SHRIMP zircon U-Pb dating of the Quli quartz diorite porphyry，Sanmenxia City，Henan，and its geological significance

Abstract：Cathodoluninescence (CL) images show that there are two types of zircon in the Quli quartz diorite porphyry, Sanmenxia City, Henan Province, i.e. euhedral zircond with fine oscillatory zoning and rounded zircons with an inherited core and growth rims. SHRIMP U-Pb dating of the zircons with fine oscillatory zoning of magmatic origin indicates that quartz diorite porphyry was formed at 117.7±1.6 Ma (Early Cretaceous). SHRIMP U-Pb concordia ages of the cores of rounded zircons are 620 and 219 Ma, suggesting that the parental magma for the quartz diorite porphyry may have been derived from partial melting of basement materials of the South China block that had been modified by ultrahigh-pressure metamorphism.