中国科学院地球化学研究所机构知识库

The Nanping pegmatite deposit is a large Ta-Nb-Sn deposit in the northeastern Cathaysia Block, SE China. Columbite-group minerals from zone I in the Nanping No. 31 pegmatite vein belong to columbite-(Fe). The compositions and texture features of zircon grains from the same zone identify their magmatic origin. Columbite-(Fe) U-Pb age coincides well with the U-Pb age of zircon, and these age data constrain the absolute formation timing of this pegmatite vein to approximately 387 Ma. Zircon epsilon Hf(t) values from the Nanping No. 31 pegmatite range from -13.81 to -11.60 with the T-DM2 model ages ranging from 2107 to 2246 Ma, implying that the Nanping pegmatite-forming melts are derived from Paleoproterozoic metasedimentary rocks. The differences in emplacement age and Hf isotopic features preclude the surrounding granites from being the parental granite of the pegmatite vein.