Genesis of the metamict zircons in the pegmatite from the Qinling Group(Complex) in the North Qinling Terrane

This study introduces zircon U- Pb ages for the pegmatite veins from the Qinling Group( Complex)in the Northern Qinling Belt. It presents Cathodoluminescence( CL) images for the metamict zircons in the pegmatites from the North Qinling Terrane,and suggests that the structure of zircons in the pegmatites has changed after metamictization or recrystallization,and the CL images for zircons show black color with no zone belt. The LA-ICP-MS data of the metamict zircons for four pegmatite veins show obvious Pb loss with unconcentrated ages as a result of metamictization. One sample( QL1434-1) shows concordant age of 380 Ma( Late Eopaleozoic),which is considered as the formation age of the pegmatite vein.