LA-ICP-MS Zircon U-Pb Ages of the Plagioclase-Amphibole Schist from the Wuguan Group in Shangdan Area, East Qingling, and Its Geological Significance

There lacks accurate chronology information about the plagioclase-amphibole schist from the Wuguan Group of Mianyuzhui Unit in Shangdan area, East Qinling, which cause the formation age and tectonic attributes of Wuguan Group cannot to be understand. The LA-ICP-MS U-Pb dating on the zircons from the plagioclase-amphibole schist yield four age clusters of~2.45Ga,~1.7~2.0Ga,~0.95Ga,~0.85Ga. Except for the youngest one group of zircon ages, the others indicate that these zircons were inherited from the crustal materials during the ascending of basaltic magma, which were sourced from the protolith magma of plagioclase-amphibole schist and recorded the growth process of South Qinling. This result suggests that the crystal age of plagioclase-amphibole schist's protolith is~730Ma, corresponding to the break-up of the Rodinia supercontinent in Middle-LateNeoproterozoic.