accessory species
2.The types, contents and assemblages of accessory minerals in the Archean granitoid rocks are significantly different from those in the Phanerozoic granitoid rocks. They are very simple in type (only 6-11 species), and assemblage (almost Mt + Ap + Zir(Sph)), but high in total contents ranging from 1858 to 36991 g/t. This can be regarded as a criterium for distin-guishing Archean granitoid rocks from Phanerozoic granitoid rocks.
