Abstract:In this study, SHRIMP zircon U-Pb ages and whole-rock geochemical data are reported for the mid-Paleoproterozoic granitic gneisses from the Jiaobei terrane, southeastern North China Craton. Geochronological results reveal that the granitic gneisses crystallized at 2 184~2 112 Ma and underwent metamorphism at ~1.85 Ga. Although the samples collected from different areas show obvious differences in geochemical composition, they commonly have high SiO2, Na2O+K2O and Zr contents, high 10 000Ga/Al values, and high zircon saturation temperatures, indicating that their protoliths have an affinity to A-type granite. Together with published data in literatures, protoliths of the mid-Paleoproterozoic granitic gneisses from the Jiaobei terrane were formed at two major stages: 2.13~2.10 Ga and 2.19~2.17 Ga. By comparison with the earlier stage granitic gneisses (2.19~2.17 Ga), the later stage granitic gneisses (2.13~2.10 Ga) show higher Zr contents and zircon saturation temperatures, and relatively higher zircon εHf(t) values. We concluded that protoliths of the 2.19~2.17 Ga granitic gneisses were formed by high-temperature dehydration melting of ~2.7 Ga and ~2.9 Ga TTG in the Jiaobei terrane, whereas protoliths of the 2.13~2.10 Ga granitic gneisses originated from partial melting of ~2.5 Ga TTG in the Jiaobei terrane at higher temperature. The differences in magma source and melting temperature of the protoliths of the two stages granitic gneisses imply that the Jiaobei terrane underwent two separate extensional tectonic events during the mid-Paleoproterozoic.