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The Laoshan A-type granite is a highly evolved granite body. The study on accessoryminerals indicates that there exist differentiation and accumulation of fluids during the late stage of evolution of the granite. The released fluids are rich in rare-earth elements (REE), high-field-strength elements (HFSE, such as Nb, Ta, Zr, Hf, Th, U, and Y) and volatiles (F, P, CO2, etc.). Owing to the presence of fluid, accessory mineral assemblages have changed during the evolution of A-type granite, and are especially characterized by large amounts of independent REE-Nb-Y-Th minerals present in the late facies. Late-accumulation of fluids may be of the general feature of A-type granites, at least of highly evolved ones.
The study on accessoryminerals that that exist differentiation and accumulation of fluids during the late stage of evolution of the granite. The released fluids are rich in rare-earth elements (REE), Owing to the presence of fluid, accessory mineral assemblages have (HFSE, such as Nb, Ta, Zr, Hf, Th, U, and Y) and volatiles changed during the evolution of A-type granite, and are are characterized by large amounts of independent REE-Nb-Y-Th minerals present in the late facies. Late-accumulation of fluids may be of the general feature of A-type granites, at least of highly evolved ones.