Age of the Wuhe complex in tｈe Bengbu uplift：ｅvidence from LA-ICP-MS zircon U-Pb dating

Abstract：This paper reports the LA-ICP-MS zircon U-Pb dating results of garnet-plagioclase pyroxenite in the Wuhe complex in the Bengbu uplift. The cathodoluminescence (CL) images of zircons from the garnet-plagioclase pyroxenite show three textural types of zircon, i. e.：euhedral zircon of homogeneous absorption, zircons with a distinct internal structure and typical core-rim structure and euhedral zircons with typical growth zones. The zircon U-Pb dating of spots with different intensities of zircon absorption indicates that their 207Pb/206Pb ages range from 1783±8 to 1895±8 Ma and that the weighted mean age of 49 analyzed spots is 1833±8Ma. This result suggests that the Wuhe complex was formed in the Paleoproterozoic, which is in agreement with the age of formation of the central orogenic belt of the North China craton and the age of high-pressure granulite-facies metamorphism in Jiaodong, and further implies that the Wuhe complex should belong to the basement of the North China craton．