判别标准提出了多种花岗质岩石的分类方案。通过对 2 0多种有代表性的分类方案的分析和对比 ,笔者认为 ,Barbarin(1999)提出的花岗岩类成因分类方案较为合理 ,但应补充橄榄玄粗质花岗岩类这一重要类型。文中较详细地介绍了Barbarin (1999)的分类方案 ,论述了含白云母的过铝质花岗岩类 (MPG)、含堇青石的过铝质花岗岩类 (CPG)、富钾的钙碱性斑状钾长石花岗岩类 (KCG)、富角闪石钙碱性花岗岩类(ACG)、岛弧拉斑系列花岗岩类 (ATG)、洋中脊拉斑质花岗岩类 (RTG)、过碱性和碱性花岗岩类(PAG)以及橄榄玄粗质花岗岩类 (SHG)的特征及其形成的地球动力学环境 ,并简要讨论了这种分类方法的优点和意义。

Granitoids display great diversity because of the variety of their origins, sources, subsequent genesis and evolution processes, and emplacement at different geodynamic environments. We have reviewed around 20 representative schemes of genetic classification of granitoids, which were proposed based on different criteria. We consider that Barbarin's granitoid classification is relatively reasonable and acceptable, but a new type of granitoids, the shoshonitic granitoid, should be supplemented to Barbarin's classification. So granitoids can be divided into eight types: muscovites-bearing peraluminous granitoid (MPG); cordierite-bearing and biotite-rich peraluminous granitoid (CPG); K-rich and K-feldspar porphyritic calc-alkaline granitoid (KCG); amphibole-bearing calc-alkaline granitoid (ACG); arc tholeiitic granitoid (ATG); ridge tholeiitic granitoid (RTG); peralkaline and alkaline granitoid (PAG); shoshonitic granitoids (SHG). The mineral assemblages, field and petrographical features, and geochemical characteristics of eight granitoid types are reviewed in this paper. The advantages and significance of this classification of granitoid are discussed briefly.