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铌钽的地球化学行为特别是Nb/Ta比值的变化对于研究壳幔分异和大陆形成有非常重要的意义。岛弧玄武岩的Nb/Ta比值约在15~16(Munker et al.,2003;Munker et al.,2004),而全大陆地壳为12~13(Barth et al.,2000),因此在弧岩浆的结晶过程中必然存在铌钽的分异。弧岩浆演化的主要结晶相中只有角闪石和铁钛氧化物具有大于0.1的铌钽分配系数。金红石是铌钽在地壳岩石特别是榴辉岩中
The geochemical behavior of niobium and tantalum, especially the change of Nb / Ta ratio, is very important for the study of crust-mantle differentiation and continent formation. The ratio of Nb / Ta in island-arc basalts is about 15-16 (Munker et al., 2003; Munker et al., 2004) and the whole continental crust is 12-13 (Barth et al., 2000) The crystallization process must exist niobium tantalum differentiation. Only the amphibole and iron-titanium oxides have a niobium-tantalum distribution coefficient greater than 0.1 in the main crystalline phase of the arc-magma evolution. Rutile is niobium and tantalum in crustal rocks, especially eclogites